Hydrometer Wisdom: Monitoring Fermentation As with all matters of life, there are two ways of monitoring the fermentation of your mash: the easy way and the complicated way. If you’re a K.I.S.S. fan – not the band, but the „Keep It Simple, Stupid” philosophy – you’ll prepare the mash and just let it be.
- A day or two after adding the yeast, you’ll see the airlock bubble – and know the stuff’s doing its fermenting business.
- After 14 days, it should be about done.
- If it still bubbles, let it sit for another few days, or until you see no bubbling for at least a minute or two.
- Once there is no activity in the airlock, your mash is ready to run.
This is a non-scientific method but pretty reliable in judging when fermentation is completed. The scientific method isn’t actually that complicated either, and it will let you know that the mash has completely finished fermentation and determine its potential alcohol.
- What you’ll need is a beer or wine hydrometer.
- The hydrometer indicates the density, or specific gravity – SG – of a liquid, compared to water.
- As alcohol is thinner than water, the higher the alcohol content, the deeper the float sinks.
- Pure water has a specific gravity of 1.000 on the hydrometer scale.
Temperature is a key factor when measuring the specific gravity of a liquid – the hydrometer should indicate the temperature it’s calibrated to, and also include an adjustment table. A standard measuring temperature is 20°C or 70 °F. Original Gravity – OG Measure the gravity of your mash before fermentation – and before adding the yeast.
The reading will be higher than 1.000, because of the sugars present in the mash. During fermentation, these sugars will be consumed by yeast causing the density and therefore specific gravity to lower. The number will be the lowest at the end of fermentation. Fill your hydrometer tube about 2/3 of an inch from the top with the wash/mash you wish to test.
Insert the hydrometer slowly not allowing it to drop. Give the hydrometer a light spin, to remove the air bubbles that may have formed.
- Read where the surface of the liquid cuts the scale of the hydrometer.
- You can also predict the potential alcohol of your mash from the original gravity.
- Original Gravity – Potential Alcohol
- 062 → 7.875%
- 064 → 8.125%
- 066 → 8.375%
- 068 → 8.625
- 070 → 8.875%
- 072 → 9.125%
- 074 → 9.375%
- 076 → 9.75%
- 078 → 10%
- 080 → 10.25%
- 082 → 10.5%
- 084 → 10.75%
- 086 → 11%
- 088 → 11.25%
- 090 → 11.5%
- 092 → 11.75%
- 094 → 12.125%
- 096 → 12.375%
- 098 → 12.75%
- 100 → 13%
- 102 → 13.25%
- 104 → 13.5%
- 106 → 13.875%
- 108 → 14.125%
Final Gravity – FG Measure the specific gravity of the mash after the airlock slows down and you’re not getting much activity. If the reading is at 1.000 or less, it is definitely done. If it’s 1.020 or higher, you may want to wait a day or two and then take another reading. Keep taking readings, if needed, until the gravity stops dropping – which means the fermentation is complete.
- A good rule of thumb: if the gravity hasn’t changed over the course of three days, then the mash is done fermenting.
- Final Gravity – Potential Alcohol
- Using the chart above and some math, you can calculate the alcohol content of your mash after fermentation is complete.
- ABV = (OG – FG) x 131
For instance, if the OG reading is 1.092 and the FG is 0.99, the math goes like this: (1.092-.99) x 131 = 13.36% ABV Remember, this is a rough estimate, as many factors are at play. But the science will at least keep you busy until you’re ready to get your whiskey still running. Posted by Jason Stone on June 01, 2015 : Hydrometer Wisdom: Monitoring Fermentation
- 1 What is OG in distilling?
- 2 What does OG mean in brewing?
- 3 How do you calculate ABV from OG?
- 4 Can you determine ABV without OG?
- 5 Why is my OG so high?
- 6 What does OG quality mean?
- 7 What should my final gravity reading be?
- 8 What is OG value?
- 9 What is the difference between original extract and apparent extract?
- 10 What is the original gravity of water?
What is OG in distilling?
The Oxford Companion to Beer Definition of original gravity The Oxford Companion to Beer definition of Original Gravity (OG), sometimes called original extract, is a measure of the solids content originally in the wort, before alcoholic fermentation has commenced to produce the beer.
OG is one of the major measurements used by brewers to determine the future alcohol content of a beer fermented from a particular wort. It is measured by a saccharometer, hydrometer, or refractometer as the density of the wort at standard temperature and pressure (STP; usually 20°C and 760 mm) at the final collection point before the yeast is added.
Original gravity is expressed as the density above that of distilled water and in the UK is called the excess gravity. Water is deemed to have a density at STP of 1.000. If the wort density is 1.048, it will have 48° of excess gravity and an OG of 48. Internationally, different units are used to express OG that are unique to the brewing industry and include degrees Plato, degrees Balling, or percent dry matter of the wort, Brix % (for sucrose only).
These units take into account the solution factors of carbohydrates and mixtures of carbohydrates typically found in wort made from different cereal/malt recipes (e.g., barley malt, maize, rice, sugar). The numerical figure for these units approximates one-quarter of the excess gravity. In the example above 48/4 = 12% dry matter by weight or 12° Balling or 12° Plato.
