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Using a HydrometerUpdated a year ago

Most of the wine/cider/mead you’ll make with Brewsy is 10% to 15% ABV (alcohol by volume). And many people decide to measure ABV just by taste!

However, if you want to know exactly how boozy your brewsy is, you can use a tool called a hydrometer. It will let you find out the exact ABV!

A hydrometer works because of a remarkable principle: we know just how well something will float based on how much sugar is dissolved in a liquid. There's two things we know about hydrometers:

Thing 1: When there's a lot of sugar dissolved in a liquid, a hydrometer will float really well.

Thing 2: When alcoholic fermentation has occurred and your yeast has eaten some of that sugar, your hydrometer will float less well.

Here's the trick to how it can tell us the amount of alcohol in our drink:

We can see just how well your hydrometer floats before fermentation when there's a lot of sugar. Then, we can see how less well your hydrometer floats after fermentation when there's much less sugar. The change in how well your hydrometer floats tells us just how much sugar was eaten by your yeast. You’ll take 2 samples — one at the very beginning, before you add your Brewsy bag and one at the end of fermentation (after about 5 days, or when your Brewsy tastes dry enough for your liking).

This sample was taken at the end of fermentation. It reads 1.000, which means there is no sugar left for the yeast to eat. We'll discuss how to read what that means soon.

Here’s how to use your hydrometer:

1. Add all the sugar to your juice, and wait for it to dissolve. Then, fill the graduated cylinder that came with your hydrometer up to the top with juice.

2. Place your hydrometer in the juice sample, and give it a spin, so that no carbonation bubbles are sticking to it.

3. Let it bobble up and down until it starts to float without moving.

Take the first reading:

- There are a lot of different columns on your hydrometer. You’re going to want to look at the column that says “Sp. Gr.” (short for specific gravity) at the top. The first number at the very top of this column says 0.990, and the second says 1.000.

- Your hydrometer is likely floating at about 1.100. Here's a bit of information on how to take the exact reading:

If you're starting at 1.100, move down further into the blue section. The lines move down in increments of +0.002, so the next line would read 1.102, the next would read 1.104, the next would read 1.106, then 1.108, and then 1.110.

Here's a photo with some example readings!

Observe which number your hydrometer is floating at (where the surface area of your wine intersects with the marking) and write it down for later.

Then, let your brew ferment!


After it’s fermented for at least 5 days, give it a taste-test to see if it’s dry enough for your liking. Then, follow these steps:

1. Take another hydrometer reading with the steps from above. It will sink more and might say "1.000" on one side and "0%" on the other. Don't worry — this actually means that your wine has a LOT of alcohol in it, not 0%!


Here's what your hydrometer will look like towards the end of fermentation. One side will say 1.000, and the other side might say 0%.

2. Head to our hydrometer calculator.

Plug in your first reading (called the original gravity) and your second reading (the final gravity). The calculator will take the two readings and determine your ABV.

It may be a little bit lower than 15%. Wine made with Brewsy is usually around 10% to 15% ABV, but keep in mind that 15% ABV is very strong for most wine, and sometimes it will taste better on the less alcoholic side!

Still, if the second reading you took was more than 1.000, there is more sugar in your wine that can be converted into alcohol. (That's okay, but maybe you want to let it go longer to try and get it more boozy!)

Try to get it warmer to speed the yeast up. After a couple more days, take another reading.
If it is at your desired ABV, it is ready to cold crash! You can move your brew to your fridge.

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