Rehydrating Dry Yeast - Conflicting Advice

[haysie]

The rehydration will cetainly give a shorter lag time as others mentioned,, that in itself is a good thing. Sure your double handling so hence you have a double chance of germies, but you should know where your at with your sanitation etc.
The argument underpitch/overpitch, I dont get the underpitch thing at all. Bollucks.
I would overpitch fresh yeast any day of the week than underpitch.

 

[Sammus]

I meant my other post, where I explained that overpitching is worse than underpitching based on my experience doing them both. In my experience this is how it is. Maybe I used the term empirical wrongly? but as far as I know (and wiktionary) empirical means based on experience. I'd send you my brain so you can extract my recollections of the beers I've tasted, but I want to live a little while longer still.

 

[buttersd70]

It's way to much info to even try posting, but if you have Brewing Science and Practice, chapter 13 (in general) and 13.3.1 (more specifically) discuss the problems of both under and over pitching. Whilst it doesn't make a definitive statement that one is better/worse than the other, in so many words, the general gist of it (or at least my interpretation of it) is that, particularly in relation to ales (but relating to lagers as well), overpitching is, indeed, the worse of the two evils.

Correct pitching rates are obviously desired....but then, what is correct? Fix's numbers, for example, are quite different to Geigers....both sources are just as credible, but disagree with each other (as happens with so many things, both brewing and non brewing :lol: ). : so the layman has to make a decision based on relevant information as to which expert (and these people are true experts) to believe.

summary: buggered if I know, cos the information is conflicting.

 

[Thirsty Boy]

over pitching can lead to a couple of flavour issues.

More yeast can mean more diacetyl production, higher acetylaldehyde levels and can also lead to a lack of flavour development in the beer.

Read Jamil's stuff carefully and you will see that his pitching rates are worked backwards from the assumption that optimum flavour is achieved in a beer when the yeast has had to multiply a certain number of times (I seem to recall it was 3 or 4) in order to get to the right levels. So you pitch X number of cells, and they double 3 times - and that gives you the optimum flavour profile.

Jamil's pitching rates for dried yeast - I believe but am not sure - assume that you have re-hydrated to manufacturers instructions, because the whole point of re-hydration is to prevent cell mortality on pitching. So Jamil wants you to pitch X number of live viable cells... not X minus however many die when you toss them dry into a sugar solution.

Thats how I understand it works anyway

TB

 

[drsmurto]

I meant my other post, where I explained that overpitching is worse than underpitching based on my experience doing them both. In my experience this is how it is. Maybe I used the term empirical wrongly? but as far as I know (and wiktionary) empirical means based on experience. I'd send you my brain so you can extract my recollections of the beers I've tasted, but I want to live a little while longer still.

Nowhere in this thread have you explained anything. Its only now that you have actually expanded on your statement.

 

[manticle]

I must be behind the 8-ball. I always assumed rehydration would be at intended ferment temps and that seems to work fine for me. I actually never realised that some suggest hydrating so high.

 

[Sammus]

Nowhere in this thread have you explained anything. Its only now that you have actually expanded on your statement.

I'm sorry. What about post #37? I thought that expanded on my statement too. It did if by that you mean told of my experience and why I feel the way I did.

 

[acoulson]

Yeast doesn't dissolve, it is in suspension.

Two very different beasts.

Y

Yes, your right. How silly of me. What's the correct noun? Suspensibility? :unsure:

 

[manticle]

I think it's suspendinggednessness

 

[Snow]

I think it's suspendinggednessness

Nah I think it's suspendication

 

[thylacine]

overpitching is worse than underpitching


Both as bad as each other. With liquid yeasts underpitching is easier to achieve than overpitching.

tdh

"Basic Brewing" & BYO magazine are currently experimenting the pitching of yeast. ie. under, recommended & over.

Their previous experiment (all brewers invited to participate & forward individual results) explored 'how long to leave one's beer on the yeast cake'. eg. up to one month (some went longer...)

 

[tdh]

Aren't we exploring these paths? Look passed the babble and add 2c worth, not more babble.

tdh

 

[lespaul]

I have a yeast starter going now, or over the last couple of days, and it was up around the 36 degree mark today thanks to the melbourne weather. there is a kind of sour smell coming from inside the bottle (origionally 1.035) and im not sure if this is from the heat and shaking the bottle all day while brewing, or its infected or whats going on.
I poured off the beer and it smells like normal yeast. Is it worth doing the final starter or it this pretty much wasting my time and i should just go buy another 2 packets?
Cheers

 

[manticle]

In my experience, wort that is fermented out warm and shaken (as I might do in a fast ferment test) smells and tastes horrible. If the yeast smells OK, I would add some more wort, treat it gently this time and if she smells and tastes OK, go for it.

 

[davo4772]

Just been reading White/Zainasheff. I must say, never thought I would buy a book on fungus and then feel the need to post about it on the internet.

Anyway,

They make a couple of points. Sprinkling yeast directly onto wort will kill half of the cells.

As to rehydration, follow the manufactures instructions as the temperature can vary. Do not ever rehydrate in water that is too cool as again will kill half the cells.

Still trying to get me head around cell counts and starters, but that is another thread.


Cheers

Dave

 

[Tanga]

Wow!

I had no idea population size would make a difference - let alone so much of one. Anyone got links to some more info on how to work it all out? How much difference in the taste does it really make? I thought it was just time to start / completion.

 

[mwd]

Seems a bit odd the higher water temperatures required to rehydrate yeast but cannot argue the facts sure the Manufacturer knows the product much better than the users.