Laboratory procedures can be used to establish the original gravity of a beer by measuring both the present or apparent specific gravity of the beer and the alcohol content of the beer, the latter by distillation. Original gravity tables convert the alcohol content back to the amount of carbohydrate fermented to produce it.
- Then, by the addition of these two values, the wort’s original gravity can be established from the tables.
- Tables for converting alcohol content to a value for carbohydrate fermented were first produced in 1850 by Graham, Hofman, and Redwood and were incorporated into the UK 1880 Inland Revenue Act for excise duty collection calculations as Statutory Tables.
They were found to give inaccurate results under certain circumstances (Section 15 of the Act Export drawback, etc.) so in 1910 after a Joint Inquiry led by Sir T.E. Thorpe and Dr H.T. Brown of the Institute of Brewing, they were refined to accord with “brewing operations as carried out in present day brewery practice.” The use of high-gravity brewing technology and postfermentation dilution is ignored by this analysis because it measures the OG as if no dilution had occurred.
Brewers seek to achieve consistent original gravities for their worts as part of overall quality assurance for their beers. See also,, and, Broderick, H.M.,, The practical brewer, St Paul, MN: Master Brewers Association of the Americas, 1993. Graham, T., A.W. Hofman, and T. Redwood, Report on original gravities,
Quarterly Journal of the Chemical Society 5 (1852): 229. Hopkins, R.H., and B. Krause, Biochemistry applied to malting & brewing, 2nd imp. London: Allen & Unwin, 1947. Hough, J.S., D.E. Briggs, R. Stevens, and T.W. Young, eds. Malting & brewing science, 2nd ed.
What does OG mean in brewing?
What is gravity? – Gravity is a measurement of beer’s density. An original gravity (OG) reading indicates the number of dissolved sugars in the beer that can be converted into alcohol. These sugars come from malted grain and are later consumed by yeast to convert wort into beer. In short, the OG is an indication of the beer’s potential alcohol percentage.
What is OG in wine?
How do I deal with measuring alcohol in my beer, wine, mead, etc.? – When measuring alcohol, using a hydrometer, take a Specific Gravity reading before adding yeast and just before bottling. These are the two minimum times to take a readign to be able to calculate the alcohol content in your fermented beverage.
- The hydrometer is used through out the fermentation to determine if sugar is being converted into alcohol.
- As more sugar is converted to alcohol the Specific Gravity will fall.
- The Original Gravity (OG), the gravity just before adding the yeast, of a typical wine will be 1.075 to 1.090.
- Depending on the temperature and the activity of the yeast, this will change on a daily basis by about 10 points.
After a few days the gravity will have typically dropped to 1.040. The Final Gravity (FG) of a wine will be in the region of 1.000 to 0.990.
How do you calculate ABV from OG?
Homebrew Dad’s Alcohol by Volume Calculator Looking for homebrewing gift ideas? Check out our previous gift guides or ! Also, if you enjoy BrewUnited, please consider doing your Amazon shopping via our ! It never hurts to have another hydrometer on hand! The most accurate ABV calculator on the internet.
- The amount of alcohol in your beer is determined by measuring your original gravity prior to fermentation, then your final gravity after fermentation is complete.
- Unless you add other fermentables (most often, fruit or additional sugars) after you take your original gravity reading – which have to be accounted for on their own – you can simply use these two number to calculate the amount of alcohol by volume.
This is due to the fact that alcohol is less dense than water; therefore, as your wort ferments (and the sugars are converted to alcohol), the density of the beer decreases. The basic formula used by most homebrewers is pretty simple: ABV = (OG – FG) * 131.25,
ABV = alcohol by volume, OG = original gravity, and FG = final gravity. So, using this formula with a beer having an OG of 1.055 and a FG of 1.015, your ABV would be 5.25%. There is one caveat – this formula only yields an approximate ABV. In actuality, the formula becomes less precise as alcohol levels increase.
There is a more precise way to figure your alcohol content, but it requires quite a bit of math to do so, unless you already have an accurate alcohol by weight measurement. ABV = (ABW * (FG /,794) ) Where ABW is alcohol by weight. To get alcohol by weight, you must know that original extract value (which is figured from the orignal gravity of the beer) and the real extract value (which is figured from apparent extract, which in turn is figured from the measured final gravity of your beer, as well as the atteunation coeeficient, which is figured from the original extract number).
- Extract, incidentally, is measured in degrees Plato.
- That formula, if you care, follows.
- ABW = (OE – RE) / (2.0665 – (.010665 * OE) ) Using our sample beer above (OG 1.055, FG 1.015), we find that our simple formula was actually quite accurate – we get a rounded value of 5.25%.
- The differences between the two formulae does, however, grow greater as the alcohol content grows.
Let’s use a bigger beer as a second example. This one has an OG of 1.086, and a FG of 1.019. With the simple formula, we get an ABV of 8.79%. With the more complex formula, we get a measurement of 8.87% A third example is a barleywine with an OG of 1.120 and a FG of 1.030.
