Mr Malty calculator with washed yeast?

[firefly765]

I've been washing yeast using this method for a couple years now: https://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/

I generally use the washed yeast from 1 jar in a 1.7L (ish) 1.035 (ish) starter on stirplate for 24 (ish) hours, cold crashed & decanted, in my beers (5gal, or 2 starters in 10 gal) of 1.040-1.060 OG's. I've been blindly using this technique with really great results....

Recently I've been wondering how to step up a single jar to a 10 gal beer.....The Mr. Malty conversion tool has confused me in the past so i just have been doing "what works".

Under the tab "repitching from slurry" It states I need 189 ml (thats over 3/4 cup) of yeast with no mention of a starter.......according to my calcs one jar of yeast is 30-40 ml's of slurry.......???????

How could i need that much yeast for a "normal gravity beer"???

Thanks for any advice!

 

[LLBeanJ]

What mrmalty considers slurry is unwashed yeast straight from the fermenter. I would only use that option if direct pitching slurry.

When using clean yeast to step up a starter, you would be better served to use www.yeastcalculator.com. With washed yeast, you can figure 2-3 billion cells per ml.

 

[firefly765]

What mrmalty considers slurry is unwashed yeast straight from the fermenter. I would only use that option if direct pitching slurry.

When using clean yeast to step up a starter, you would be better served to use www.yeastcalculator.com. With washed yeast, you can figure 2-3 billion cells per ml.

Ok, that looks better.
So, if i consider my washed yeast is 30 ml's that = Approx 60 billion cells @ 59% viability (2 mo old) in a 1.7L starter (Zaniseeff) =165 Billion
2nd step would give me 381 Billion with same starter ##'s ....still not enough for a 10.6 gal 1.054 beer (401 billion)

What would be the process for the step? Make a starter....crash......decant....make another starter with that yeast??

What is a Zainisheff stirplate vs Troester?

 

[LLBeanJ]

Yes, you have the right idea. If you're within ± 10-15% of the cell count, that would be close enough. Change it to use Kai's strirplate option and you should have more than you need anyway.

I do the first step, cold crash for a few days, decant, add more wort and do it all again.

Use the Troester stirplate option. Jamil's growth rates are too conservative and you'll end up overpitching. Kai's growth rates are more aligned with reality.

 

[firefly765]

Yes, you have the right idea. If you're within ± 10-15% of the cell count, that would be close enough. Change it to use Kai's strirplate option and you should have more than you need anyway.

I do the first step, cold crash for a few days, decant, add more wort and do it all again.

Use the Troester stirplate option. Jamil's growth rates are too conservative and you'll end up overpitching. Kai's growth rates are more aligned with reality.

OK, Thanks man! I guess i was just using blind ignorance before!
how long is a good cold crash between starters?
And, how long on the stirplate.....24 hrs?

 

[firefly765]

So.....if my washed yeast looks like this ~1.5oz=44ml=105 (2.4 / ml) billion cells would be my start point?
If it's 2 mo old that gives me 59% viability and 61.95 billion cells and so on from there????

 

[LLBeanJ]

So.....if my washed yeast looks like this ~1.5oz=44ml=105 (2.4 / ml) billion cells would be my start point?
If it's 2 mo old that gives me 59% viability and 61.95 billion cells and so on from there????

Yeah, that's pretty much how I do it. I actually start with clean yeast harvested from a previous starter, but the process is the same... Start with an estimated cell count and viability date and use the yeastcalculator site to plan the steps based on what you need to pitch (I also plan for a little more so that I can save some for a future starter - not that much, around 20-50B cells).

I like to cold crash for 5-7 days between steps to really allow extra time for the slower flocc'ing yeast in suspension to drop so they don't all get poured out when the starter beer is decanted, but I've seen others go with 24-48 hours and report good results. I typically begin my 2 and 3-step starters about 2 weeks prior to the planned brew day. If the first step is small enough, I won't bother to crash and decant before the 2nd step, I just add more wort to what's already there.

