How to use a Triple Scale Wine and Beer Hydrometer

Bev
Jul 10
5 min read

Updated: Aug 28

If you have acquired a Triple Scale Hydrometer or a Kit containing one and are wondering where to begin, this is all about how to use a Triple Scale Wine and Beer Hydrometer.

How to use a Triple Scale Wine and Beer Hydrometer. — *This is a reader-supported site which means* *means that if you purchase a product or service using my one of my links, I receive a small commission at no cost to you.* And this is a Triple Scale Wine and Beer Hydrometer.

Produced by hydrometer production market-leader Stevenson-Reeves, this easy-to-read triple scale hydrometer is 23cm long and has 3 scales for measurement.

The coloured bands on the hydrometer indicate the readings you would expect to have at the beginning of the process when you make wine, cider, beer and mead, and at the end. There is also an indicator for sweet, medium and dry wines.

You will find an instruction leaflet inside the plastic tube, wrapped around the hydrometer. The following guidance is designed to supplement that leaflet, taking into account frequently asked questions about hydrometer use.

The 4 Main Purposes of a Wine and Beer Hydrometer

Different types of hydrometers are used across many industries. We are focusing here on a Triple Scale Hydrometer designed specifically for homebrewing of Beer, Wine, Cider and Mead.

The 4 main purposes of a wine and beer hydrometer are:

to calculate the final alcohol content of your homebrew, so long as you took a reading at the beginning as well as at the end
to keep a check on fermentation to know when it has completely stopped. This is one of the most helpful things a hydrometer can do, because you’ll then know your wine, cider or mead is unlikely to restart fermenting again later in a glass bottle (think 'exploding bottles' which you definitely don't want)
To find out how much natural sugar is in your original juice
To work out how much sugar you need to add to produce a drink with the alcohol content you want

How to use a Triple Scale Wine and Beer Hydrometer.

I was put off hydrometers for years because it all sounded so complicated. However I now know that it is harder to explain than it is to do.

The hydrometer will come packed in a strong, clear plastic tube along with an instruction leaflet. The hydrometer itself is made of glass. Regrettably I can confirm how easy it is to break a glass hydrometer, so be careful when you're handling it.

As well as being designed as a storage tube for the hydrometer when not in use, the plastic tube can also be used as a trial jar. A trial jar is simply the vessel you put a sample of your homebrew into, to test it. You could use a number of things for this purpose, but the hydrometer fits well into the tube which is why many people use it this way.

Using a Triple Scale Wine and Beer Hydrometer. — Adding a sample of homemade mead to a trial jar (also known as the storage tube for the hydrometer)

So here are the steps:

Sterilise the hydrometer and the storage/trial jar (not necessary if you don’t intend to return the sample back into the demijohn or bucket).
Add the liquid you want to measure to the trial jar so that, when you add the hydrometer to the liquid, it will float without overflowing.
Gently lower the hydrometer into the liquid.
Spin the stem of the hydrometer (the thin end) between your thumb and forefinger before taking the reading. You are doing this so that the effect of air bubbles on the reading is minimised. When the hydrometer stops moving, take your reading at the point where the underside of the surface of the liquid meets the scale.The reading in this example is 1.000 (not 0.9998)
Compare your reading with a chart.
You can then use a table to work out how much sugar to add to get the alcohol content you’re hoping for, if that’s what you’re looking to do.

As your homebrew ferments, the sugar contained in the must at the beginning turns to alcohol. If you know how much sugar there was in the liquid at the beginning and you know how much is left at the end, you can calculate your final drink's alcohol content.

The more sugar there is, the thicker the liquid, so the greater its gravity will be. A hydrometer measures how well the glass instrument, i.e. the hydrometer, is supported in the liquid at different stages of the cider making process. So a hydrometer doesn’t physically do anything at all. No mercury rises or falls. It simply sits in whatever liquid you are measuring, and you take a reading.

Water always has a gravity of 1.000. So in water, the hydrometer will float with the surface of the water level at the 1.000 mark. Any liquid containing sugar will have a higher gravity, so the hydrometer will rise in the liquid giving a reading higher than 1.000. However alcohol is less dense than water, so a hydrometer sitting in a liquid containing alcohol will sink below 1.000.

How to use Hydrometer Tables and Calculating Alcohol Content

If you have taken a reading at the beginning (opening reading) and then again at the end (final reading), you’re ready to calculate the alcohol content.

The calculation for calculating Alcohol Content is:

Opening Reading - Final Reading x 133* = approximate alcohol content.

So for example:

Opening reading 1.085, final reading 0.995.

1.085 - 0.995 = 0.090

x 133 = 11.97 according to the table, or approximately 12% abv (alcohol by volume).

*133 is the number I use for the calculation. You may see slightly different numbers used, like 131 or 135. The calculation gives you an approximate alcohol content anyway, so which of these you choose to use isn’t critical. You will also see people advising you add the two readings together and divide by 0.0074 which is the same calculation.

Here are the tables for when you get to that stage. Note that, as mentioned above, water has a specific gravity of 1.000 which is the first line in the table:

Tables for calculating alcohol content using a Triple Scale Wine and Beer Hydrometer. — Hydrometer tables used to work out the approximate alcohol content of homemade wine, cider and mead

Do I have to use a Hydrometer in Homebrewing?

No you absolutely don’t. Beginners can put off by hydrometers as it can all sound a bit complicated. I know I was and, as a consequence of that, I didn't use one for years. And if you have a hydrometer and you’re unsure about it, that can be a barrier to getting started.

The reality is that if you have bought a kit with a hydrometer included, there is no law to say you have to use it the first time around. Put it somewhere safe, find a simple recipe that doesn’t even mention hydrometers and get going!

Using a Hydrometer - Final Thoughts

A hydrometer can be a really useful tool. I mostly use one for determining whether my fermentation has stopped by taking a reading 3 days in a row. If the reading stays the same and there has been no bubbling action in my brew for days, the chances are that means fermentation has finished and it is safe to bottle. You can use one to measure alcohol content as well which is easier to do than it is to explain, but it is absolutely not essential to use a hydrometer at all and many homebrewers never do.