During wine fermentation, is it a good or a bad thing to shake your must?
February 23, 2010 by Instant Wine
Filed under Answers
Question by sdfdsf434: During wine fermentation, is it a good or a bad thing to shake your must?
I have wine fermenting right now. I have tried googling and can only find vague guides that say “some people advise shaking during fermentation” or some things to that effect. Is it good to shake the wine during fermentation or is it a bad thing? Does anybody know? I don’t want to botch my batch! 
Best answer:
Answer by TorxBit
Mostly it does nothing to it other then suspend some of the trub in the wine. As long as you do not add more air to it, it makes no difference.
Give your answer to this question below!
It is good at the start, getting the yeast to reproduce rapidly. By the second day, you want little or no oxygen in the must, so you do not disturb it at all. That’s when the yeast settles down to making alcohol for you.
You have not provided enough information for an accurate pertinent answer to be provided. Still I will try. Oxygen is often added at the beginning of yeast fermentations. The oxygen aids in yeast respiration and leads to budding or increased cell count. Oxygen is also used in yeast cell development and so it vital to the yeast in that respect. By disbursing the yeast throughout, as apposed to settling, the tank sugar is exposed to the yeast for its purposes of fermentation. Later and after the fermentation has completed the winemaker (you) wants to minimize the dissolved oxygen in the wine because it may lend to haze, spoilage bacteria growth, and/or off-flavors.
:…shake your must?”
If by shaking you mean to mix, then it is need in red wines. Red wines get their color from extraction of pigment in the skins of the grape berries. Once the grapes have been crushed and the fermentation has begun several methods are employed to accomplish this. One of the modern methods is to pump the fermenting juice from bottom to top of the vessel. During this process the juice is spread across the cap extracting the pigments. An older/traditional method used is called a “punchdown.” I had done this method making Pinot Noir while on a summer internship in college. A tool is used to manually push “punch” the cap down into fermenting juice extracting the pigments. To a certain degree the pigments are more soluble in the increasingly more alcoholic juice. This is a factor of both the ethanol and pH of the juice/wine. A benefit of this punch-down is providing more oxygen to the yeast and lengthening and strengthening the fermentation. Another thing shaking or mixing the yeast does is spread it.