How to Use a Hydrometer
One of the most crucial tests in making alcoholic beverages is knowing how to use a hydrometer. A hydrometer measures the Specific Gravity (S.G.) of Sugar in your must or wort. It is important to take a hydrometer reading BEFORE you add yeast to any wine, beer, mead or cider you plan to turn into alcohol. This reading is called the Original Gravity (O.G.) after your beverage has fermented you will take a Final Gravity (F.G) reading. Read on how to measure and find your % ABV (Alcohol by Volume).
It’s easy to measure, just follow these steps!
1. Clean and sanitize your hydrometer.
2. Put a sample of your beverage into a test jar ensuring there is enough for the hydrometer to float freely.
You may also carefully place the hydrometer directly into the primary fermenter
3. Place the hydrometer in middle of jar. It may naturally want to stick to the side of the test jar, so give it a gentle tap to encourage it to move towards the middle of the jar. If you’re testing in the primary fermenter, place the hydrometer near the center and clear away any surrounding bubbles to make it easier to read.
4. With the jar or fermenter on a flat surface try to get your eyes as level as possible with the hydrometer. Note the reading at the bottom of the curve of the liquid surrounding the hydrometer. This curve is called the meniscus and the most accurate reading is given at the bottom. This is your Original Gravity (O.G.) write it down to determine your ABV in a few weeks.
5. After a few weeks have passed and your wine, beer, mead or cider has fermented you will take a Final Gravity (F.G) reading. Repeat Steps 1-4 to take another reading. This time the hydrometer will be much lower due to the absence of sugar and the increase of alcohol in your beverage. Likewise, you may choose to take a reading the first few days after you have pitched the yeast if you think your beverage is not fermenting. As long as the hydrometer is reading a lower number than the O.G., your yeast is working and your beverage is fermenting.
6. Finally, to determine your beverage's % of ABV; subtract the Final Gravity from the Original Gravity and multiply the result by 131.25 to determine the ABV of your product.
