The Secret to Understanding Hydrometers

Posted | By:  

How many of you struggle to read a hydrometer? How many batches of your home wine brewing have had to have ingredients added in order to fix them because of not being able to understand your hydrometer readings? Have you had any wine which you have had to throw out?

Well, help is here and it comes in the guise of easy-to-use instructions for your hydrometer.

Using Your Hydrometer
  • Always make sure that your hydrometer has been sanitized this sanitization procedure also applies to the wine thief and the jar in which you will test your wine.
  • Make sure your jar is on a flat surface and take a clean sample of wine with your wine thief.
  • You should make sure that your test jar is filled within enough wine to make it approximately 80% full this should help ensure that the hydrometer floats properly
  • As you lower the hydrometer into the test jar, spin it so that the bubbles of your wine don't stick to the bottom of the hydrometer as this can affect your readings.

Now look directly at your wine in the test jar make sure you are level to the top of the wine's curved surface this curved level should look a bit like a bowl. Take your reading from this point.

The type of wine you are making as part of your home wine brewing process will dictate the hydrometer level you should be aiming for.

The first thing you should remember is that you need to calibrate your hydrometer each and every time you use it in order to get the best results. The best way of doing this is to keep a jar of water in the same room (and nearby, if you can) to your fermentation vessel. This will allow the wine and the water to come to the same temperature.

Next, you need to take a hydrometer reading of your water only it should around 1000sg (i.e. a specific gravity level of 1000, or 1.000, depending on the hydrometer). If it comes to, say, 997 (or 0.997), then when you take a reading of your wine, you will need to add 3 (or 0.003) to it. If the reading on your water is, conversely, 1002 (or 1.002), then you would need to subtract 2 (or 0.002) from your wine reading. See, home wine brewing is easy when you have the right information.

The reasons for testing your hydrometer in water each and every time you want to test your wine is as follows:

  • With some hydrometers, especially ones which come from less than reputable suppliers, may have used a sub-standard type of glue this means that the scale may come loose from the hydrometer itself.
  • It also means that some of these same hydrometers may not have had their scales glued in exactly the right location. Testing with water allows you to compensate for that.
  • Thirdly, temperatures in a room can change which can then affect your hydrometer readings. Testing with water which is at exactly the same temperature as your wine allows for accurate compensation.

The next time your wine yeast stops working, you now have the knowledge to fix it. Even if this particular wine in your home wine brewing batch does not come out perfectly, your fact-finding arsenal will be well and truly armed for the next batch.

Cynthia Cosco is the founder of Passaggio Wines and is an award-winning winemaker educated in Napa. Through she offers 12 month support on email and Skype to a book on making wine at home. To get a free preview of the book click here.

Posted in
  Email   Print
November 27, 2013  •  11:13 PM
Can you tell me what does it mean if the hydrometer does not float?