Yeast Rehydration and Restarting stuck Ferments
Posted: Fri Oct 28, 2016 7:25 amThis subject comes up from time to time.
I thought I would share the latest thinking from my course. The process of rehydration & restarting a stuck ferment are in the attached PDF.
The key points for me, seemed to be that
- Yeast don't like being started - they prefer simple rehydration in water (to recover them from their dried state). Once rehydrated they can then acclimatise to their environment. if you start them, they go through the acclimatisation process (lag) twice and this can cause yeast shock (failure)
- Yeast prefer to be rehydrated in water - not high concentrate sugary/wash/wort/mash.
- Rehydrating will lead to a much greater cell count per ml than sprinkling, important for speciality yeasts. That said if using Baker's yeast it's sooo cheap, dosing at 100 g per 25 L mitigates that.
-For obvious reasons dechlorinated water (boiled) is best.
This is for dried powdered yeasts only.
I thought I would share the latest thinking from my course. The process of rehydration & restarting a stuck ferment are in the attached PDF.
Best Practise Yeast rehydration- .pdf- (76.51 KiB) Downloaded 89 times
The key points for me, seemed to be that
- Yeast don't like being started - they prefer simple rehydration in water (to recover them from their dried state). Once rehydrated they can then acclimatise to their environment. if you start them, they go through the acclimatisation process (lag) twice and this can cause yeast shock (failure)
- Yeast prefer to be rehydrated in water - not high concentrate sugary/wash/wort/mash.
- Rehydrating will lead to a much greater cell count per ml than sprinkling, important for speciality yeasts. That said if using Baker's yeast it's sooo cheap, dosing at 100 g per 25 L mitigates that.
-For obvious reasons dechlorinated water (boiled) is best.
This is for dried powdered yeasts only.