rehydrated yeast dilemma multiple choice

[Braumeister]

I rehydrated some lager yeast but then realised it will take a long time to get the wort down to pitching temp 10-14C. So I’m going to have to leave the wort overnight to get to that temp. What shall I do?

a)pitch anyway now at 20C

b) keep the yeast in the fridge overnight and pitch in the morning

c) dump the yeast and buy some more in the morning and pitch that

d) chuck some of the wort in the yeast and make it into a yeast starter overnight?

e) something else

 

[Sadfield]

A. Have a read of this from Dr. Chris White from White Labs, it's fine for the lag phase of Lager to start at c20C.

https://byo.com/article/fermentation-time-line/

 

[Braumeister]

A. Have a read of this from Dr. Chris White from White Labs, it's fine for the lag phase of Lager to start at c20C.

https://byo.com/article/fermentation-time-line/

I like that one it’s the easiest option

 

[Pennine]

A, these are the rehydrating instructions from 3470

REHYDRATION INSTRUCTIONS: Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 21 to 25 °C (70°F to 77°F). Leave to rest 15 to 30 minutes. Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel. Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the wort using aeration or by wort addition.

 

[Agentgonzo]

Progressively sprinkle the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the wort using aeration or by wort addition.

I've always wondered why you sprinkle it on the surface, then let it sit there for a while before mixing. Why not just mix it in straight away?

 

[peebee]

I've always wondered why you sprinkle it on the surface, then let it sit there for a while before mixing. Why not just mix it in straight away?

I think it's for the same reasons as "rehydrating". Keeping the yeast clumped up and only slowly "wetting" keeps the shock to the yeast down. Subjecting the yeast to sudden changes of liquid density murders quite a few cells (osmotic shock). It's a tough life being a single cell entity!

And answering the OP: Waking up a load of starving cells in a media (rehydration water) devoid of any food (sugar) won't keep them happy for long. At which point the situation murders many of them too.

Following the rehydration instructions to the letter is no bad recommendation: I've only just started to follow the temperature advice; rehydrating in 30-35°C water. I've always been too scared to use such warm water ... Flippin' heck, the yeast doesn't half start quick doing it "properly"!

 

[Braumeister]

Thanks, I pitched last night at around 20c. Has dropped to 13c now. There is a airlock activity only every 30 seconds so early days, hopefully picks up quicker soon.

First attempt at a lager, hopefully it’s not really slow. My last brew was an ale with M36 liberty bell and it went from 1.051 to 1.013 in 48 hours and was done in a week. I think lagers are supposed to take longer than ales to ferment because of the low temp?

I watched David Heaths Vienna lager video and he suggested speeding it up by raising a degree each day after reaching half way to final gravity so I might try that.