Rehydrating yeast

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An Ankoù

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Sorry if I didn't make myself clear, I have read and I believe understood the posts so far on this thread, I meant wort from the kettle, if I recall it's 100ml, cooled to 35c, then yeast pitched in. left to settle for 20 mins, stirred once and then pitched to the cooled wort in the FV.

What's the difference with using boiled/cooled tap water and wort to rehydrate please?
If I understand this correctly, part of the process of dried yeast becoming active is that the cell walls have to be reconstituted. It would seem warm water is more suitable than wort as there is less osmotic pressure on the newly hydrating cell while this is happening.
What I don't get is if pitching directly onto the chilled wort results in some yeast mortality, why do other cells survive and become viable.

It's quite possible I've got the wrong end of the stick, though.
 

Cwrw666

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Manufacturers provide sufficient yeast in a pkt to start a batch of around 5 gallons by sprinkling because not everybody can be bothered or has the sanitary technique to rehydrate.
Think you hit the nail on the head there.
In other words rehydration is a waste of time as the quantity of dry yeast supplied assumes the cell loss rate associated with sprinkling.
 

An Ankoù

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Think you hit the nail on the head there.
In other words rehydration is a waste of time as the quantity of dry yeast supplied assumes the cell loss rate associated with sprinkling.
Exactly. And since we can reuse the yeast by top-cropping or pitching on the cake, after the initial pitch, the issue becomes academic. Except with recipes (usually for lagers) which say pitch two packets of yeast. If I were anti-rehydration, I think I'd pitch into a half batch first to build up enough yeast for a full batch. I do this anyway, when I'm recovering yeast from a bottle since it's a way of building a starter that gives some immediate reward for time and effort invested.
 

the baron

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I also am not anti-rehydration but it is not essential with standard dried yeasts as the cell loss is not as large as was believed so its simple sprinkles for me if you want to re-hydrate and its part of your process do but it is not essential.
Now growing yeasts from small amounts is a different thing and another string to a brewers bow. I also save my yeast and re-pitch but do it in a simple way without washing and use within a month generally
 

Cwrw666

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Exactly. And since we can reuse the yeast by top-cropping or pitching on the cake, after the initial pitch, the issue becomes academic. Except with recipes (usually for lagers) which say pitch two packets of yeast. If I were anti-rehydration, I think I'd pitch into a half batch first to build up enough yeast for a full batch. I do this anyway, when I'm recovering yeast from a bottle since it's a way of building a starter that gives some immediate reward for time and effort invested.
I'm also not anti-hydration. If someone wants to do it that's fine by me - but I'm not going to bother.
Interestingly with lager yeasts. I've only ever used CML Hell which has had excellent results pitched both at the lower end of it's temp. range (12c) and at it's higher (18). In the former I used 2 packets as instructed, in the latter just 1 (also as instructed).
 

the baron

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the info on the geterbrewed vid is not best but if you watch the "Pitching Best Practices for Lallemand Dry Brewing Yeast" video it is much clearer as it comes from recent R&D and shows the pluses and minuses. It also shows how to re-hydrate properly albeit in there words not essential due to the recent R&D.
Again sorry I can not make it easy for you but my Copy and paste and producing a link crashes my computer
 

An Ankoù

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Clearly "anti-rehydration" was an unfortunate choice of words. I really meant "those who prefer to sprinkle the yeast directly into the wort", but it sounds a bit like trying to avoid saying "Voldemort". :laugh8::laugh8::laugh8:
 

the baron

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When I used the word Anti-hydration I was meaning myself and not stating a it is a absolute (so no offence taken)as I have tried it before and just found it too much of a pfaff with no better results.
I would probably use it on a high ABV beer or 2 packets but I generally fall into sub 5% beers and after watching the Lallemand vid it has confirmed my thoughts anyway
 

chthon

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There is also a third school, one which I tried and worked well: do not cool your wort completely down to its pitching temperature, but go to 25-28°, then sprinkle your dry wort on top of it. Your ambient temperature needs to be lower, so that your wort can keep cooling. Worked well, I had lively fermentation in less than eight hours. And that was actually underpitching at 0,6 instead of 0,75.
 

