What is the chemical equation for wine fermentation?
Generally there are two types of fermentation in biochemical processes:


homolactic fermentation
alcoholic fermentation


Both these processes occur under anaerobic conditions to replenish NAD+ 
by the reduction of pyruvate in an extension of the glycolytic pathway.


The overall reaction in muscles is:
$$\ce{Glucose + 2ADP + 2Pi -&gt; 2 lactate + 2ATP + 2H2O + 2H^+}$$
For alcoholic fermentation:

Glucose is first converted to pyruvate by glycolysis, and the pyruvate is converted to ethanol and $\ce{CO2}$ in a two step process:


Note: For the second one we just started with pyruvate (to show mechanism and enzymes involved)Otherwise, for alcoholic fermentation, the net reaction is:

$$\ce{Glucose + 2ADP +2Pi + 2H+ -&gt; 2CO2 + 2C2H5OH +2ATP +2H2O}$$


Both homolactic and alcoholic fermentation have the same function: the anaerobic regeneration of NAD+ for continued glycolysis. Their main difference is in their metabolic products

Having said that lets go back to experimental wine fermentation, it is essentially alcoholic fermentation (2).

Enzymes in yeast (zymase a mixture of enzymes) and  cozymase  a mixture of cofactors-coenzymes such as NAD+ , ATP, and ADP, as well as metal ions) help carry out the fermentation reactions.