Yeast harvesting process

[pretzelb]

I was reading the yeast harvesting article at brulosophy and I'm a bit confused on a few points.

First I assume this starts from the point of making a normal starter meaning you buy the yeast and DME and target a recipe. But it also sounds like this could be based on a previous batch of a harvest. Then you calculate how to produce extra cells, which I assume is supposed to be for the batch you are about to brew. But the instructions say to overbuild it by 100 billion cells, which appears to be a constant regardless of the beer you are brewing. Then after time on the stir plate and chill session, it is swirled and put into a mason jar but this seems like a random amount instead of trying to target a proper starter size. Since many people have starter calculators it seems odd to just guess at this point. But the main confusion for me is the remainder of the starter is then put into cold storage. What really puzzles me is what is done with that next? Is that the basis to start the process again for your next batch? If so then shouldn't this be stored in a mason jar at normal fridge temps for future use?

 

[JLeuck64]

I was reading the yeast harvesting article at brulosophy and I'm a bit confused on a few points.

First I assume this starts from the point of making a normal starter meaning you buy the yeast and DME and target a recipe. But it also sounds like this could be based on a previous batch of a harvest. Then you calculate how to produce extra cells, which I assume is supposed to be for the batch you are about to brew. But the instructions say to overbuild it by 100 billion cells, which appears to be a constant regardless of the beer you are brewing. Then after time on the stir plate and chill session, it is swirled and put into a mason jar but this seems like a random amount instead of trying to target a proper starter size. Since many people have starter calculators it seems odd to just guess at this point. But the main confusion for me is the remainder of the starter is then put into cold storage. What really puzzles me is what is done with that next? Is that the basis to start the process again for your next batch? If so then shouldn't this be stored in a mason jar at normal fridge temps for future use?

Yeah that 100 billion count... just can't bring myself to do it! Way too scientific for my home brewing.

I've been over building my starters like this: conventional wisdom says a starter should be 100g of DME per liter of water so what I do is put 150g of DME into a 1.5L starter and place it on the stir plate for 36 - 48 hrs before brew day. On brew day, before I pitch in the yeast, I sterilize a pint mason jar. Then I swirl up the starter real good and pour some into the mason jar. That will become the next starter, and I place it into the fridge until the next brew day. The rest of the starter goes into the beer on brew day. I've had pretty good success with this method and it really saves $$$ because you are using the same yeast for many generations ( ;

 

[DurtyChemist]

Yes the second batch is the same as the first. He says to store 100 billion because that is what is in a retail yeast pack.

Look up homebrew dad yeast calculator in your favorite search engine and download it. It helps you know how much you'll need to make for a starter and what amount to store. He has up to 4 steps so you can make a LOT of yeast.

 

[pretzelb]

Yeah that 100 billion count... just can't bring myself to do it! Way too scientific for my home brewing.

I've been over building my starters like this: conventional wisdom says a starter should be 100g of DME per liter of water so what I do is put 150g of DME into a 1.5L starter and place it on the stir plate for 36 - 48 hrs before brew day. On brew day, before I pitch in the yeast, I sterilize a pint mason jar. Then I swirl up the starter real good and pour some into the mason jar. That will become the next starter, and I place it into the fridge until the next brew day. The rest of the starter goes into the beer on brew day. I've had pretty good success with this method and it really saves $$$ because you are using the same yeast for many generations ( ;

Oh, so the part you put into a mason jar becomes the base for your next starter? Do you drain the wort from the top and use the same 150g and 1.5L basis again?

 

[JLeuck64]

Yes, swirl it up real good then pour it into a pint sized mason jar. That will become the starter for the next batch, 150g light dry malt extract per 1.5L of water.