Yeast Estimates from dregs

[lucianthorr]

I've dug around a little and haven't found what I'm looking for so I figured I should just ask here.

Is there a chart or any kind of reference for how to estimate what your cell count is if you're building a starter from dregs?

I just finished my keg of 100% brett IPA and I would LOVE to reuse the bottom of the keg to get a second batch started. I know with brett blends, it might not be the exact same ratio on the second go-around but I think it's worth a shot.

Second question since it just popped in my head,
Are keg dregs as viable as bottle kegs? I can see there being a difference since kegs (traditionally) aren't force carbed instead of conditioned.

 

[logos]

I would imagine that dregs from a home brew keg would be much more viable than commercial bottle dregs given no exposure to heat and being much fresher.

I don’t think you will find any chart that can predict the number of viable cells in dregs. There are just too many factors involved including that they dregs contain precipitant material other than yeast.

I don’t know about reusing a blend - seems unlikely that the ratio of strains in it will be maintained - does not mean that the beer will be bad though.

Another option - plate out the yeast on agar plates (to make MEA - malt extract agar - you would pretty much just need plates, DME and agar which you can get cheap on amazon or in an Asian food store) which would let you separate the strains and then grow them is pure culture. Then just take one colony and build it up into a pure starter.

 

[lucianthorr]

Great suggestions, thanks!
I actually think I have all the equipment for plating yeast b/c I bought Bootleg Biology's yeast harvesting kit last year and still haven't gotten around to putting it to use. I might have to give it a shot. Do you have any reference links that I could use for that sort of isolating strains? Biology was never my forte in school so it's all going to be new to me. (If not, I'm sure I can find something on youtube)

My only hypothesis for getting a yeast count estimate from dregs was if there was a maximum population for a given starter size and gravity...I could step the dregs up within a starter until they met some threshold that I could be confident could ferment out 5 gallons.
That said, I don't really know what I'm talking about.

Thanks again for the response. Definitely sounds like a worthwhile path to pursue.

 

[logos]

It is pretty easy on the whole. Basically just put a small amount of dregs on a plate. It is a bit of a guessing game how much but basically you want it to be little enough that you get individual colonies that represent individual cells. With bottle dregs I have been putting about 200uL (so 20% of a mL). Worst case if you grow too much east to see the separate colonies then you pick just a little with a sterile (read burnt in a flame for a couple seconds) wire loop and then streak that onto a new plate.