Of all the pieces of homemade wine equipment in which you can invest, the gravity hydrometer ranks as one of the highest as being money well spent. Not only can the hydrometer tell you how much alcohol your wine is going to have, it can tell you how far along your fermentation has progressed and even whether or not the fermentation has completed.
Yet, many beginning winemakers do not use a hydrometer. I can see their eyes glaze over as I begin to explain to them how the hydrometer works and its applications. They think it’s over-complicating their newly-found hobby and want nothing to do with such scientific equipment.
In reality, the hydrometer simplifies the winemaker’s life for all the reasons mentioned earlier. Think of the hydrometer as a compass for navigating your fermentation. It will tell you where your fermentation stands and in what direction it is headed.
Taking a hydrometer reading is diseptively quick and easy. In fact, it’s easier than using a thermometer. All you are trying to do is see how high or low the hydrometer is floating in your wine. You take a reading by seeing where the surface of the wine is crossing the scales on the hydrometer.
It’s that simple: make sure the hydrometer is floating, and take a reading. If the hydrometer is touching bottom, then you either need more wine or you need to use a taller container. For example, a gallon glass carboy is typically not tall enough to take a reading with most hydrometers.
We have hydrometer test jars, also known as H-jars to help make this process even easier than it already is. They are basically slender tubes or vials with a sturdy base. They are designed specifically for taking hydrometer readings. And, they’re not that expensive when compared to the wine is will be helping you to make.
Here are a couple of articles listed on our website that cover this topic in a little more detail: Getting To Know Your Hydrometer and Hydrometer Scales And What They Mean. You may also want to get the book, First Steps In Winemaking, which has a great section on using a gravity hydrometer.
Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.