Revisiting the rehydrate or not debate

[andylanc1975]

I'm a few days in to brewing my Milestone IPA kit and just thought I'd reignite the to rehydrate or not the yeast.

In the past I've been a lazy little sausage and just sprinkled them on top and let nature take it's course. And within 48 hours, the airlock has been bubbling and the krausen has risen and the beer eventually brewed.

With this kit, I actually read the blurb on the yeast and did the whole 1/4 tsp of sugar, warm water, leave it for 15 mins, give it a good stir, mix with 250ml of diluted wort, leave for a few minutes then add to the FV... To use youth vernacular OMG!! Within 2 hours of putting the lid on the FV, the airlock was bubbling like a loon!

Took a gravity reading today and it's already down around 1014 from a 1040 starting point, this could be the quickest fermenter I've seen.

So I'm changing my vote from don't rehydrate to I rehydrate every time (from now on!)

 

[alanywiseman.]

My problem is that some yeasts do not come with instructions on how to rehydrate (mostly those from kits mind). Yeasts sometimes need rehydrating at different temps, with/without sugar etc.

If I am told to I do it but otherwise I just sprinkle. Mind you I would have thought rehydration would be the way to go due to less stress for the yeast.

 

[darkonnis]

I suppose its a matter of opinion on what you want to do, but Chris White reckons you are better to hydrate them in 100ml of boiled(and cooled) water only, as in a dry state they cannot control what comes in and out of their membranes and the sugar kills/damages them (roughly 50% suffer if you pitch them straight in). Once hydrates pitch immediately or for higher gravity beers its something like a litre with a cup of dme to allow them to multiply (gravity at 1.040 or less) then when its finished decant most of the liquid, swill the yeast and then pitch it straight in...
For me, you don't start a mulitmillion dollar company selling yeast to breweries of all levels and homebrewers unless you know what you're talking about.

 

[jamesb]

Just to throw a spanner in the works, I've been reading various brewing (commercial) papers that say if you do hydrate your dried yeast then don't aerate your wort.

I throw this open to the floor...

 

[RobWalker]

dried, rehydrated, smack packs, vials, it all works if you chuck it in.

I would be more worried about a quick, active fermentation if I was fermenting with the lid off/opened. Under airlock, I can't see it mattering.

"It makes good beer."

 

[TheMumbler]

Just to throw a spanner in the works, I've been reading various brewing (commercial) papers that say if you do hydrate your dried yeast then don't aerate your wort.

I throw this open to the floor...

Interesting ... two things:

1) Is there any explanation for why it is better to not aerate?
2) Does it really change anything for homebrewers who struggle to get enough oxygen into the wort without using an oxygen stone (as far as I can remember from reading Yeast) anyway?

dried, rehydrated, smack packs, vials, it all works if you chuck it in.

I would be more worried about a quick, active fermentation if I was fermenting with the lid off/opened. Under airlock, I can't see it mattering.

"It makes good beer."

Obviously so long as you are happy with the results then you are winning. That said how stressed the yeast is is supposed to have an impact on the flavours that you get in the beer so if you are after more control of flavour it potentially does matter.

 

[johnnyboy1965]

Dried Yeast...This is coated with a preserving substance that is broken down in warm water. If you rehydrate your just breaking this coating down before you pitch. therefore it gets to work straight away.
Oxygenating your wort...Yeast goes through a few stages before it starts to make alcohol...First of all it will consume all the dissolved O2 ( note dissolved ) you cannot dissolve 02, in wort, by whisking. You can dissolve some 02 but only about 10% (some is better thatn none). After this stage the yeast will look for something elase to "eat"....fermentable sugars.
Re-hydrate dried yeast ? yes
Feed re-hydrated yeast ? cant see the point
Sprinkle on top...Why not, Itll do its thing sooner or later

Using dried yeast? It convenient.
Harvest your dried yeast and you have a liquid yeast

 

[darkonnis]

See, according to "Yeast" when dried their membranes aren't upto much, so you do them no favours at all by putting them straight into a sugary solution, once rehydrated, they're ready to rock and roll however. Yeast reckons you kill 50% or so by not hydrating, whatever gives you best results though i guess. Personally my yeast do awesomely when hydrated.
You are right about the oxygenation though, you can only get between 10 - 30% by shaking and whisking, and I honestly think you'd have to be going some to get anywhere close to even 20% let alone 30.