MrRook

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Yeast companies want you to be happy with their product. If direct pitching didn't give good results they wouldn't recommend it.
 

Griff097

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never seen it on a yeast packet before, how long have you been doing it that way then mate? I must admit I do like the sound of it and am definitely going for it on my next brew 👍
I have been doing it this way as long as I have been AG brewing looking at the yeast pa ket today I realised where that advise came from, it was a combination of the yeast manufacturers (water at 30c) and my mates advice wort at 30c, you know when you have done something for so long you no longer read the instructions and assume it was from there Lol
Most of my brews stop at the expected gravity, some over attenuate and I have only had two in all that time that have stopped short, so maybe that was down to rehydration/yeast age?
 

the baron

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That's exactly what Lallemand have said in the vid Griff that if you use it as part of your process feel free to carry on but the yeast cell loss when dry pitching is not what it has always been thought it was and that it was so much lower than previous that it made no real difference.
This was done in their recent Research and Developement.
I just dry pitch now and have done for a long time as I found no difference when re-hydrating.
So do which ever suits your process but debunks the ones who say you have to do it, it is a preference but you will get the same result according to their R&D
 

moto748

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There is also the much derided point: "When all else fails, read the instructions on the packet". 😀

If the packet says, just sprinkle it on, it's hardly going to be disastrous, is it? I only made a starter once, I think, and that was only with warm water, again, as per the packet.

That said, just cos it says so on the packet, doesn't necessarily make it the *best* procedure, I suppose. When I'm making (yeasted) bread, the easyblend yeast packets always say, just mix direct into the flour. I never do that. I always make a starter with sugar and water in the traditional way, cos i firmly believe it is *better*. Seems to me it's an appropriate parallel.
 

moto748

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There's also the question of how much yeast to use. Making a 16 litre batch of stout the other day, i suddenly realised that I only half a packet of US-05 left. What to do? Make do with half a packet, or try some other yeast, or a mixture of two? In the end I opted for just using half a packet (I regularly use half a packet for 11 litre brews). it seems to working perfectly well.

Conversely, I have a pack of Lallemand NEIPA yeast in the fridge. Normal size 11 g packet, but it says, pitching rate of 1 g/litre. That implies two and half packets for a 23 litre batch! You'd think yeast would be packaged in "enough for a normal batch size" quantity.
 

dad_of_jon

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mj recommend a rehydrate, whereas llalemand with the kviek voss says they've had better results not re-hydrating.


 

dad_of_jon

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When I used the word Anti-hydration I was meaning myself and not stating a it is a absolute (so no offence taken)as I have tried it before and just found it too much of a pfaff with no better results.
I would probably use it on a high ABV beer or 2 packets but I generally fall into sub 5% beers and after watching the Lallemand vid it has confirmed my thoughts anyway
yup - given my beers are usually at the higher end of the abv range for most of the yeasts I use, I rehydrate. Plus you also get a bit more headroom if the yeast hasn't been stored optimally.
 

venkman100

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Well, up to my last brew I just sprinkled in my US05 or whatever and fermentation has kicked off about 24 hours later. My last brew was a Raspberry Wheat beer. I had read about using wort to rehydrate yeast. So, during the boil on brew day I took off some wort in an erlenmeyer flask, let it cool and pitched my CML Gretal yeast. The yeast loved it. A little over an hour later I pitched a flask of healthy looking yeast . Later that night the airlock was going and the beer has turned out very nice.
The big question, did I do right or wrong? Was i lucky? Is it a big no no.
Can't remember where I read the article though.....
 

Griff097

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Well, up to my last brew I just sprinkled in my US05 or whatever and fermentation has kicked off about 24 hours later. My last brew was a Raspberry Wheat beer. I had read about using wort to rehydrate yeast. So, during the boil on brew day I took off some wort in an erlenmeyer flask, let it cool and pitched my CML Gretal yeast. The yeast loved it. A little over an hour later I pitched a flask of healthy looking yeast . Later that night the airlock was going and the beer has turned out very nice.
The big question, did I do right or wrong? Was i lucky? Is it a big no no.
Can't remember where I read the article though.....
Thats generally my experience, but after reading this thread it makes me feel what I am doing is wrong, usually within 24 hrs it's fermenting furiously.
 
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