Alcoholic fermentation is a biological process in which sugars are converted by yeast into alcohol and carbon dioxide. For this process, it is important to note that your yeast will be competing for resources with both wild yeast and bacteria. As such, it is important that you sterilize your equipment and add a sufficient amount of yeast. Most yeast packets are meant for fermenting around 5 gallons. In light of this, you will need to add more yeast if you are using a larger fermentation vessel.
Much of the flavor of your alcohol is owed to the yeast. As such, it’s important to choose your yeast wisely. Turbo yeast is popular with many new distillers. However, there are many other and far superior types of yeast out there. Turbo yeast is commonly used to create a neutral spirits that tend to lack in flavor. If you’re trying to make a spirits such as whisky, brandy, or rum, you will want to use a yeast strand that will complement your ingredients and give you the flavor profile that you desire.
There are two distinct phases in the fermentation process, which are the primary phase and the secondary phase. After the first hour or so, the yeast begins to reproduce rapidly and the number of yeast cells increases exponentially. The primary fermentation is the phase in which most of the alcohol is produced. It is also during this phase that the yeast replicates and grows. During the secondary fermentation the yeasts growth rate will significantly slow. This will be evident in the decline in bubbles that are produced during the primary fermentation. It is during the second fermentation that the yeast will sink to the bottom of your fermentation vessel.
There are many different factors that can contribute to either a poor or stalled fermentation. These include a lack of nutrients, sugar, temperature, and oxygen. Your yeast will go dormant if the temperature of your wash is to low, and will die if the temperature of your wash is too high. You may also want to make sure that your wash isn’t too acidic. You wash’s pH should be between 3.6 and 6. However, this isn’t a very common issue. Before adding your yeast you will want to oxygenate your wash by giving it a good stir.
Another common issue is involved with fermentation is having either too much or too little sugar. If you don’t have enough sugar, your yeast won’t begin to replicate or produce alcohol. However, if you have too much sugar, your yeast can become stressed and produce off flavors. If you use too much sugar you can add water to dilute your wash down to a more hospitable level. Some home distillers will add a little sugar after a couple of days in order to reinvigorate their yeast and to bring up the overall alcohol content.
If your water is lacking in nutrients you may find it advantageous to add minerals such as gypsum. Your local home brew supply shop should have everything you need. They can also be a great resource for information regarding fermentation.