Yeast pitching question

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lucus_j

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Hi All,

I'm using Brewfather to put together a 25L (because I no-chill in a 25L cube) Proper Job inspired English IPA sort of recipe. The OG is 1.059, FG 1.014.

I'm stuck on how much yeast to pitch; the pitch calculator calls for 272 billion cells - and is happy with 21g @ 13billion cells/g of dried yeast, i.e. 2x 11g packets of dry yeast @ 10billion/g.

The problem is that most dry yeast packs are 10g @ ~6billion cells/g. Adjusting the calculator suggests 5 packets of yeast!!!

I've got 3x MJ M36, 1 x nottingham and 2 x 6g packets from a wilko kit, oh and 500g light spraymalt.

So what's the solution? 2 packets? 3? A starter? I haven't done a starter before but assume that you pitch only thr cultivated yeast and ditch the wort?

I was leaning towards 1x MJ M36 + 1x nottingham.

All answers gratefully received!

L
 
um with 25 litres of 6% you'd not need more than 2x10g packets of dried yeast.

maybe theres a bug in the calculator

I've brewed 20 litres 12%+ beer with a single pack of MJ french saison yeast (re-hydrated) so 5 packs is overkill.

p.s. in my sig all below were at least 20 litres using a SINGLE packet.
 
um with 25 litres of 6% you'd not need more than 2x10g packets of dried yeast.

maybe theres a bug in the calculator

I've brewed 20 litres 12%+ beer with a single pack of MJ french saison yeast (re-hydrated) so 5 packs is overkill.

p.s. in my sig all below were at least 20 litres using a SINGLE packet.

Thanks for your input!

I had read somewhere that pitching rate calculators grossly overestimate what's actually needed and in fairness I've only ever used 1 pack of yeast - US-05 typically - for 23L & 25L batches.

Cheers!
 
I am really dubious about yeast pitch calculators going by the one on brewers friend 11g of yeast for a 23L batch of session bitter (1.036) would be under pitching. I’m not saying that under pitching isn’t a thing but I take the general rule that an 11g packet of yeast is fine for a typical batch of beer.
 
Last batch of stout I made, I realised at pitching time that I only had half a packet of US-05 in the fridge. I thought I had more full packets in the cupboard, but I didn't. I ummed and ah-ed as to whether to use some other yeast, but in the end decided to pitch just the half-packet.

Reader, it was fine. I would be very suspicious of claims that more than one packet of yeast would be required for a batch. Maybe with some mega-strength beers? But I don't brew anything like that anyway.
 
I would be very suspicious of claims that more than one packet of yeast would be required for a batch.
I know one pack of Belgian yeast can handle an 8% ABV well enough. I got into pitching two packs since most of my beers are above 10%. I'm not willing to take the time and test one pack for them though. It might be like throwing salt over your shoulder for luck but it's only an extra few dollars.
 
I found on another forum or thread somewhere, the results of testing from someone who worked in a laboratory, and he said that all their measurements and tests actually showed that all packets of yeast contain appr. 200 billion cells. I used that number in my own calculator, and I haven't had any problems pitching the correct amount of yeast. With correct I mean that my fermentation starts in less than 24 hours, mostly even in less then 12 hours.
  • OG (in Plato) * volume of wort (in litre) * Pitch rate = amount of cells (in 10^9, billions)
  • amount of cells * 20 = amount in grams of dried yeast to use
Double this when fermenting lagers, or stouts and porters with much roasted malts.
 
Further to my post #7, a slightly strange thing: this brew which was pitched with only half a packet is still plinking away from its fermentation locks long after I normally bottle, with a gravity around the 1012 mark which leaves me thinking it could drop a little further yet. If I bottle it tomorrow (and it looks like I could leave it longer than that), it will have been in secondary fermentation 9 days. That might not seem that long, but it is the longest I have had in over 30 brews this year. i'm just wondering whether the smaller amount of yeast has anything to do with it, because it's not happened like this before.

I reckon there's no harm in leaving it till the middle of next week to bottle, come to that.
 
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