As a homebrewer, it’s important to understand how to measure alcohol content in beer so that you can enjoy the perfect brew every time. Knowing the alcohol content helps you track your brewing progress and ensures you get the desired flavor and strength.
How to Measure Alcohol Content in Beer
The best way to measure alcohol content in beer is using a brewing hydrometer or a refractometer. A hydrometer measures the specific gravity of the liquid, while a refractometer measures the sugar content in the brewing recipe. These two pieces of equipment detect the amount of sugar consumed by yeast to create alcohol during fermentation.
Before calculating the ABV, you must get the Original Gravity (OG) of the wort and the Final Gravity (FG) of the finished product. To do this, collect a sample of wort and add to a test flask. Next, drop a brewing hydrometer, read the number below the meniscus (OG), and note it down. Do the same process after fermentation and record the readings (FG).
So, how do you calculate the percentage ABV? This is the process: Subtract the Final Gravity (FG) from the Original Gravity (OG) and multiply the difference by 131.25. Here is the formula: ABV= (OG-FG) * 131.25.
Understanding the Alcohol Content in Beer
The alcohol content in beer (ABV) is the percentage of ethanol found in a beverage. It is the standard measurement used globally to assess the strength of a particular beer. For instance, if your beer contains 5.6%ABV, it means that 5.6% of the total volume is made up of ethanol.
Averagely, most light beers have an ABV of 4.5% to 5.5%. However, there are others with higher alcoholic content, which should be consumed in moderation. For instance, Brewmeister Snake Venom (beer with the highest ABV) has a whopping alcohol content of 67.5%ABV. Such a beer is crafted using specialized ingredients.
Even though most brewers use the alcohol by Volume (ABV) scale to measure the percentage of alcohol in a beer, there are other scales that can help brewers. Some of the scales used include Alcohol by Weight (ABW) and Plato.
Methods for Measuring Alcohol Content
Now that you understand what alcohol by volume means, let us divine in and learn the methods most brewers use to measure beer potency:
Hydrometer Method
The hydrometer method is the most widely used by homebrewers since it is easy to use and the materials (hydrometer and a test flask) are readily available. There are two types of hydrometer: glass and the new digital hydrometer. We will see how both of them work.
The following is how the normal glass hydrometer works:
- Prepare your testing glass by cleaning and ensuring it is dry. You do not want to introduce contaminants into your batch, which could interfere with the flavor of your beer.
- Fill the prepared testing glass with a wort sample.
- Dip the glass hydrometer into the wort sample and record the readings. The reading is called Original Gravity (OG). Ensure you read the number at the bottom of the meniscus to get accurate readings.
- Take the temperature of your sample by adjusting the hydrometer for temperature reading. Most of them are calibrated to 60 degrees Fahrenheit. If the temperature reading is not 60 degrees Fahrenheit, correct the temperature using an online calculator or the chart that came with the hydrometer.
- Add yeast to your wort and leave to ferment until no bubbles appear in the fermentation chamber. This will take around two weeks but sometimes depends on the type of beer you are brewing.
- Take another hydrometer reading after fermentation has stopped and record. This reading is known as Final Gravity (FG).
- Calculate the ABV of your beer using the readings. Find the difference between the first reading(OG) and the second reading (FG) and multiply by 131.25 to get the percentage ABV. Use the formula: ABV= (OG-FG) * 131.25.
- For instance, if your OG is 1.070 and the FG is 1.009, ABV= (1.070-1.009) *131.25. You will get 8.0%ABV.
As mentioned earlier, we have another type of hydrometer (digital hydrometer) that can help you calculate the ABV of your beer. It is more accurate and easier to read. An example of such a hydrometer is EasyDens by Anton Paar. Here is how it works:
- Download the brew meister app for Android or iOS, turn on the device (the hydrometer), and connect using Bluetooth.
- Take a small sample of wort using a syringe (Make sure no bubbles are in the sample) and run it through the unit. It will automatically give you the temperature and specific gravity of the wort. All these will be recorded in the app.
- Repeat the process after fermentation and calculate your beer’s ABV.
Refractometer Method
A Like a hydrometer, refractometer comes in two types, normal and digital. Here is how to use the normal refractometer:
- Calibrate the units by placing a few drops of water on the slide and adjust the scale to zero
- Take a sample of beer wort and place a drop onto the slide, ensuring there are no bubbles.
- Hold it up to the natural light source to get the readings. It has two scales, Brix and SG (Specific Gravity) scale. Use the SG scale to get the readings. Adjust the temperature readings to 86 degrees Fahrenheit to get the correct figures.
- You will see a line marking the split between a white and a blue area. This is the original gravity of the wort.
- Take another reading after the fermentation has stopped and record
- Go to an online calculator, such as Northern Brewer Website, and enter the figures (Original and final readings) for accurate specific gravity. Multiply the SG by 131.25 to get the ABV of your beer.
If you want to know how to measure abv accurately using a refractometer, then you have to go with a digital one. You can go for EasyDens by Anton Paar, which is affordable and easy to use. It also gives accurate figures compared to the normal refractometer.
The device works the same as EasyDens by Anton Paar’s digital hydrometer. If you want to use it, download the brew meister app for Android or iOS and connect via Bluetooth. Drop a wort sample into the device, and you will see the readings on your phone.
Frequently Asked Questions
How Do You Test for Alcohol in a Drink?
The fastest way to test for alcohol in a drink is by using an AlcoScreen. The device is designed to detect even the smallest amount of alcohol in any drink or saliva. It gives you an answer of YES or NO within 2 to 4 minutes of coming into contact with alcohol.
How Do You Label Alcohol Content?
The best way to label alcohol content is by using the abbreviation “vol” for volume and “alc” for alcohol. The words may appear in lower or upper case letters, depending on your preference. After writing the abbreviations, indicate the numerical percentage. For example, you may write something like this, alc 4.5% or vol 5.2%.
Is Beer Bad for the Kidneys?
No, beer is not bad for the kidneys when consumed in moderation. Consuming in moderation means you should not take more than one drink daily if you are a woman. Men, on the other hand, should consume no more than two drinks per day. Excessive beer consumption can interfere with your kidney, hindering them from filtering the blood well.
Conclusion
Mastering the art of measuring the ABV in beer is essential for brewers and enthusiasts alike. Accurate measurements ensure consistent flavor profiles, regulatory compliance, and a deeper appreciation of this complex beverage. Whether employing hydrometers, refractometers, or advanced techniques, precise alcohol measurement elevates the brewing journey and the enjoyment of every sip.