When can I add pectinase?

It will help... most add in the beginning, however you can add even after transfer to your secondary.

Mix it with a bit of water, then stir it into your wine -- good luck with your wine!

Steve

doesn't breaking down pectin result in methanol?

There are minute amounts of methanol in almost any wine, I do not believe pectinase to be a serious contributor. The end result of using pectinase is a wine that does not cloud (chill haze) when refrigerated.

Steve

Yep, but that is going to happen wheather you ad pectinase or not. The yeast will break down some of the pectin themselves. That is why you need to age wine. During aging alcohols combine with acids to form esters (compounds that give wine fruitty aromas). This is why (along with slow oxidation of tannins and other compounds) wines "soften" with age, the harsh edges round off.

Pectin is a huge branched carbohydrate that is important for plant cell wall integrity, it exists in many forms depending on tissue, species etc. Pectin is modified by esterification (this changes the crosslinking between branches) and the enzyme pectin methylesterase removes these modifications and is what releases the methanol. It is my understanding that many of the pectic enzymes that are sold to us are actually cocktails of enzymes that will attack different parts of the pectin molecules. Since there are many different linkages in the molecule it takes many different enzymes to put it together or take it apart.

-Alex P