3. The purpose of the Potassium metabitsulfite is to kill off any wild yeast, bacteria, etc. in your must. This can be eliminated by simply heating your must to a temperature of 170degrees and letting just simmer on your stovetop for 30 minutes. Do not boil the must as to much heat will set the Pectin in the fruit making fermentation more difficult.
"Sulfur dioxide has three major functions in winemaking: to control undesirable organisms, to inhibit the browning enzymes, and to serve as an antioxidant"
University of California Press.
Simmering certain fruits can contribute to hazes in wine (which are often hard to clear), and will alter the taste of the finished product, often with a loss of the fruit taste.
Can you use bakers yeast to make wine? Of course, but every yeast works on the fruit a little different, yielding different taste and different alcohol levels. Wine makeing yeast is very in-expensive and the finished product is much more repeatable and predictable. Junk in, junk out. Good wine takes time and a quality yeast, Why waste your time, and fruit, using a poor quality yeast.
Some people like to ferment just the juice, and nothing but the juice. Sadly, not all fruits have the same amounts of nutrient for a good fermentation, and will often "stick" (stop fermenting before the sugar is converted to alcohol). I add a nutrient to many of the fruits I know are low and they NEVER stick!
I have found the major cause of a sticking fermentation to be the addition of to much sugar and to much water. I like to use as pure a juice as I can, even tho this will mean a lesser quantity of wine. I also like to add my sugars slowly, it the recipie calls for 4lbs of sugar, I will only add 2 lbs in the primary. Then another pound when racked into the carbouy, and then the other pound at the next racking. I fact, I have quit using sugar recommendations suggested in recipies completely. I just tastetest everytime I rack and add sugar according to my taste.
Not true either. Winemakers do not add sugar incrementally. Sugar in the grape is (almost always) at the correct level prior to fermentation. Sometimes a winemaker (grape) will add another juice higher in sugar if his primary must is low. For the wine industry, it would be impractical and expensive to add sugar in this way.
If you use a hydrometer correctly, there should be no need to adjust sugar later in the fermentation - this could actually cause a wine to stick. Sugar added later may cause a wine to stick, then later, after bottling the wine may start to re-ferment and you end up with an exploded bottle (or many). This is a very dangerous thing to do. Sweetening a wine can best be done using a non fermentable sugar (like Splenda)
OR by using Sorbitol (potassium sorbate) or other product to prevent refermentation. Also, it's much more difficult to determine the alcohol content if sugar is added during fermentation.
All my information comes from these sources:
Amerine and Singleton, Wine, an introduction for Americans. University of California Press.
"Winemaking Basics" C.S. Ough, DSc, MS (Dr. Ough was a faculty member of the Department of Viticulture and Enology at the University of Califonia at Davis for 41 years.
"The Complete Handbook of Winemaking" - the American Wine Society
(just to name a few; I have a lot more books in the library
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