- The simple formula gives us an ABV of 11.81%.
- The more complex formula gives us a mark of 12.05% ABV for this massive beer.
- The precision level of the calculation may or may not matter to you; many homebrewers use an even simpler version than the simple formula above (ABV = (OG – FG) * 131), and figure that it is close enough.
That being said, you might find this little calculator to be useful or enjoyable. and if nothing else, non-math whizzes should find it to be a lot easier than trying to use the more complex formula. Credit for the math goes to Dr. Michael Hall, in his article entitled “Brew by the Numbers – Add up What’s in Your Beer” ( Zymurgy, summer 1995).
Can you determine ABV without OG?
A combination of a refractometer and a hydrometer can be used to determine % alcohol from a finished beer, no knowledge of OG required.
Why is my OG so high?
High Gravity Beer Basics – High-gravity beer, often called “big beer,” is bold, flavorful and powerful. Everything about these beers is substantial, from their intense flavor and other exaggerated characteristics to their generally higher alcohol content (the percentage varies from state to state for what is considered high gravity by law). Common High Gravity Beer Styles
Barley Wine Imperial Porter / Imperial Stout Scotch Ale / Wee Heavy Imperial IPA Wheat Wine Ale Barrel-Aged Beer Belgian-Style Golden Strong Ale
“High-gravity” refers to brewing a beer with high original gravity (OG)—typically, above 1.075 OG is considered high. OG is a measure of the fermentable and un-fermentable substances in the wort before fermentation. This is measured after the initial boil, before the yeast is pitched, and will be used later in conjunction with the final gravity reading to calculate the alcohol percentage.
What does OG quality mean?
Here is the list of the most important sneaker terminologies you should know – GR: GR stands for “General Release.” GR sneakers are your AF1s, adidas Forums and 550s: the sneakers you can walk into a store and buy for retail price. If you want to get very technical, GR can mean any sneaker released to the public, which would include collaborations.
But generally, when people say GR, they mean sneakers that are very widely available. OG: OG is probably one of those sneaker terms you have heard before, it stands for “Original” – although, as aforementioned, it once stood for “Original Gangster.” The term OG may be used to refer to the earliest release of a silhouette, a classic colorway, or a faithful reissue.
PE: PE stands for “Player Edition” or “Player Exclusives.” Quite simply, this means the shoe has been created especially for a certain athlete – typically a basketball or American football player. Real PEs are incredibly hard to come by, though some PEs have been later released to the public. WTB: WTB stands for “Want To Buy.” This abbreviation is used by collectors and hypebeasts alike who are yearning for a specific pair of sneaks. You’ll most likely find this abbreviation in buying and selling groups. WTS: WTS stands for “Want To Sell.” Needless to say, this abbreviation is popularly used on the resale market by those who are keen to part ways with a pair of kicks.
WTT: WTT stands for “Want To Trade.” Browse through a sneaker forum, and you’re likely to spot this abbreviation several times, followed by a list of sneakers the person is willing to accept as trades. BNIB: BNIB stands for “Brand New In Box.” Frequent sneaker sellers employ this abbreviation to inform buyers that a particular pair of sneakers are unworn and will be shipped in their original box.
DS: DS is a very common sneaker term that stands for “Deadstock.” DS shoes are box-fresh pairs of releases that are no longer purchasable outside of the resale market. Similar to GR, deadstock’s actual meaning has changed over the years. It technically means that the sneaker is no longer sold by retailers, but it has been adapted to mean box-fresh sneakers that have never been worn. TTS: TTS stands for “True to Size.” This abbreviation is applicable to sneaker models that provide the intended on-foot experience if you purchase them in your accurate shoe size. W: W stands for “Women’s.” If the name of a sneaker is punctuated by W, it’s paramount that you remember to opt for your women’s size, not your men’s size, when purchasing the shoe.
What is a good original gravity?
As Mythbusters’ ballistics expert, Adam Savage, has said: “Remember kids, the only difference between screwing around and science is writing it down.” During the brew day, one of the most important things to write down and one of the very last things to write down is Original Gravity.
Original Gravity dictates whether the desired ABV will be achieved in a brew. It dictates whether the hop additions will provide the desired balance. It determines whether or not the brew day went as planned. Ultimately, it’s a measure of how well the brewer knows their brewery. Gravity is a key measure in physics and petroleum as well as brewing and winemaking.
In physics gravity is the force bringing objects together. In the contexts of petroleum and fermentation, gravity is the measure of a liquid’s density relative to water at a specified temperature. Within brewing and winemaking, the difference in density is a result of dissolved, fermentable sugars. The color of a beer can provide clues to its density. The higher the density of a beer, the higher its gravity will be. Gravity measurements, or ‘specific gravity readings’ are made at key points throughout the wort-making and fermentation process; prior to boiling the wort (“pre-boil gravity”), immediately prior to pitching the yeast (“original gravity”), and post-fermentation (“final gravity”).
- These readings are usually taken with a floating hydrometer or refractometer.
- A hydrometer is a tall, thermometer-like glass instrument placed within the sample of the liquid to be measured.
