Rehydrating The Yeast

[SearlyPron]

Hi all,

I've just put down my fourth batch after three very successful brews thus far (although the Morgan's Amber went a little down hill towards the end....). In each of the previous batches I've sprinkled the yeast on top and stirred it in just before sealing the fermenter, but this time round thought I'd try rehydrating the yeast before adding it, as I've read that this allows the yeast to really hit the ground running so to speak.

Anyway, I think I made a bit of a mess of it to be honest. I added the yeast to some luke warm water in a cup and since most of it was sitting above the water level, I gave it a bit of a stir. What I ended up with was a gluggy mess which was difficult to get into the fermenter without needing a fair bit of scraping of the cup. I was pretty concerned that I'd managed to kill most of the yeast.

A couple of days into the ferment, there's plenty of froth on top and the air-lock seems to be bubbling away quite happily, so I'm feeling much better about it, but can anyone give me some tips on the best method of rehydrating yeast?

Do I need to use a bowl with a large surface area rather than a tea-cup?

Any advice much appreciated. (It's a European Lager with saf-lager yeast if that helps).

Thanks!

 

[Interloper]

Hi all,

I've just put down my fourth batch after three very successful brews thus far (although the Morgan's Amber went a little down hill towards the end....). In each of the previous batches I've sprinkled the yeast on top and stirred it in just before sealing the fermenter, but this time round thought I'd try rehydrating the yeast before adding it, as I've read that this allows the yeast to really hit the ground running so to speak.

Anyway, I think I made a bit of a mess of it to be honest. I added the yeast to some luke warm water in a cup and since most of it was sitting above the water level, I gave it a bit of a stir. What I ended up with was a gluggy mess which was difficult to get into the fermenter without needing a fair bit of scraping of the cup. I was pretty concerned that I'd managed to kill most of the yeast.

A couple of days into the ferment, there's plenty of froth on top and the air-lock seems to be bubbling away quite happily, so I'm feeling much better about it, but can anyone give me some tips on the best method of rehydrating yeast?

Do I need to use a bowl with a large surface area rather than a tea-cup?

Any advice much appreciated. (It's a European Lager with saf-lager yeast if that helps).

Thanks!

On the Nottingham Danstar yeast pack they advise lukewarm water for 15-30 minutes and they are very specific that you should not stir it until after then.

You'll find most drops to the bottom as it froths and foams.

They then say to stir in anything that hasn't dissolved after this 15 min period.

You should have a nice creamy slurry by then, so stir and pitch.

 

[braufrau]

This is what fermentis say ...

Re-hydrate the dry yeast into yeast cream in a stirred vessel prior to pitching. Sprinkle the dry yeast in 10 times its own weight of sterile water or wort at 27C 3C. Once the expected weight of dry yeast is reconstituted into cream by this method (this takes about 15 to 30 minutes), maintain a gentle stirring for another 30 minutes. Then pitch the resultant cream into the fermentation vessel.


I guess instead of a stirred vessel you could just stir it every now and then with a sanitised spoon, or put it in a jar you can shake.

They then go on to say


Alternatively, pitch dry yeast directly in the fermentation vessel providing the temperature of the wort is above 20C. Progressively sprinkle the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes and then mix the wort e.g. using aeration.


http://www.fermentis.com/FO/EN/pdf/SafbrewS-33.pdf

 

[Brewtus]

I get half a cup of the same water, eau d'faucet, I use for mixing with the kit in a glass that has been processed in a mechanical cleansing installation (AKA Dishwasher) before I put the kit can in boiling water. I aerate the water first by pouring from the tap and put the yeast in and cover it with a saucer. After 10 min I might swirl it a little if needed. Once the wort is ready I swirl it again and tip it in. By this time it is creamy on top. I then rinse the glass with water to get the last of the yeast out.

Always had a good result. Is it better than just sprinkling the yeast on? Who knows but it gives me something more to fiddle with on brew day so I can kid myself I am crafting an individual creation.

 

[Bribie G]

I just took delivery of some Fermentis brand safale and saflager yeasts from CraftBrewer. They both specify just to sprinkle on surface of wort. A recent ESB with a Saflager specifically said to dry pitch and NOT to stir into the brew.

