Hello I just happen to pick up The 4TH Edition of How To Brew by John Palmer. My questions is about the article where he talk about Yeast starter an stir-plate. He say One important consideration is that the stir-plate should only be used for the first half of the propagation, for example , 12-18 hours when assuming 24- 36 hours of total propagation Time. Now what is John Palmer saying exactly ?
I am confused as well by this. What i do build a starter. For 36 hours. On the stirplate. Than put it in a mason jar. in to the fridge untill brewing day. Separate the water from the the dme and yeast. Once on room temp i pitch the yeast
Maybe he’s eluding to, you are preparing the yeast for pitching… Rather, allow the yeast build up the amino acids needed for budding… You’re not wanting them to start that process until they are in the wort. Then the budding process begins, and there will be enough FAN in the new wort to help the next coming generations keep rolling along… Sneezles61
I know nothing about this so this is just a thought. Could it be relieving some of the yeast from the shear stress of being banged around by the stir bar. Is this part of the reason for the shaken not stirred method of propagating yeast.
I just tried out this method of using the stir plate for only a short time.
I used a stir plate for years, but stopped a couple years ago and started using the SNS method. I get results as good as with a stir plate with less hassle. Old Dog...New Tricks | Experimental Homebrewing
Shear stress is technically one of the reasons an SNS starter is superior to a stir plate. After all, that’s why yeast manufacturers use shaker tables and not stir plates when they propagate yeast. But for me the reason is that SNS is far easier and faster than a stir plate and produces results that are at least equal.
I’ve been preaching the SNS method when I read about it and tried it years ago. BTW anybody want to buy a maelstrom stir plate!?!?
Actually if I’m propogating small amounts of dregs from bottles or old yeast I’ll stir plate until I get a large enough population then will go SNS.
Could be that John Palmer feels that in the beginning the cell density is low and not too many yeast cells, if any, would be damaged by shear stress. But after 12 hours the cell density is high enough that shear stress becomes a problem. Right or wrong, that logic is why I now put my starter on a stir plate the night before brew day and when I get up the next day I take it off and begin the shake and stir method. I figure that a stir plate overnight is better than nothing, which is what would be happening when I’m sleeping. Or it could be that I’m just rationalizing because I built my stir plate a couple of months before @denny said stir plates are bad!
Not really bad, but unnecessary. But it’s homebrewing so you get to make your own decision!
Really gentlebrewers… Do you put your carboys/fermenter on a stir plate? I don’t, and all seems to end very well… Maybe I’m a wierdo… then, I don’t care!! Sneezles61
My maelstrom can reportedly go up to 5gal carboys. Think about that yeast starter!
Oh, they do…they do. I gave it…a whirl.
Shaking not stirred… I refer to that as… shake the living bejesus into it!! I no longer use a stir plate… Sneezles61