What is the wild yeast ?

So called "natural" fermentations (i.e., no added yeast) will work, and many swear by them. OTOH, I consider it a needless risk to rely on the wild yeast to reliably accomplish a clean fermentation. Yeast is cheap but your time is dear, so why take unnecessary chances?

It is not necessary or even desirable to wash grapes prior to fermentation. Whatever dirt, etc. is on them will end up in the discarded lees after the first racking. Just be sure to sulfite the wine after it finishes fermentation, and top up the containers to keep air away and you should be OK. BTW, don't let the wine sit on its lees for too long prior to the first racking or you may end up with a nasty surprise (H2S).

Tom S

Aaaaah, now i get it... the extra stuff is the terroir in wines that I keep hearing about!!!!

OTOH it doesn't HURT to wash the grapes... LOL (tho not commercially economical).

That being said, a wet grape is a grape just waiting to grow mold. Good idea if you are going to wash them, sulfite them immediately after the wash step (i.e. the final dip could be in 20-50ppm free SO2 potassium metabisulfite solution). The meta residue will get diluted to next to nothing when you crush the grapes.

Gene

Tom S wrote:

Actually, there _is_ a downside to washing grapes (aside from the mold possibilities), and that's dilution. You'd be adding water to the must/juice, and unless you've got some fruit that's a touch overripe I wouldn't recommend washing the grapes.

Tom S

Yep, you're right again, Tom. Dilution would be significant if going straight from wash to destem/press.

My 18" Patton fan and wire mesh drying racks solve the dilution problem, and the grapes are nice and cool the next morning when I destem/press. Of course, I'm only doing a few hundred pounds batch size. Hard to imagine doing that for a half ton of grapes or more. And even harder to imagine doing it anywhere an evaporative cooler isn't effective.

My rationale for washing the grapes is to lessen the 'earthy' flavors and proteins which (admittedly minor) would otherwise be extracted during fermentation (from the humus/dust/bird droppings on my often very dusty, second growth harvest). Last year they even had fertilizer dust residue, cuz the vineyard management folks started soil amendment (for this year) before I harvested.

I find the washing/drying a small price to pay for getting free grapes. And the wine from them is pretty good, despite my anal retentiveness.

Anyone else as obsessive as me?

Gene

Just my take on this:

In many areas of Europe where grapes have been grown for hundreds, if not thousands of years, natural yeast has developed in the area that is good wine yeast. After all, the wine was made in the same area and the yeast that will ferment good high alcohol wine would multiply best in the wine. The must is then spread back to the soil so you are culturing yeast between the winery and the vineyard and end up with good wine yeast dominating. It is not actually wild yeast anymore. Now if you get your grapes from one of these areas, you have a real good chance of having a good ferment from the yeast on the grape skins.

If you are getting your grapes from some area in the US where grapes have not been grown for hundreds of years and where the wine may not be made in the vineyard and the pumice may not be spread back in the field ... it may be a bit more iffy. But it will probably still work.

Then again, good wine yeast is cheap. Grapes and time are expensive. Why take chances. I buy yeast.

Ray

Wild yeast is simply a yeast that is not from a package. It is recommended to use a packaged yeast for your wine, since it gives you some control over the type of yeast. The wild yeast that ends up taking hold of your fermentation process may be most suitable for breads, which is not what you want in your expensive juice. (It could also be suitable for wine - but you won't know what you've got fermenting until it's all over, so most people don't think it's worth the risk).

A (crushed) campden tablet for each gallon of must when you first start your process should knock out any wild yeasts. 12-24 hours after adding the campden, you should add the yeast of your choice.

Vinegar can result if you allow oxygen to get into your fermented must. You want oxygen during the first week, but after that you don't. That's when you should rack your must from the bucket to a carboy that's been fitted with an airlock.

Woods