Using Bottled Water When Making Wine
Using bottled water when making your wine is fine, and in some cases preferred, depending upon what's in your tap water. But, not all bottled waters are the same. Some bottled waters have been distilled and that's a bad thing for winemakers. When choosing bottled water for wine making be sure that it is labeled as spring water, mineral water or some kind of drinking water and not labeled as distilled water.
Using Distilled Water When Making Wine
Using distilled water can cause big problems for the unsuspecting winemaker. There are two reasons for this. The first being distilled water has had all of the excess or "free" oxygen removed from it. The second reason is that distilled water has no minerals either. Both of these conditions are direct results of the distilling process and both conditions have inhibiting effects on a fermentation.
During the primary fermentation the wine yeast need an ample supply of oxygen in the must to allow them to freely reproduce themselves. The yeast has the monumental task of multiplying themselves to around 100 to 150 times during the primary fermentation. If the yeast are not given enough oxygen to multiply successfully, then the result will be a sluggish fermentation that can drag out for several additional weeks.
Having no minerals in the water affects the fermentation in a negative way as well. Minerals are a significant portion of the nutritional meal the is required by the yeast to perform at their best. Different minerals effect the wine yeast in different ways, but in general, minerals increase the yeast's ability to metabolize or consume sugar. Without a supply of minerals you have yeast that consume sugar at a slower pace.