- A refractometer is a monocular-like instrument with a glass prism where a drop of the sample liquid is placed.
- Hydrometers and refractometers expect the wort to be at a calibrated temperature – usually 65˚F.
Calculations exist to adjust the readings taken at higher temperatures – though this is less of a concern with the refractometer because the sample size, a drop from a pipette, cools much faster than the 130 millileters of sample required by the hydrometer.
These dissolved, fermentable sugars were extracted from the beer recipe’s grist – the barley, malt extract, adjuncts, or sugars – as part of the brewing process.The amount of sugars within a fermentable ingredient is measured in Points Per Pound Per Gallon (PPG), or the specific gravity reading from extracting 100 percent of the sugars of one pound of the fermentable within one gallon of water.
Each ingredient has a different amount of available sugars; Liquid malt extract has 36 PPG, American 2-row barley has 28, wheat has 38. No all-grain brewhouse can extract all 100 percent of the fermentable sugars. Commercial breweries aim to extract 80 to 90 percent of the sugars where as many homebrew-scale recipe writers assume the homebrewer’s system can achieve only 70 percent. A simple American Pale Ale recipe may include 9 pounds of 2-Row and,25 pounds of Crystal 40L. The 2-Row has a 37 PPG and the Crystal has a 34 PPG. On my homebrew system, I usually brew six gallon batches and average 70% efficiency. By multiplying each grain’s PPG by the number of pounds used divided by the batch size in gallons (37*9/6=55.5 for the 2-Row and 34*.25/6=1.4 for the Crystal) the maximum gravity I could reach would be 55.5+1.4 = 56.9.
- Rounded and converted to a specific gravity reading gives us 1.057 Original Gravity.
- That’s if 100 percent of the sugars were extracted.
- Multiplying the 57 by my 70 percent brewhouse efficiency gives us 39.9, or and expected original gravity of 1.040.
- The amount of sugars extracted stays constant (through PPG & efficiency), it’s the volume of liquid changing the gravity.
Which means, if I took a gravity reading at the end of the brew day and discovered I extracted more than 70 percent of the sugars. I could dilute the batch with more water bringing down the OG. If I extracted less than 70 percent, I could boil longer or add an easily dissolvable fermentable like honey (36 PPG) or corn sugar (46 PPG) at the end of a boil to achieve the target Original Gravity.
A brewer with the same recipe and an 85 percent efficiency could achieve the same 1.040 target OG with just 7.4# of 2-Row and 3.3oz of Crystal. Conversely, if they brewed with my 9 pounds and 4 ounces their 85 percent efficiency would result in a 1.048 OG. This substantial difference is why professional brewers talk in percentages – rather than pounds or kilograms – when describing a recipe, e.g.
“97.3% American 2-Row, 2.7% American Crystal 40L, to 1.040 OG.” This concisely describes the ratio of ingredients and target gravity, while leaving out the brewhouse-specific efficiency.
What should my final gravity reading be?
The Final Gravity is the specific gravity measured at the completion of fermentation and represents the amount of unfermentable sugars remaining in the beer. You can calculate the approximate alcohol by volume (abv) of the beer by subtracting the original gravity (OG) from the final gravity (FG) and multiplying it by 131: (OG-FG)*131=abv.
- You can estimate the approximate finishing gravity of a beer by taking into account the attenuation rate of the yeast strain you are using.
- For example if you have a yeast with a 75% attenuation rate and your original gravity is 1.050 the estimated final gravity would be about 1.012.
- This is merely a estimate and can be lower or higher because there are many factors that affect the final gravity.
These factors include fermentation temperature, amount of yeast pitched, the health of yeast, the amount of O2 present, mash temperature, the amount of adjuncts used, the amount of nutrients available in the wort, and the flocculation rate of the yeast strain. Be the first to know about the latest homebrewing gadgets & gizmos.
What is OG value?
OG Price Live Data The live OG Fan Token price today is $10.45 USD with a 24-hour trading volume of $33,724,826 USD.
What is a good hydrometer reading?
How To Use A Hydrometer (The Easy Way) – By BREW MART Today I am going to show EXACTLY how easy it is to use a hydrometer. In fact this is the same process which has allowed me to brew excellent beer, wine and cider during the last few years. And I will let you into a secret – it is not rocket science In fact if you are not scientific like me you will love this easy to follow guide LET’S DIVE STRAIGHT IN
What is a hydrometer? How do I use a hydrometer to calculate ABV? Using a hydrometer when making wine Using a hydrometer when making beer How to measure the specific gravity using the hydrometer How to use the hydrometer using a four-step process Stage 1: Using the trial jar with the hydrometer Use a Wine Thief Stage 2: Obtain the Original Gravity Reading Stage 3: Calculate with Temperature S tage 4: Obtaining the final gravity reading (FG) Temperature Correction Chart for Hydrometer Reading
WHAT IS A HYDROMETER? A hydrometer is a straightforward device that measures the density of a liquid comparing it to water. It usually comes with a thin plastic case to help to protect it and uses a scale called specific gravity or just gravity for short. It works on the same principle as floating in the dead sea.
- The dead sea is so easy to float in because it is full of dissolved minerals.