James, can you say where you got that from cause that doesn't sound right. not saying it isn't, but I can't think of a reason why hydrating would mean not aerating. Especially if you use liquid yeast, as most breweries do, and they aerate their worts...

 

[oldstout]

.......... as in a dry state they cannot control what comes in and out of their membranes and the sugar kills/damages them (roughly 50% suffer if you pitch them straight in)

How would they know that :wha:


Seriously


Yeast: '' Ooooh the bug*ers dropped me straight on top again, I'm tellin' ya me membranes can't take much more of this..... OOOooof ya f**ker that sugars absolutley knacking....'' etc

Haway man, it's yeast :whistle:

It'll eat ya sugar and turn it into alcohol one way or the other


If ya feel like hydrating it - and I have done it meself - crack on :thumb:

But honestly, it's not rocket science, it's yeast :lol: :lol: :lol:

:thumb:









Lights fuse...... :whistle:



Stands well back....... :hmm: :hmm: :hmm:







:drink:



:

 

[darkonnis]

Its as much fun or science as you want it to be , how would they know...? dunno they set up a rather successful company by selling the stuff so i presume they'd know what they're on about :ugeek: I imagine they probably put some wort on a plate with some yeast and look at it through some scope or other. I get better results when hydrating, so I'm happy with the advice :)

 

[jonewer]

I dry pitch my yeast. Why?

1. It works
2. Less chance of contamination by faffing about with it.

 

[andylanc1975]

Well after an enforced absence off this site (how dare work make me too busy to have a proper dinner time!!), I'm glad to see this post hasn't become a battle ground!

Some good points both for and against, so thank you all for taking the time to comment, hugely appreciated :thumb:

 

[shearclass]

reignite the to rehydrate or not the yeast

I didn't realise there was a debate. I assumed everyone thought ti was best practice to rehydrate?

 

[orlando]

reignite the to rehydrate or not the yeast

I didn't realise there was a debate. I assumed everyone thought ti was best practice to rehydrate?

There isn't, it is.

 

[johnnyboy1965]

Then why do manuacturors (Im sure theres a few letters missing there) state "sprinkle on top" ?

 

[Vossy1]

How would they know that

Control tests and viability counts. You can actually do this at home with microscopes, if you were inclined :grin:
From my experience
sprinkled on foam...delayed take off
sprinkled on wort (foam parted) faster take off
rehydrated in sugar solution...much faster than dry
rehydrated in water...as for sugar
liquid, as per rehydrated
slurry (more yeast)...faster than all the above

Differences in pitching temps very important...cold yeast warm wort and visa versa not good.

 

[Aleman]

Then why do manuacturors (Im sure theres a few letters missing there) state "sprinkle on top" ?

To keep it simple for those making up kits.

Edited in the interest of forum harmony.

 

[theboytony]

Then why do manuacturors (Im sure theres a few letters missing there) state "sprinkle on top" ?

Not all do, if I remember right it is the manufacturers of the budget beer kits that put that in the instructions, and while it might make good beer it could always be better. I suppose if they put great yeast in the budget kits and told people how to use it properly then there wouldn't be as much of a difference when people buy their more expensive kits... :drink:

 

[johnnyboy1965]

Fermentis Safbrew WB 06...Instructions...."Sprinkle into wort"
Why would a company spend thousands of pounds in developing their product, for "us" to come along and do something differently?

 

[oldstout]

How would they know that

Control tests and viability counts. You can actually do this at home with microscopes, if you were inclined :grin:
From my experience
sprinkled on foam...delayed take off
sprinkled on wort (foam parted) faster take off
rehydrated in sugar solution...much faster than dry
rehydrated in water...as for sugar
liquid, as per rehydrated
slurry (more yeast)...faster than all the above

Differences in pitching temps very important...cold yeast warm wort and visa versa not good.

That's interesting Vossy1, but yeah you're basically right...

Home? Check.

Yeast? Check.

Microscope? Check.

Lack of inclination to fanny on with yeast instead of simply sprinkling on top? Check :thumb:

:

Edited in the interest of forum harmony.