Rehydrating yeast

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the baron

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Well it looks like another Urban myth debunked just like the grassiness in dry hopping.
I am beginning to think that some of these things we have come to believe over the years are created to sell items by manufacturers with no more than anecdotal stories and even some of us brewers convincing ourselves that we have seen improvements in our actions that have not been there. can you remember the one that " Starsan is no good if it goes milky" how many more are there out there.
Maybe I'm becoming a Flat Earther!!!
 

andrewrjones

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I rehydrate using the same water as I brew with, using a mason jar as described here, but with the 100ml of water suggested on the packet: Rehydrating Dry Yeast - Homebrew Notes

I brewed Thursday and the following morning it was looking like this, so seems happy! On Friday still lots of activity. Right now (Saturday evening) very little activity, presumably mostly done.

Like the OP was a bit confused/put off by the instructions, but what I did seems fine. Don't know why they make it sound so complicated.
 

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trueblue

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I would advise any brewer that wants to improve/take their beer to a higher level to read the yeast book. To me the most important book available to the home brewer.
 

the baron

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I think the yeast book may be a good read especially for liquid yeasts and the like but the thread is regards rehydrating dried yeasts or not and in this case Lallemand has come out and said there is nor discernible difference between rehydrating and not and rehydrating is only a matter of personal process preference
 

An Ankoù

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I am beginning to think that some of these things we have come to believe over the years are created to sell items by manufacturers with no more than anecdotal stories and even some of us brewers convincing ourselves that we have seen improvements in our actions that have not been there.
I'm not so sure. Don't some recipes, especially lagers, say pitch 2 packets? They' would sell more items and make more money this way, not less.
Lallemand has come out and said there is nor discernible difference between rehydrating and not and rehydrating is only a matter of personal process preference
I watched the video and I just don't buy it. Sure, he claims Lallemand say there's little difference. Do they? He showed us how to rehydrate (without any kind of cover on the flask) and then reiterates that it doesn't make a difference, but where was the comparison? He didn't pitch his starter into a batch of wort and then sprinkle another batch of wort to compare what happens. That's not science.
Rehydrating is done at 35C. Do we usually sprinkle a wort with dry yeast with the wort at 35C? What's the significance of 35C?- It's the optimum temperature for rehydration of many ale (not lager) yeasts so sprinkling a batch of wort of 20C is less than optimum.
Sorry. This just isn't science it's bolllocks.
It may possibly be the case that there's not much difference, but this video doesn't demonstrate it.
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.
I'll carry on rehydrating.
 

trueblue

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I think the yeast book may be a good read especially for liquid yeasts and the like but the thread is regards rehydrating dried yeasts or not and in this case Lallemand has come out and said there is nor discernible difference between rehydrating and not and rehydrating is only a matter of personal process preference
The yeast book goes into a lot of detail about dry yeast. The reason I think brewers should read it is it gives you an understanding of how your yeast works put in a way even people like me can understand. Although one of the authors is one of the men behind Whitelabs it is not a book promoting their product in fact it goes into a lot of detail about getting multiple brews from their packs and maintaining your own strain.
 

Tommo 2

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I'm not so sure. Don't some recipes, especially lagers, say pitch 2 packets? They' would sell more items and make more money this way, not less.

I watched the video and I just don't buy it. Sure, he claims Lallemand say there's little difference. Do they? He showed us how to rehydrate (without any kind of cover on the flask) and then reiterates that it doesn't make a difference, but where was the comparison? He didn't pitch his starter into a batch of wort and then sprinkle another batch of wort to compare what happens. That's not science.
Rehydrating is done at 35C. Do we usually sprinkle a wort with dry yeast with the wort at 35C? What's the significance of 35C?- It's the optimum temperature for rehydration of many ale (not lager) yeasts so sprinkling a batch of wort of 20C is less than optimum.
Sorry. This just isn't science it's bolllocks.
It may possibly be the case that there's not much difference, but this video doesn't demonstrate it.
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.
I'll carry on rehydrating.
Couldn’t agree more , of course most of the home brew retailers are going to say just sprinkle on the wort it makes no difference , they want to sell as much product as they can , can’t blame them for that, but in my mind and experience it makes a big difference and won’t be changing my method any time soon either. Like I said before it all looks really complicated this rehydration method , but it really ain’t .
 

Griff097

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What is the specific isue with pitching into a small volume of cooled wort as per the rehydrating instructions on many yeast packets and how does using cooled water differ?
 
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Tommo 2

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What is the specific isue with pitching into a small volume of cooled wort as per the rehydrating instructions on many yeast packets and how does using cooled water differ?
The water is boiled first then cooled to 35c and of course sanitation is paramount, when sprinkling straight on to the wort they tell you always pitch at 20c or just below so there’s a massive difference at pitching temperatures and my opinion is it’s shocks the yeast direct pitching does so that’s why some of the cell obviously die
 

Griff097

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The water is boiled first then cooled to 35c and of course sanitation is paramount, when sprinkling straight on to the wort they tell you always pitch at 20c or just below so there’s a massive difference at pitching temperatures and my opinion is it’s shocks the yeast direct pitching does so that’s why some of the cell obviously die
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?
 

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To be honest I have never tried that before in all the years I have been brewing , sounds like a plan and I will do one that way on my next brew, can’t see why not as long as the vessel used for starter is sterilised and ready to go and then covered whilst cooling. Maybe someone on the forum has tried it this way and will comment on good or bad thing to do.
 

Griff097

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To be honest I have never tried that before in all the years I have been brewing , sounds like a plan and I will do one that way on my next brew, can’t see why not as long as the vessel used for starter is sterilised and ready to go and then covered whilst cooling. Maybe someone on the forum has tried it this way and will comment on good or bad thing to do.
That's the way I always do it and I learned it from the instructions on a yeast packet, I thought it was the norm?
 

dad_of_jon

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Once the water is boiled not much chance of any chlorine being in it anyway ; and the whole process of rehydration is much easier than it sounds ; have done it for donkeys years with no problem at all and with great results
we have chloromine in our water supply that survives a boil.
 

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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?
The theory is that using pure wort will cause a large osmotic pressure between the inside of the yest cells and the liquid outside, which can cause yeast death. The ideal situation would be making up a solution of weak wort at 30-35 C, but water is better than pure wort.
 

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That's the way I always do it and I learned it from the instructions on a yeast packet, I thought it was the norm?
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 👍
 

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Well it looks like another Urban myth debunked just like the grassiness in dry hopping.
I am beginning to think that some of these things we have come to believe over the years are created to sell items by manufacturers with no more than anecdotal stories and even some of us brewers convincing ourselves that we have seen improvements in our actions that have not been there. can you remember the one that " Starsan is no good if it goes milky" how many more are there out there.
Maybe I'm becoming a Flat Earther!!!
DON’T SQUEEZE THE BAG :)
 

Tommo 2

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The theory is that using pure wort will cause a large osmotic pressure between the inside of the yest cells and the liquid outside, which can cause yeast death. The ideal situation would be making up a solution of weak wort at 30-35 C, but water is better than pure wort.
Ok thanks for that Mmmbeer maybe stick to the way I’ve always been doing it then , thought there might be a reason 👍
 

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 will check the brew fridge tomorrow to see what make it was, but the only instructions I have seen are pitch direct or cooled wort.
That book on yeast sounds interesting, will have a look for that.
 
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