- Much like in the Dead Sea, the more dissolved sugar there is in a beer or wine solution, the higher the hydrometer floats, giving a higher reading on the hydrometer’s scale.
- The easiest way to use a hydrometer is to collect a sample of the must (wine) or wort (beer) using a sterilised and rinsed wine thief (pipette), and a trial jar.
A hydrometer is for use in any wine, beer or cider making situation. In terms of brewing beer, wine or cider the hydrometer measures the amount of dissolved brewing sugar in the recipe. If you notice the amount of sugar going down, fermentation is working, and alcohol is increasing.
The measurements/readings show how the yeast is turning sugar by volume and lets you know how well the fermentation process is coming along. A hydrometer looks like a round pointy glass rod with lines on it to use as a measurement. It is much like a thermometer used for inserting under the tongue except that one end of it is fatter.
Depending on how much the hydromtera floats or sinks in various liquids, you can measure how dense the fluids are. Brew Mart’s recommendation is to use a trial jar which is a specific jar to use with the hydrometer for this purpose. A trail jar made from plastic is better than a glass one as the glass ones can break easily. The trial jar is 20cm long and has a diameter of approximately 3.5cm. and has measurements on the side. This enables you to fill the right amount of liquid leaving a space at the top for the insertion of the hydrometer in order to test the results.
- Take care to use the same hydrometer for each measurement in the same experiment as different hydrometers may vary a little.
- The analysis of pure water at 20°C – 68°F will have a gravity of 1.000.
- This reads one point zero zero zero).
- Add sugar to the water, and the gravity will increase.
- Adding alcohol to the pure water the gravity will go down as alcohol is less dense than water.
As things heat up, they get less dense. Using the same hydrometer and sugary water, now at 40°C – 104°F, the water will appear to have a lower gravity. If your liquid has a much different temperature to 20° C, you can also use an online calculator or app to calculate how the reading due to the differing temperature is effected.
- What this means is that you can tell how well your wort or must is fermenting by taking a reading of the original gravity (OG) before you add your yeast.
- Taking this reading is a critical measurement as it indicates the amount of sugar you can use.
- The beer or wine yeast then turns the sugar into alcohol which in turn gradually reduces the gravity until it reaches the final gravity (FG).
The final gravity (FG) is as low as the gravity will reach. Despite the alcohol content, the gravity will usually never reach lower than 1.000. This measurement is because residual proteins and un-fermentable sugars are present in the liquid. The yeast can not metabolise these remaining proteins and un-fermentable sugars.
By knowing the original gravity (OG) and final gravity (GF), you can find out how much alcohol has been produced and therefore the alcohol content of your beer or wine, which will help determine your ABV (Alcohol by Volume). How do I use a hydrometer to calculate ABV ( Alcohol by Volume)? The ABV can be worked out only by taking the start gravity from the final gravity and dividing this figure by 7.362.
As an example, the starting point for your wine is 1.080 this then ferments down to 0.990. The drop is 90 points.90 divided by 7.362 is 12.23% ABV. Using a hydrometer when making wine The starting gravity should usually be between 1.070 to 1.090 and the usual finished ABV will be between 10.5% to 13%.
- Finish Gravity is typically 0.990 (for dry wines) to 1.005 (for sweet wines).
- Brew Mart always recommend that wine should be fermented down to dryness and if you require a sweeter wine adding sugar or grape juice at the end will increase the sweetness.
- Using a hydrometer when making beer It can be complicated to give a definitive guide when brewing beer as there are so many beer brewing variations.
A typical beer will start (OG) at 1.045 and finish (FG) at 1.012 giving a 32 point drop (divided this by 7.362) making it 4.5%ABV. How to measure the specific gravity using the hydrometer By using the hydrometer, you measure how dense your beer or wine is. This measurement means that you can estimate how much-dissolved brewing sugar is in the brew. The gravity of the unfermented wort or must is called the original gravity (OG). The hydrometer will show you the current density of the brew and can indicate the rate at which the yeast is converting the brewing sugar into alcohol.
- This new measurement helps you assess the success and health of the fermentation.
- This stage is the most delicate stage of brewing.
- It is also the stage when by reading the information which the hydrometer gives you, you can make adjustments to your brew.
- How to use the hydrometer using a four-step process Step 1: Using the trial jar with the hydrometer Take the first measurement before you pitch your yeas t s once the wort has cooled down to the optimum temperature required for the yeast.
This is commonly 20°C/68ºF for beer or wine and 15°C /59°F for lagers, this allows you t o obtain the OG (Original Gravity). When using the hydrometer, many people say that you can drop it into the bucket containing the wort. Brew Mart do not recommend this as it increases the risk of contamination, even if everything has undergone sterilisation. Use a Wine Thief The best practice is to use a wine thief with a trial jar. Draw the wort or must into the trial jar using the tap on your fermentation bucket or a wine thief to transfer the liquid. Half fill the trail jar to avoid spillage from displacement, then entirely suspend the hydrometer into the liquid.
- Place the trial jar on a flat surface.
