About Grape yeast..

[jo.trader]

Today I finished making my first wine, I mashed 3 kilos of grapes I didn't add sugar or yeast
Just pure grape, when I done bottling i notecied some stuff in the bottom
Is it yeast? If so can I use it for other recipes "I don't mind grape flavor" and dose it have high alcohol tolerance?
Ty.

 

[JohnMc]

Did it ferment? If yes, there is some yeast in there, along with other microbes. (There would be microbes in it regardless, of course, but fermentation increases the population.)

 

[jo.trader]

Did it ferment? If yes, there is some yeast in there, along with other microbes. (There would be microbes in it regardless, of course, but fermentation increases the population.)

its done fermenting

 

[Northern_Brewer]

Is it yeast? If so can I use it for other recipes "I don't mind grape flavor" and dose it have high alcohol tolerance?

It may well be yeast mixed in with other crud.

If it's wild yeast from grapes, then it will probably behave like most wine yeast - which means it should have reasonable alcohol tolerance but will likely have killer factors (so won't play nicely when blended with other yeast), probably won't ferment complex carbohydrates (so will work with the simple sugars in fruit but will give poor attenuation in beer) and will probably give "Belgian" phenolics if fed phenol compounds (present in all grain to some extent, more so in wheat and maize). It won't give "grape flavour".

 

[madscientist451]

Sure, you can use it, but commercial wine yeast is super cheap. If you don't have access to anything else, I'd save it and use it, otherwise, I'd just dump it.

 

[JohnMc]

its done fermenting

Then it's largely yeast. Fermentation selects for yeast, more or less.
There's a French wine, the appellation of which escapes me now, that is fermented just the same way you did yours. If the wine is good, the lees (skins, etc) from the fermentation are put back in the vineyards. This acts as compost and, more importantly, puts good yeast back into the 'wild' at high populations.
It may or may not be good for anything else, only testing can tell.

 

[JohnMc]

PS: testing to find out can cost time and money. If you're into it, sure, otherwise, tested yeast are cheap.

 

[jo.trader]

Thank u all for the replies, I'll test with a store bought juice for fun

 

[RPh_Guy]

If it's wild yeast from grapes, then it will [...] likely have killer factors

Do you have a source for this info?
If not, why would you assume the dominant strain(s) produce competitive factor?

 

[Northern_Brewer]

Because the vast majority of wine yeasts do produce killer factors.

It's one way the dominant strain...becomes dominant.

 

[RPh_Guy]

You might be right, but I don't feel comfortable making that extrapolation (to wild yeast from commercial yeast) without actual data.

I can find hardly any data regarding wild/"spontaneous" fermentations. It's hard to even say what the likelihood is that the dominant strain is Saccharomyces. Other genera can have strong fermentation kinetics as well.