As far as time on the stir plate... 24 to 48 hours. Depending on how old the yeast is (I've used yeast that had been sitting in the fridge as long as 9 months before), it may take a couple days to finish. Once you get past that first step or if going in with fairly fresh yeast, 24 hours should do it.

 

[firefly765]

Yeah, that's pretty much how I do it. I actually start with clean yeast harvested from a previous starter, but the process is the same... Start with an estimated cell count and viability date and use the yeastcalculator site to plan the steps based on what you need to pitch (I also plan for a little more so that I can save some for a future starter - not that much, around 20-50B cells).

I like to cold crash for 5-7 days between steps to really allow extra time for the slower flocc'ing yeast in suspension to drop so they don't all get poured out when the starter beer is decanted, but I've seen others go with 24-48 hours and report good results. I typically begin my 2 and 3-step starters about 2 weeks prior to the planned brew day. If the first step is small enough, I won't bother to crash and decant before the 2nd step, I just add more wort to what's already there.

As far as time on the stir plate... 24 to 48 hours. Depending on how old the yeast is (I've used yeast that had been sitting in the fridge as long as 9 months before), it may take a couple days to finish. Once you get past that first step or if going in with fairly fresh yeast, 24 hours should do it.

Great info! Thanks man.
I was in the ballpark before....but seeing how that yeast calculator works really helps. It will save me on yeast and DME by just changing my ##'s around and doing a "step up" instead of 2 separate starters.....Always learning!

 

[Brew_G]

So.....if my washed yeast looks like this ~1.5oz=44ml=105 (2.4 / ml) billion cells would be my start point?

If it's 2 mo old that gives me 59% viability and 61.95 billion cells and so on from there????

Pop in a 1.5L 1.035 starter. It should leave you with plenty of yeast for pitching into a 5-gallon medium-ABV beer. If you're doing a 10-gallon batch, you may need to step that up even more if you have a container large enough for it.

That said, that's a pretty thick yeast cake, so you might be able to figure on more than 2.4 billion cells per mL.

 

[jjbanks]

Yeah, that's pretty much how I do it. I actually start with clean yeast harvested from a previous starter, but the process is the same... Start with an estimated cell count and viability date and use the yeastcalculator site to plan the steps based on what you need to pitch (I also plan for a little more so that I can save some for a future starter - not that much, around 20-50B cells).

I like to cold crash for 5-7 days between steps to really allow extra time for the slower flocc'ing yeast in suspension to drop so they don't all get poured out when the starter beer is decanted, but I've seen others go with 24-48 hours and report good results. I typically begin my 2 and 3-step starters about 2 weeks prior to the planned brew day. If the first step is small enough, I won't bother to crash and decant before the 2nd step, I just add more wort to what's already there.

As far as time on the stir plate... 24 to 48 hours. Depending on how old the yeast is (I've used yeast that had been sitting in the fridge as long as 9 months before), it may take a couple days to finish. Once you get past that first step or if going in with fairly fresh yeast, 24 hours should do it.

So, i have similar mason jars filled with about that same amount...You'll notice the actual yeast layer (the white stuff on top of the beige stuff) is much less than 1.5 oz. Do you measure the whole trub + yeast layers when you calculate the yeast count on washed yeast. This point in question has been bugging me for some time and can't seem to find an answer. Thanks.

 

[LLBeanJ]

So, i have similar mason jars filled with about that same amount...You'll notice the actual yeast layer (the white stuff on top of the beige stuff) is much less than 1.5 oz. Do you measure the whole trub + yeast layers when you calculate the yeast count on washed yeast. This point in question has been bugging me for some time and can't seem to find an answer. Thanks.