- Carefully place the hydrometer into the trail jar, it can move about a little, wait for it to settle down, you can also give it a little spin at this stage to eliminate any air bubbles.
- It also makes sure that the hydrometer is not sticking to the side of the trial jar.
Step 2: Obtain the Original Gravity Reading You will notice that the surface of the liquid in the trial jar is slightly concave (U-shaped) – this is called the meniscus. The accurate reading to take is the level at the centre/base of the curve. Take note of this reading. This reading will enable you to work out how strong your fermented beer or wine is later in the process.
- The reading will depend on the beer or wine kit you used, how much you diluted it and the amount of sugar you added.
- A typical beer wort OG will be between 1.035 and 1.060.
- Your ingredient kit will list an OG so that you’ll have a reference for what your wort’s OG should be.
- A typical wine must OG is between 1.075 to 1.090 (a lot of instructions will leave out the point and write 1090, for example).
In a few days, the gravity will have dropped to 1.040 and will finish in the region of 1.000 to 0.990. Brew Mart does not recommend that the liquid in the trail jar is poured back into the bucket; you can either discard it or drink it. Remember that specific gravity is heavily influenced by temperature. Knowing the temperature of the wort is critical for reading the original gravity (OG). The best practice is to use the hydrometer when the wort or must temperature is 15°C – 59°F for lager or 20ºC – 68ºF for beer or wine. Use a stick on thermometer that sticks to the side of the fermenter, to measure the temperature of the main batch.
- Doing this is safer than using a thermometer and inserting it into the liquid and potentially ruining your brew by adding bacteria.
- If the temperature reading is different, you can use the table below to work out the accurate reading.
- Step 4: Obtaining the final gravity reading (FG) When the fermentation process is nearing completion or better still actually completed another hydrometer reading is needed to obtain the final gravity (FG).
Don’t be tempted to take this reading to soon as the recommendation is only to do two readings — one to obtain the original gravity and one to get the final gravity. Care must be taken each time not to expose your beer to harmful air or bacteria which could spoil the entire batch.
- At the final gravity stage, your wort is now officially a beer, and the final gravity reading should be close to the FG reading in the instructions of the home brew beer kit used.
- A typical beer’s FG is between 1.015 and 1.005 and should be about 1/4th or 1/5th of the beer’s OG.
- If additional testing is needed, possibly due to a stuck fermentation, do use extreme caution to limit exposure to harmful bacteria.
If fermentation is not complete, i.e. the hydrometer is not reading 1.010 or below, then fermentation has stuck and needs re-starting. If fermentation is not complete, it typically requires a “re-start” yeast and doing that should sort out any problems and start the fermentation process once more.
Check out all brew Mart’s home brew hints & tips A guide to brewing
What is 80% proof in ABV?
If liquor is bottled at 80 proof, that means it has an ABV of 40%.
What is 0.5% alcohol ABV?
Around the world, 0.5% ABV (alcohol by volume) in a beverage is recognized as non-alcoholic. We often get questions about what 0.5% ABV means for their lifestyle so we thought we’d put the answers in a post.
What does 12.5% ABV mean?
Calculating units – The number of units in a drink can be calculated from the alcohol by volume (ABV) and the size of the drink. The higher the ABV, the stronger the drink. You can find the ABV on the labels of alcoholic drinks where it’s sometimes written as “vol” or “alcohol volume” with the number of units in a bottle often illustrated on the back.
How do you test for original alcohol?
The short answer – People making their own alcoholic beverages often calculate the percentage of alcohol by volume by measuring their density with a hydrometer or their sugar content with a refractometer. These simple instruments cleverly detect how much sugar gets converted into alcohol during the fermentation process.
- Larger manufacturers may call upon laboratories that can analyze their beverages with more advanced techniques, including methods known as distillation and gas chromatography.
- If you’re an adult of legal drinking age, you might occasionally enjoy a glass of wine, a can of beer, or another alcoholic beverage.
And if you’re really into beer or wine, you may make your own. If you’ve opened a bottle of beer or wine recently, you may have noticed the alcohol by volume (ABV) percentage on the label. The ABV tells you the percentage of alcohol (ethyl alcohol, or ethanol) content in an alcoholic beverage. This brewing stage shows the dry hopping process of adding hops, green cone-shaped flowers of the hop plant, which add different flavors and aromas to beer and is commonly done in brewing for pale ales and India pale ales (IPAs). Credit: A. Urbas/NIST Let’s suppose the ABV of a beer is 5%.
- That means if you poured the beer into 100 equally sized tiny cups, then five of them would contain alcohol and 95 would contain the other ingredients.
- Of course, you can’t really split up drinks this way without very fancy chemistry equipment, but maybe this mental picture gives you a better idea of what ABV means.
A standard drink in the U.S contains about 14 grams of pure alcohol, according to the Centers for Disease Control and Prevention, Different kinds of drinks may contain the same amount of alcohol but have very different ABVs because of their serving sizes.
