The published ABV of our beer kits can only ever be an estimate as it will vary slightly according to the precise temperature of the mash, the length of the boil and the temperature of the fermentation (among other factors). If you are interested in knowing the exact ABV of your beer you will need a hydrometer.
A hydrometer works by enabling you to measure the density of the beer both before and after fermentation. The more sugar left in the beer the more dense the beer will be. As the yeast converts the sugar to alcohol the beer becomes less dense. By comparing the density before and after fermentation you can calculate the exact ABV. Full instruction for using the hydrometer are given below.
NB: You will also need to purchase a Trial Jar to use the hydrometer (unless you already have one).
How to use a Triple Scale Hydrometer
1. Clean and sanitise a ladle, small cup or jug
2. Place the hydrometer in the trial jar.
3. Use the a ladle, small cup or jug to draw off sufficient beer to float the hydrometer in its jar.
3. Spin and tap the hydrometer to ensure that there are no air bubbles attached to its base or sides
5. Note the level at which the hydrometer emerges from the liquid. The surface of the liquid will be a concave shape called the meniscus. Take the reading from eye level at the bottom of the meniscus.
Apply the following calculation to the two readings:
ABV = (OG – FG) * 131.25
Or, simply visit this page and enter your figures there.