Homemade Wine: Fermentation Explained

Fermentation of homemade wine is one of the first principles you must understand when taking up this hobby.

Fermentation is the process by which the 'must' (the primary, soon-to-be-wine mixture) turns into wine. Oddly enough, even though the process is vital to our success, we have little to no control over it.

Our primary concern is in the preparation before fermentation. To make homemade wine we first prepare a mixture that contains the substances that eventually lend a pleasing flavor to what eventually becomes a finished wine.

To kick start the fermentation process we start with yeast. Yeast is a living organism that feeds on sugar. Back in the old days, standard kitchen or bread yeast was used. Thankfully however, in more recent years we have upgraded our initial ingredients to a more specialized wine yeast. Most wine yeasts are imports, or derivatives of imported yeast from countries known for their great wines.

Make no mistake, you can still use bread yeast in a pinch - but if you have the choice, hold off until you can get your mitts on some high quality Wine yeast. This isn't just for finery - wine yeast produces a wine that is higher in overall alcohol content.

As I said, yeast feeds on sugar. And again, you can certainly use regular granulated white sugar for the job, but if you want to step up your wine to something a little more elite, opt for invert sugar.

The Fermentation Process in Action

Yeast, although a living organism, is sold in a dormant state. You can buy wine yeast as a pellet or cake, as well as in a power packet.

Preparing yeast for the must often involves a starter batch. Take a small glass bottle, some sterilized water, and some sugar (actual portions will be listed on the back of your yeast packet - each one differs) and boil.

Once your sugared water has cooled to room temperature, add the yeast, cap the bottle (saran wrap will do) and place the bottle into a warm place for a day or two (again, each yeast type varies).

When you first add yeast and sugar to your primary wine mixture you'll likely see a bubbling or frothing on the top of the liquid. That, is fermentation - or at least the start of it. The yeast is 'eating' and growing throughout - turning the sweet into alcohol.

This can go on for a very long time. Our job is to ensure that it doesn't take much more than 3 months so we can bottle and enjoy our homemade wine quicker. We'll discuss ways to accomplish this later in the article.

When the yeast has finally died out, eaten all the sugar and eventually killed itself by the alcohol content it created, fermentation is over. If someone tells you to let your wine sit longer than this to increase the alcohol level, don't believe them. It's over when it's over.

So let's talk about ensuring this process goes quickly and efficiently. One way to ensure the yeast is operating at optimum speed is to keep the wine must (remember the must is the primary mixture before it turns to wine) warm. The optimum temperature is between 65 and 70 degrees Farenheit.

This doesn't has to be exact and you certainly don't need to take the wine's temperature - just be aware of the room temperature in your house (or where ever you store your wine) and adjust accordingly. In our drafty farmhouse, on cold winter nights, I often just moved my wine in progress closer to the cook stove.

Fermenting Homemade Wine Faster

Apart from the warmth of your must, you might also like to add yeast nutrients - found in most wine supply shops and online retailers) - to the mix. These nutrients help the yeast to keep reproducing, increasing the alcohol content, until it's time has come.

Nutrients are most often available in a powder form.

Simply premix some (follow package directions) with some of your must and add it back in.

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