12 ounces of regular beer = 5% ABV 5 ounces of wine = 12% ABV 8 ounces of malt liquor = 7% ABV 1.5 ounces or a “shot” of hard liquor (gin, rum, vodka, whiskey, etc.) = 40% ABV
ABV percentages can vary within a class of alcoholic beverages. For example, red wines tend to have higher ABV, such as a merlot (13%-14%) compared with white wines like pinot grigio (12%-13%). How do manufacturers — and homebrewers — accurately determine the percentage of alcohol in the beverages they make? We’ll look at the different ways of measuring the alcohol percentages in common beverages.
- If you’re making your alcoholic beverage in your basement or vineyard, you’ll probably use one of two inexpensive methods for measuring the alcohol content in your final product.
- One method involves an instrument called a hydrometer, which typically consists of a small weighted tube with a numerical scale on it.
In this method, you submerge the hydrometer tube into a container with a sample of your alcoholic beverage in it. The tube will sink by an amount that depends on how dense your alcoholic liquid is. The density of the alcoholic liquid will change during fermentation, as sugar gets converted into alcohol (and for beer, bubbles of carbon dioxide, too).
Before fermentation, the liquid (containing sugars that will be converted to alcohol) is denser than alcohol, and because of this, the hydrometer floats more before fermentation. After fermentation, the sugars are converted to alcohol, and the hydrometer will sink more after fermentation. To measure ABV, you make two measurements with the hydrometer, one before fermentation and one afterward.
With these measurements, you are basically finding out how much sugar in the beverage changed into alcohol during fermentation. By subtracting the first reading from the second one, and then making a simple calculation, you can find out how much alcohol is in there.
- To accurately calculate the ABV, a number of important factors need to be taken into account.
- Temperature can affect the density, as well as the release of carbon dioxide bubbles in the case of beer.
- Manufacturers of hydrometers provide formulas and charts that make it easier for homebrewers and winemakers to convert their readings into an accurate ABV result.
(Creating these formulas and charts requires lots of good chemistry and physics measurements too.) A hydrometer is a tubelike instrument brewers can use to help calculate the alcohol by volume (ABV) percentage of their beers. Credit: Shutterstock/BDoss928 An alternative to using the hydrometer is a refractometer, another simple instrument that can be used to measure concentration of substances dissolved in a liquid.
- When light hits a liquid, it changes direction, a phenomenon known as refraction,
- Refractometers measure the degree to which the light changes direction.
- In an alcoholic beverage, the amount of sugar as well as alcohol greatly affects how light refracts in the liquid.
- Homebrewers, whiskey makers, wine makers and even wine grape growers (vignerons) use the refractometer to measure the concentrations of sugar in the wort — the liquid extracted from the mashing process when brewing beer and whiskey.
Within the instrument is a measurement scale (usually one called the Brix scale, or the similar Plato scale) that is used to indicate the concentration of sugar. Once yeast is added to the wort, it ferments, converting the sugar in the wort to alcohol.
To calculate the ABV, brewers need to measure the sugar concentration of the wort before it ferments, and afterward once fermentation stops. Other factors, such as temperature, the amount of alcohol produced, and other components extracted from ingredients such as barley in beer, will change the amount of refraction that occurs throughout the fermentation process.
So, to get an accurate ABV, numerous factors must be taken into account to make a good calculation. Refractometers are commonly used to measure the starting sugar concentration before fermentation and less so afterward because it requires more extensive corrections compared with hydrometer measurements and is less precise at this point.
- Larger wineries and manufacturers may call upon laboratories that have more advanced methods for measuring ABV in alcohol.
- Two common methods they can use are distillation and gas chromatography.
- Distillation refers to the process of separating alcohol from the rest of the liquid by boiling and condensation using specialty glassware.
The second method, gas chromatography, is considered the most accurate method for measuring alcohol content. It involves separating and analyzing compounds by turning the mixture into a gas. The gas then moves through a column containing a solid or thick (viscous) liquid substance known as the “stationary phase” that is able to separate components based on their physical and chemical properties.
These separated components can then be detected and quantified using a detector. Measurements are important in not only understanding how laboratories get specific percentages and numbers but also how they relate to us every day. Standards for making accurate measurements go hand in hand with the measurements themselves because they validate the results we see and enable us to trust them.
So, next time you pick up a bottle of wine or a six-pack of beer, you’ll know how the ABV percentage is measured and what it means.
What is the difference between original extract and apparent extract?
What is attenuation in beer? –
- Attenuation in beer occurs during its brewing process, specifically during fermentation.
- In this phase, the consumes the sugars extracted from the malt during mashing.
- Before they start to ferment, we need to know their concentration.
- Attenuation is the transformation and measurement of the sugars consumed by the yeast during this process,
- To understand when attenuation intervenes, it’s important to understand some concepts related to the reactions that occur in the fermentation process itself, such as:
- – Original extract, which means the amount of sugars formed by wort, both fermentable and non-fermentable.
- – Apparent extract, that is, the amount of sugars that remain in the beer after fermentation.
- – Apparent attenuation, which is the percentage of fermented sugars.
