Help me w/ 100% Brett starter calculation

[PistolaPete]

Happy Friday!

I have a vial of Brett C. WLP645 and want to do a 1.25 gallon batch with it. Mr. Malty say I need 96 billion cells and the vial has 1.8-2.7 billion cells in it. How big of a starter do I need to get from 1.8-2.7 to 96? I was thinking of starting with a 500ml starter and stepping it up from there. Thanks!

 

[dstar26t]

I just did a 645 starter a month ago. 250mL of 1.048 wort on a stirplate @ 82F for 8 days gave 65 Billion cells. Added 250mL of wort to the original 250mL for a resultant 500mL of 1.048 wort and let that go on a stirplate for 8 more days @ 82F. That grew to 100 Billion.

 

[PistolaPete]

Thanks for quick reply, dstar! Maybe I should start smaller like you did. It sounds like you know your stuff so let me ask you a few other questions...I have so many!

1) Do you mean you had a 500ml size starter at the end? How big of a batch & what OG will you use it in? Will you chill & decant first?

2) How do you know how many cells you got? Are you doing a yeast count or using some sort of calculation to estimate?

3) I have a stir plate also but I was scared I might "beat the culture up" so I was just going to not use it so I can see when the starter is done fermenting and go from there. Should I not be worried about using a stirplate for so long?

 

[Coff]

These pitching rates are all an approximation, none of us are 100% sure how many cells we have after all of these stepped starters but it gets you in the ballpark.

I like to use http://yeastcalculator.com/ for starters and pitching rates, there are more tools for stepping up and entering the cell count of your package.

You didn't mention the OG of your batch, for a 1.25 gallon batch need 96 billion cells you must be brewing something huge, or youre trying to pitch lager rates as some people do with 100% Brett, I pitch ale rates with great success. Yeastcalc says you'll need 43b cells for a 1.25 gallon batch at SG 1.050 and you can get there with a 300ml starter assuming you started with 2b cells from the vial.

I dont see any reason to do 3-4 steps, if youre brewing a big beer and need 96b cells like you say then you can do a 750ml starter and hit over 100b cells. I usually stir my Brett starters for 2 days then turn the stirplate off and let it finish for 7-10 days, Chad Y says that a Brett starter will go through a 2nd growth phase after 5-7 days.

 

[PistolaPete]

Coff, Thanks for the info and nice blog you have there! I dont have an exact OG yet but I plugged 1.055 into Mr. Malty for an estimation and went with lager rates since that is what some people say to go by with 100% Brett. I had also thought about only using the stirplate for the first couple of days, so your response gives me the confidence to try that. I don't mind pitching lager rates but if I can just do a one step starter and be done with it, that would be great! But I noticed on yeastclaculator.com it says I would need to first do a .075 (75ml) starter to keep the incolculation rate at around at least 25 million/ml for best yeast health? Am I missing something? And what do you mean when you say that Brett goes through a second growth phase after 5-7 days?

 

[dstar26t]

Thanks for quick reply, dstar! Maybe I should start smaller like you did. It sounds like you know your stuff so let me ask you a few other questions...I have so many!

1) Do you mean you had a 500ml size starter at the end? How big of a batch & what OG will you use it in? Will you chill & decant first?

2) How do you know how many cells you got? Are you doing a yeast count or using some sort of calculation to estimate?

3) I have a stir plate also but I was scared I might "beat the culture up" so I was just going to not use it so I can see when the starter is done fermenting and go from there. Should I not be worried about using a stirplate for so long?

1) Yes, I had 500ml at the end. This is to ferment a Berliner so it was soured to pH 3.0 first with grain and 5335 and after adding the entire 645 starter, the final OG was 1.038, 3.5 gallons.

2) I did cell counts. Brett does not follow the same growth curve as sacc.

3) To get good growth with Brett, it's best to use a stirplate, it requires a lot of oxygen.

Nate