I am making a starter of London ESB for a Porter of 1.055. I only had a two liter Erlenmeyer for the stir plate. I had a smack pack produced in May. Mr. Malty suggested a two liter starter. I also had a smack pack of ESB made in Jan. Mr. Malty wanted to use 4 or 5 liters for one pack. I used both smack packs in a 1.7 liter starter. There is a lot of yeast being produced. So, will the yeast be viable as in growth phase and will it be to much to pitch in a 5 gallon batch?
Over pitching really requires a lot of yeast and a 1.7 let starter isn’t really that big. So without doing any calculations I’d say your fine.
MrMalty is more of a guesser than a calculator. It’s a good guesser that I use all the time with good results, but it’s really just a guess. Without actually counting your yeast and testing viability, you have no idea how much yeast you’re actually pitching.
The good news is it’s basically impossible to overpitch, on a homebrew scale, unless you really try to overpitch. I’m talking like 5 smack packs, and even then it’d probably still make good beer.
I’m wondering if a 1.7 L starter will be big enough for 2 smack packs. IIRC, there’s needs to be enough “food” for they yeast to rebuild it’s glycogen reserves at the end of fermentation. In 1.7L there may not be enough. I don’t know for certain, just thinking “out loud”.
They’re pretty old packs though. Something like 70 billion cells total between them. So unless you’re using a stir plate and/or aeration, you may be under-pitching.
Denny, I was wondering the same thing about reserves. I did add nutrient to the starter but it is highly floculating in two days. I don’t know if that means it ran out of steam early. I suppose it is pitch and learn.
1 pack in 1 L on a stirplate will double the yeast.