Without the necessary tools to actually count cells, all you can really do is guestimate it as best you can. If it were all pure (or mostly pure) yeast, I'd estimate 3B cells per ml. The presence of trub is going to reduce that figure somewhat. I'd calculate based on the total amount of solids (both layers) and go with a figure of around 2B cells per ml and just go with it. So, if you have approx. 150 ml of slurry that is considered to contain 2B cells per ml, then you'd be looking at somewhere in the neighborhood of ~300B cells. Take that, along with the viability date and enter it into yeastcalc to determine how many viable cells you have and that will tell you if you need to make a starter or not.

Is this accurate? Probably not as much as it could be, but that's not really important. What is important is consistency and if you use the same method each time, you'll have that. Then, let the finished beer tell you if you need to adjust your variables. Before you can do that, however, you need to have a starting place, which is what I'm giving you. I promise you will get good beer doing it this way (assuming you don't have problems elsewhere in your process).

 

[firefly765]

I was just revisiting my old thread playing around with the yeast calculator...and according to it, my initial yeast count hardly matters at all, right?
For instance, if i start with 50B cells @ 20% viability make a 1.5 L starter=221B viable cells
If i start with .5B cells @ 20% viability make a 1.5 L starter=211B viable cells!

So, unless I'm totally overlooking something my washed yeast can be in much smaller containers (quantities) to begin with.......right?
i.e. a 8oz or 4oz mason jar to begin with and harvest much more yeast! (more jars).

 

[LLBeanJ]

The older the yeast, the lower the viability and as viability decreases, cell count becomes less of a factor. This is why when I save yeast from a starter, I only shoot for 30-50B cells. By the time I use it again, viability is likely to be 20% or less, so it matters little whether I'm starting with 30B cells @ 20% viability or 100B cells @ 20% viability.

 

[firefly765]

The older the yeast, the lower the viability and as viability decreases, cell count becomes less of a factor. This is why when I save yeast from a starter, I only shoot for 30-50B cells. By the time I use it again, viability is likely to be 20% or less, so it matters little whether I'm starting with 30B cells @ 20% viability or 100B cells @ 20% viability.

But the differance between 50B & .5B yeast cells to start is only 10B (221B vs 211B) after a 1.5L stirplate, so my starting count can be very small as long as i make a good starter, right?

 

[LLBeanJ]

Yes, that is right. 1.5L of wort is going to produce a set amount of cells, regardless of the starting cell count.

But..... when starting with that small of a colony, it's best to step up at least a couple of times, rather than going all out with a 1.5L starter right off the bat. It's probably a good idea to dilute your starter wort to 1.020 for that first step too. If I was starting with .5B cells, I'd prolly do something like:

Step 1: .25L (1.020 wort)
Step 2: .5L (1.040 wort)
Step 3: 1L (1.040 wort)

 

[estricklin]

I have found that for 10 gallon batches, you pretty much HAVE to start using 1 gallon starters, otherwise your going to be doing 2 or 3 steps and that's time consuming, and more chances for contamination. I find that I can take 50 ml of slurry and generally step it up once in a gallon starter and get the number of cells I need. I usually check a few different yeast calculators, I don't bother with the Mr. Malty one anymore because as others have said, it's VERY conservative.

 

[firefly765]

Yes, that is right. 1.5L of wort is going to produce a set amount of cells, regardless of the starting cell count.

But..... when starting with that small of a colony, it's best to step up at least a couple of times, rather than going all out with a 1.5L starter right off the bat. It's probably a good idea to dilute your starter wort to 1.020 for that first step too. If I was starting with .5B cells, I'd prolly do something like:

Step 1: .25L (1.020 wort)
Step 2: .5L (1.040 wort)
Step 3: 1L (1.040 wort)

Gotcha. I wasn't going to start with.5B cells.....just an observation......probably more like 20B at the least....that would fine to do a 1.5L + 1.5L......right?

 

[LLBeanJ]

If you're using Yeastcalc, ideally you want to keep the inoculation rate between 25 & 100 for a healthy propagation.