Who's Numbers Do You Like?

Hello Everyone,

I’ll be brewing a Kolsch this coming weekend and have a yeast starter question. The OG for the beer will be around 1.050, but the yeast I’m using (Wyeast 2565) is about 6 months old. I’m planning on making a 2 liter starter on a stir plate, but am wondering if I should step it up once more before brew day. If I use Kai’s formula on yeastcalc.com, I see that I should be able to generate enough cells to properly ferment with just the 2 liter starter, but if I use Jamil’s formula, I’m told that I’ll need to step up afterward. Who’s numbers would you go with?

Yeastcalc is probably sufficient enough. I used it to build up a starter for a helles recently. Worked out just fine.

FWIW I’ve read articles (that I agree with) that Mr.Malty (Jamil’s calculator) is very conservative when it comes to viability. I’ve read 2 articles that suggest if stored properly yeast viability is much higher than what his calculator suggests.

I’m pretty sure you’ll be just fine at 2 quarts (for 5 gallons), but personally I’d go a little higher to 3 quarts for a Kolsch. So just a small step upwards – you don’t need 3.5-4 quarts like you would for a lager.

I like stepping more than huge starters. Stepping from 1qt to 2qt starter gives you more yeast than a 4qt starter does. It’s only slightly more work and isn’t such a pain to chill down after boiling and doesn’t fill the growler all the way to the top, risking blow off. You just have to plan ahead a little more. But if you harvest the yeast, you don’t have to worry about it for the next batch. But this is what I do for lagers…ales are a lot easier to plan for, as far as yeast goes, unless you’re using pretty old yeast.

Thanks, guys. After this one finishes fermenting, I think I may cold crash it and then see how much yeast I’m left with on the bottom of the flask. If things look a little sparse, I’ll go ahead with another 1.5 or 2 liter starter. Thanks again!

I believe that Kolsch yeast strains are low flocculating so I would suggest you cold crash for at least 48 hours to make sure you aren’t decanting off a bunch of your higher flocculating cells. I did a 2 step starter of WLP300 (heffewiezen) last week and I noticed that after more than 24 hours of sitting in the fridge there was about 1" at the top which had no yeast in it then a 5" or so light haze which was clearly a lot of yeast left in suspension. After about 48 hours that haze went away. Due to this it took a full week to do a 2 step starter. I may have been overly cautious but I’d always rather err on the side of overpitching.

I believe that Kolsch yeast strains are low flocculating so I would suggest you cold crash for at least 48 hours to make sure you aren’t decanting off a bunch of your higher flocculating cells. I did a 2 step starter of WLP300 (heffewiezen) last week and I noticed that after more than 24 hours of sitting in the fridge there was about 1" at the top which had no yeast in it then a 5" or so light haze which was clearly a lot of yeast left in suspension. After about 48 hours that haze went away. Due to this it took a full week to do a 2 step starter. I may have been overly cautious but I’d always rather err on the side of overpitching.[/quote]
Sage advice, mattnaik – thanks!

Kai’s are based on his own research. Jamil’s are based on a scale-up of Chris White’s no-stir starter values.

I have been wrestling with this as well. I am a long time Mr. Malty user but recently went over to YeastCalc. I have been splitting the difference for the last several brews and have done well. I probably have been over pitching for years without any ill effect. I just wonder what my usual 3787 will do when under a little more stress. I’m set to do a 90min IPA clone Tues with a 3mo old vial and a 3L starter and I’ll continue to follow this thread.