A month ago I did two absolutely identical Coopers Lager with their 'normal' yeast. Cultured one for an hour in a sterilized glass bowl under clingwrap with some warm water and some honey. Frothed up nicely. I pitched the other sachet dry - and not stirred - as an experiment.

They both fermented and attenuated exactly the same.

I haven't used a Nottingham Yeast yet, but will be doing so soon as I'm going to explore some English Bitters, but for my regular cookin' kits & bits I personally will just dry pitch.


Edit: As Buttered said above, however, if I got into a situation where I suspected that the yeast was old (Hypothetical: BILO clearing out a heap of dodgy looking kits for half price) I might rehydrate to check for viability. However since starting to use Saflager etc I'm starting to acquire a few Coopers and Morgans kit-top sachets that I keep in my beer fridge, so always have a couple of trusty yeasts in stock.

 

[Interloper]

I haven't used a Nottingham Yeast yet, but will be doing so soon as I'm going to explore some English Bitters, but for my regular cookin' kits & bits I personally will just dry pitch.

I figure if I am forking out for a quality yeast I will follow the manufacturers instructions and they are specific about rehydrating it first. I use the Nottingham a lot as I love stouts and ales. I have harvested it and brewed up startes from the trub and this always gives you good value for money on your yeasts.

 

[brettprevans]

this has been fairly well covered before. many AHB threads on redydrating yeast.

1. Dry yeast is fine to pitch without hydrating. The packets say so. If you want to rehydrate go ahead. The packets also support that.
2. if doing high gravity beers or cold fermenting lagers, then the amount of yeast and the healthyness of yeast you need is more.
- either chuck in 2 packets of dry yeast
- rehydrate and make a starter
3. Ross (craftbrewer) doesnt bother rehydrating. Ive never bothered in any of my brews. all came out fine.
4. 2L PET bottles are great for hydrading yeast and making starters becauser you can easily steralize them and if you make a starter you can shake about with no mess.
5. Butters' the tip about 'feeding' the yeast a little malt or dex is good. It gives them a little wake up and gets them going.
6. if its a regular ale or something being brewed at normal temps I personally wouldnt bother.
7. Stir your yeast in or sprinkle on top. your choice. I sprinkle on top evenly. Ive tried both. both work. personal preference.

 

[Benniee]

They both fermented and attenuated exactly the same.

Could be good to do a side-by-side taste test to see if they both taste the same too.

As for pitching dry on top of the wort - one thing to be careful of is if you have to carry the fermenter to it's final position after you've pitched the dry yeast. I did this once and wasn't as gentle as I should have been and ended up with a bit of the dry yeast stuck to the side of the fermenter from the sloshing that went on inside.

Fermentation still went as planned and beer tasted fine, I justed missed out on that little bit of yeast that got stuck on the side.

I will only rehydrate dried yeast if I think the packet has a little too much age on it, or I suspect it's been stored in less than ideal conditions.

Benniee

 

[rich_lamb]

Ive never bothered in any of my brews. all came out fine.

You'll hear this a lot, and it's probably true, but the suggestion is "could they have come out better with the alternative"

Searly, you did pretty much the right thing - don't worry. You can't squash the yeasties with your spoon.

Everybody's right. You can happily sprinkle straight onto wort - there's plenty of viable yeast in the packs and if you're in doubt you could use two packs.

I personally take the manufacturer's advice and rehydrate. I did all sorts of dodgey proofing and making small starters originally and I documented all my fermentation results. All things being equal (which they rarely are) I get far more consistent fermentation now, just based on the stats.

There is good science to rehydrating - the osmotic pressure in the wort will force sugars into the yeast cells before they can assimilate their cell walls. In theory this can cause them to behave at less than their best - based on George Fix's description in "Principles of brewing science". The manufacturer seems to believe it. And since it's so easy I wonder why you wouldn't do it (and believe me, I'm lazy).

 

[tdh]

Yeast:water = 1:10
Sprinkle yeast into 35*C water
Leave for 20 minutes
Add 10% increments of wort every 3 minutes to attemperate
Pitch

tdh