– And finally, real attenuation, which is the percentage of fermented sugars, taking into account the real density that remains in the beer, as well as the density loss caused by the generation of ethanol, the value of which is 0.798g/ml, lower than that of water, which is 0.998g/ml. Understanding these concepts precisely, knowing how to apply them and reading the information they give us in detail, will help mitigate possible faults during the process. Among other things, because a situation where the attenuation data do not match the information provided by the supplier of the yeast can lead to that must be dealt with along the way, such as an erroneous “pitching rate” (inoculation rate in beer lingo), fermentation outside the optimal temperatures ranges, or poor yeast health.
How do you calculate FG from OG and attenuation?
How to measure attenuation – You can track your attenuation by using a hydrometer or a refractometer. A hydrometer measures the specific gravity — the density of a solution, relative to pure water — by buoyancy. The higher the specific gravity of a solution, the higher the hydrometer floats.
- A Brix refractometer measures the concentration of sugar (specifically sucrose) in a solution, based on the refraction of light.
- The higher the sugar concentration, the greater the angle of refraction.
- The hydrometer is the more applicable device for measuring attenuation because it allows you to directly calculate the apparent attenuation of the beer.
Apparent attenuation is calculated using the following simple equation: AA = (OG – FG)/OG where AA is apparent attenuation and OG and FG are the original and finishing gravities, respectively, expressed in “gravity points.” For example, if a beer’s OG is 1.050 and it finishes at 1.010, then the apparent attenuation is (50 – 10)/50 = 80%.
- The actual attenuation (called real attenuation) is less than the apparent attenuation because the density of alcohol is about 80% that of water.
- In other words, the more alcohol in solution, the lower the hydrometer floats.) If you had a 1.040 beer and achieved 100% real attenuation — in other words, if the yeast consumed all the sugars (and other solids) in the wort, leaving only water and ethanol — the final gravity of the beer, as measured by a hydrometer, would be about 0.991.
(This corresponds to the roughly 5% alcohol by weight.) The apparent attenuation of this beer would be 122%. A refractometer measures the degree to which a solution refracts or bends light. Refractometers are a quick and easy way to measure wort density, but the instruments used by homebrewers are read in °Brix and this number has to be converted to specific gravity in order to calculate the apparent attenuation.
Another twist to using refractometers in brewing is that the amount of refraction is based on solution of pure sucrose (table sugar). Wort typically consists of only about 6% sucrose, with the rest being predominately maltose, maltotriose and larger dextrins. Thus to convert the refractometer scale from °Brix to °Plato, you need to divide the reading by 1.04.
To convert °Plato to specific gravity, the approximation equation is: SG = 260/(260 – P) Of course, another way to approximate specific gravity from °Plato is to simply multiply by 4, but that approximation gets worse at higher specific gravities, to the extent that it’s not very helpful over 13 °P.
- Refractometers are great for measuring wort OG, but once fermentation has started, the rising alcohol percentage changes the reading and you won’t get an accurate answer to your attenuation question.
- An equation to measure alcohol by volume with a refractometer still requires a hydrometer reading.
- In short, measuring your wort gravity with a hydrometer before and after fermentation will allow you to easily calculate apparent attenuation.
In most “normal,” all-malt beers, apparent attenuation is in the neighborhood of 75%. This gives us an extremely quick and dirty way to estimate FG to within a few gravity points — just divide the OG by 4. (For example, for an OG 1.048 beer, the estimated FG would be 48/4 = 12, or an FG of 1.012.) For a better estimate, most yeast manufacturers give the typical range of attenuation for the strains they sell.
What is the difference between specific gravity and original gravity?
Specific Gravity (SG) is a measure of the relative density of one material compared to another. For brewing, the reference material is water, so the specific gravity of wort or beer is simply the density of the liquid divided by the density of water. This results in a dimensionless number, which by brewing convention is usually listed to three decimal places.
- For example, pure water would have a specific gravity of 1.000, while an unfermented wort might have a specific gravity of 1.048.
- Finished beer would typically have a specific gravity in the 1.005-1.015 range.
- The specific gravity measure is somewhat ambiguous, since the density of water does vary with temperature, but by convention specific gravity in brewing is typically measured by a hydrometer calibrated to 60 F.
The measured value should be adjusted based on the actual temperature of the measured fluid. Specific gravity is typically measured at several points during the brewing process – after sparging, before fermentation and after fermentation. The gravity measured before fermentation is called the Original Gravity and the measurement after fermentation is called the Final Gravity,
What is the original gravity of water?
Specific Gravity – Specific gravity is the (unit less) ratio of the solid wood density to the density of water at the same temperature. The solid wood density may be determined using the green volume, the ovendry volume, or intermediate volumes. This is notable as wood shrinks about 8%–15% as it dries.
The basic specific gravity always uses the green volume. Softwoods have typical specific gravities of 0.35–0.50 g/cc on a green volume basis but can vary from 0.29 to 0.60 among North American commercial species; hardwoods have typical specific gravities of 0.35–0.60 on a green volume basis but can vary from 0.30 to 0.90 among the North American commercial species.
Balsa wood, used in model building, has a basic specific gravity of 0.16, whereas ironwood is 1.05. The specific gravity of the cell wall material is 1.50. Note that (using appropriate units): Specific gravity of wood × Density of water = Solid wood density.