Do You Really Need Wine Making Yeast to Make Wine?


Someone emailed me the other day and told me of a wine recipe that she found in mothers things that did not require any wine making yeast. She wanted to know if yeast was important and needed for wine since a friend of hers said it was but didn’t know why.

I wrote her back and told her quite easily that without wine making yeast you have no wine, only grape juice. It is when the grapes meet the yeast that the process of fermentation happens and without that process you will not have alcohol.

I went on to explain that the grapes have sugar in them and when the sugar is gobbled up by the one celled living fungi, yeast, that alcohol is made.

It was in1859 that Louis Pasteur discovered that a single cell organism was responsible for the conversion of sugars into alcohol and carbon dioxide. The Egyptian’s were the earliest recorded users of yeasts.

Yeast is a fungus and is very small, so small it takes almost 20 billion of them to make up one gram of yeast. How amazing is that? For you chemistry majors the chemical reaction that happens is C6h32O6 + yeast = 2C2H5OH + 2CO2. There is much commercially grown yeast that is packaged in small amounts for home wine makers to be able to afford and use. They make it by using a known strain of yeast and adding it to sugars that help it multiply rapidly. They then harvest the yeast. Lately it seems the most popular kind of preserving yeast is to then freeze dry it and keep it in the refrigerator until needed. To use the wine making yeast then all you have to do is reconstitute or rehydrate it with water at 40C then letting it sit for a half hour. It is then added to the wine must to begin fermentation. There are many kinds of yeast products, it is important to only use wine yeast and not try to use say bread yeast as it just will not work. Yeast does occur naturally in the wild and settles on grapes, but they are killed before fermentation. If left on the grapes and allowed to be part of the wine they would give unpredictable results and some really different and even bad smelling wine. It is the wine maker that decides what results he wants in his wine even before the fermentation process is started So you can see how important it is to wine to have wine making yeast added. Without it you really do not have wine for the fermentation process would never be allowed to begin. Choose wisely as the type of yeast you do add can change the flavor of your wine.


Source by Kacy Waters