Cultivating culture from grape skins

[hotwatermusic]

I took some bunches from my mom's backyard, rinsed them, half crushed, and dropped them into some canned wort. They are just starting to bubble- no observable pellicle yet- and I've noticed what appears to me to be little colonies of mold growing on the inside of the flask.
Since I am only using this in the hopes of growing a larger amount of brett etc. Can i get away with ignoring this?
I will at least be transferring to another flask once it has been through a full fermentation.
I still don't know if it would go into beer at all. I was thinking I would add it to my sourdough starter (which isn't overly old or precious).

 

[RPh_Guy]

I wouldn't recommend keeping a moldy culture.

 

[hotwatermusic]

I wouldn't recommend keeping a moldy culture.

Easy enough to do again. Do you think acidifying the wort might help?

 

[RPh_Guy]

The process I recommend is to:

• Pre-acidify to 4.0-4.5 with lactic acid.
• Add some quality yeast nutrient.
• Aerate well initially, but then keep the culture anaerobic (e.g. under airlock or in a mason jar 1/8th turn from closed). Reducing the headspace is a good idea as well.

This method has a high rate of success. It's very tempting to open it to get a nose full of the wonderful aroma, but that often leads to mold growth in my experience. Keep it closed until it's done and then pitch part of it into a new starter if the gravity and aroma are satisfactory based on whatever your goal is.

Be aware that Brett is relatively uncommon, and most wild cultures will poorly attenuate wort, around 50-55% apparent attenuation.

 

[hotwatermusic]

The process I recommend is to:

• Pre-acidify to 4.0-4.5 with lactic acid.
• Add some quality yeast nutrient.
• Aerate well initially, but then keep the culture anaerobic (e.g. under airlock or in a mason jar 1/8th turn from closed). Reducing the headspace is a good idea as well.

This method has a high rate of success. It's very tempting to open it to get a nose full of the wonderful aroma, but that often leads to mold growth in my experience. Keep it closed until it's done and then pitch part of it into a new starter if the gravity and aroma are satisfactory based on whatever your goal is.

Be aware that Brett is relatively uncommon, and most wild cultures will poorly attenuate wort, around 50-55% apparent attenuation.

Thanks. Great suggestions.