Hydrating yeast

[1eyedjack]

My kit instructions advise me to "hydrate the yeast" in a sterile cup of warm water (30 to 40 degrees) before pitching it into the wort (at below 25 degrees). Eh? What's that all about? Anything wrong with stirring the dried yeast directly into the wort? That is what I did before, but I am only starting out.

 

[bolty]

Dried yeast will suck up pretty much ANYTHING into their cells as they rehydrate. This means with water, they just rehydrate, but with wort this includes sugars that I believe can crystalise inside the cells and burst them. This will not happen to all the cells, but if you rehydrate with water you get more viable cells.

I have also notices a shorter lag time as you are pitching a slurry, which will go through the froth and straight into the wort, ready to work.

 

I don't know if "bolty" is right or wrong.
I do know that a lot of HBers, my self included, just pitch the dried yeast directly into the wort.
A yeast head develops within 24 hours!

 

[mr_spin]

I think the general idea with rehydrating is to get the yeast working ASAP without delay so to minimise the risk of infection before the yeast has kicked in. Dried yeast takes longer to get going.

 

[BroughcliffeBrewer]

John Palmer has this to say, seems reasonable to me and I always do this with dried yeasts that I use (Windsor, S-04 and US-05), only takes a minute to do while you're boiling your wort.

Preparing Dry Yeast
Dry yeast should be re-hydrated in water before pitching. Often the concentration of sugars in wort is high enough that the yeast can not draw enough water across the cell membranes to restart their metabolism. For best results, re-hydrate 2 packets of dry yeast in warm water (95-105°F) and then proof the yeast by adding some sugar to see if they are still alive after de-hydration and storage.

If it's not showing signs of life (churning, foaming) after a half hour, your yeast may be too old or dead. Unfortunately, this can be a common problem with dry yeast packets, especially if they are the non-name brand packets taped to the top of malt extract beer kits. Using name brand brewers yeasts like those mentioned previously usually prevents this problem. Have a third packet available as back-up.

Re-hydrating Dry Yeast
1. Put 1 cup of warm (95-105F, 35-40C) boiled water into a sanitized jar and stir in the yeast. Cover with Saran Wrap and wait 15 minutes.
2. "Proof" the yeast by adding one teaspoon of extract or sugar that has been boiled in a small amount of water. Allow the sugar solution to cool before adding it to the jar.
3. Cover and place in a warm area out of direct sunlight.
4. After 30 minutes or so the yeast should be visibly churning and/or foaming, and is ready to pitch.

Note: Lallemand/Danstar does not recommend proofing after rehydration of their yeast because they have optimized their yeast's nutrional reserves for quick starting in the main wort. Proofing expends some of those reserves.

 

[BarnsleyBrewer]

I use wort that's been cooled down, never had any issue's :hmm:

BB

 

[Aleman]

John Palmer has this to say, seems reasonable to me and I always do this with dried yeasts that I use (Windsor, S-04 and US-05), only takes a minute to do while you're boiling your wort.

Unfortunately what John doesn't say is that the rehydration temperature is strain dependant. The Danstar yeasts need 35C, but Fermentis SO4 (Ales) need 27C and S23 (lager) need 24C. . . . Proofing is a complete waste of time too . . . I've had named yeasts not proof . . .and yet they ferment the main batch just fine.

It is best practice to rehydrate the yeast at the correct rehydration temperature for the strain being used as it results in more viable cells . . . Perhaps as much as 50% more than 'sprinkling' but with the 11/12g sachets of yeast that we are using you will 'get away' with just sprinkling over the wort . . . . I always rehydrate

 

[artyb]

ive made yeast starters, with room temp fruit juice,nutrient,sugar,
and popped it in a warm place,always takes off well,
often i dont bother and just sprinkle..

 

[Sean_Mc]

I've started to hydrate rather than just dry pitching after similar thread Bolty posted on.
The reason is that the liquid will go straight through the froth from aerating