Will wine yeast overtake spontaneous ferment?

[d v]

I recently purchased 6 gallons of wine must to dive into proper winemaking (I've worked a lot with mead and fruitwines, but never grape wines). Brought it home, added the proper number of campden tablets to kill any wild yeasts that might be present, and waited 24 hours both to let the must come to room temp and to pitch my wine yeast.

Unfortunately, it seems like the campden tablets did not do the trick. I went to pitch my yeast only to find that a wild ferment had already begun and foaming. My question here is, will the wine yeast be able to overtake it or will the wild yeast stay dominant now that it has taken hold? For reference, the wine yeast I've used is 10 grams of Lalvin BM4x4, rehydrated with Go-Ferm. Haven't had this issue with any of the meads or fruit wines I've done in the past, so I'm at a loss as to whether or not BM4x4 will take hold.

 

[sour_grapes]

My money is on the proposition that a wine yeast will be dominant. Let me explain.

Where did you get the "6 gallons of wine must"? It is common for some suppliers to add yeast to bucket. Is it possible yours did? Also, if not, the grapes may not have had "wild yeasts," exactly. The grapes were more than likely from an extablished winegrowing area, and the yeast on the fruit is probably dominated by wine yeasts. There is probably a good reason that the Campden tablets did not deter fermentation.

 

[winemaker81]

I agree with @sour_grapes, commercial yeasts are designed to dominate over wild yeasts. Paul's comment regarding the "wild" yeast not being a truly wild yeast makes sense, depending on where you are and how long the vineyard has been established.

Ask the vendor if yeast was added.

Regardless, add the BM4x4. If you have a wild yeast, the BM4x4 should dominate. If it's actually a preferred wine yeast, let them fight it out for pecking order. You win, either way.

 

[d v]

@winemaker81 @sour_grapes Appreciate both of your feedback! I reached out to the supplier and it looks like you are correct. They replied that they don't inoculate the buckets but do use EC-1118 around their winery and that it was possible that some of the yeast might've ended up in the must by accident while they were inoculating a tank. Not an ideal outcome - the wine must is cab sauvignon and I'd have preferred a red wine yeast to go with it - but at least it will be a reliable ferment.

 

[balatonwine]

added the proper number of campden tablets to kill any wild yeasts that might be present

Simply for reference, and to confirm and verify "proper" (because without this data, any suggestions and input might be invalid):

- What was the pH of the must when you added tablets?

- How many tablets did you add?

 

[Rice_Guy]

* all grapes in the vineyard will have yeast which can be cultured, ,,, therefore the must will have some yeast. (Likewise the grapes will have culturable Acetobacter, mold etc. infections) Yeast are hearty little buggers and a traditional way to inoculate was to take a wooden spoon or pusher that only got used for the fermentation.
* organisms grow in waves where one food substrate is used up and then another organism with a different metabolism takes over. Yeast called “killer yeast” are very efficient at using resources and sometimes release toxic compounds as SO2
* with frozen buckets in the club I hear about 1 in 50 fermentations can’t be knocked out with added meta and in QA samples see about 1 in 5 show obvious gas bubbles.

 

[d v]

Simply for reference, and to confirm and verify "proper" (because without this data, any suggestions and input might be invalid):

- What was the pH of the must when you added tablets?

- How many tablets did you add?

Sure thing. PH was 3.5, and I added 6 crushed campden tablets overall (one per gallon of must).

 

[Steve Wargo]

I use BM4X4 yeast for some of my reds. I like it. It's a powerful yeast mixture. In the past, I had purchased wine in buckets from California, shipped it in a cooler truck. Once brought home they started to ferment the next day cause they warmed somewhat. So maybe the wine was using the native yeast for one or two days prior to pitching the BM4X4 slurry. I never worried about it, cause the BM4X4 is powerful and finished the job. There never was an off-taste to the wine. I think it happens more often than not. Also, purposely started a wine with RC212 yeast and then a couple of days later added BM4X4 just to experiment with complexity. It seemed to work out ok. It's still aging.