Hydrating yeast

[ryderkellan]

Apologies if this has been asked many times before. I get the gist of how to rehydrate yeast, but instructions I've seen refer to sterilized water. How do you go about this? Boil and leave to cool for...ages?

 

[marshbrewer]

Yes, boil then cool to rehydrating temp. You don't need much, so it cools down pretty quickly.

 

[Hoddy]

Just boil your kettle and the put the right volume into a jug (when it’s freshly boiled and red hot) and cover with some cling film and leave for 4hrs to cool to room temp.

When it’s ready mix your yeast with the water and leave for 20 mins.

Then just pitch it. Happy days

 

[Drunkula]

Rehydrating about 35c is better. You only need to get the water to 65c to pasteurise it. I never sterilise the water beacause after doing so many kits just adding water to those it seems pointless.

 

[Bigcol49]

Hi @ryderkellan
You don't need much water to rehydrate yeast. I boil the kettle, fill a cup, pour out everything that I don't need and allow to cool. I stand the cup in a cold water bath to promote rapid cooling. Once the temperature is 20°C, I pitch the yeast, swirl it around and add to the wort.

 

[Ghillie]

I just took the 65C water out the hot tap last time. Let cool to 30C and added the yeast. I'm not a believer in rehydrating dried yeast though. That was my second and last time re-hydrating yeast.

Boiling the kettle would be a better method though, sanitary practices, etc, etc. The reason I used water directly from the hot tap was just to see if I ran into any problems or not. Infections, off flavours, etc - and I did not. Nor did I detect any improvement or degradation of the beer.

Two things learned:

1. Sprinkling the yeast in is not detrimental to the beer.
2. Rehydrating yeast does not improve the beer. Not from a perceivable taste standpoint anyway.
3. Hot water direct from combi is fine.

 

[marshbrewer]

When I did used to hydrate yeasts, my technique was similar.

Boiling water into a clean, but not sanitised mug, the idea being that boiling water kills all. The water cools pretty quickly, but when at about 28/30° the yeast was hydrated in it as per packet instructions.

However, after time I came to the conclusion that simply sprinkling the dry yeast into the foam on top of the wort gave me the same results, so that's what I do now.

 

[ryderkellan]

Thanks everyone

 

[Mavroz]

I hydrate yeast in a glass beaker using boiling water cooled down with bottled water to around 20 to 25 degrees.

I add the yeast and put on the stir plate for 10 minutes or so then just add to the FV.

Works for me.

 

[Keruso]

I find it depends on the yeast manufacturer, I always boil a kettle and sanitize a glass jug, then pour in about 300ml water add 1/2 teaspoon dextrose and let it cool to 25c. Sprinkle on the dry yeast, leave for 15mins, then stir to make the “cream”. Cover with clingfilm and put in a dark place. With fermentis yeast it will be frothing up to the top of the jar within 1 hour so you know it’s going to start fermentation quickly, same with lallemand/danstar. However with mangrove jacks yeast it takes a lot longer, quite a few hours in my experience.

 

[Norfolk79]

When I did used to hydrate yeasts, my technique was similar.

Boiling water into a clean, but not sanitised mug, the idea being that boiling water kills all. The water cools pretty quickly, but when at about 28/30° the yeast was hydrated in it as per packet instructions.

However, after time I came to the conclusion that simply sprinkling the dry yeast into the foam on top of the wort gave me the same results, so that's what I do now.

Same here. And now Fermentis are now saying there’s no need to rehydrate yeast prior to pitching now too.

 

[dad_of_jon]

mj say 30-35C for their non lager yeasts. There is less lag if you re-hydrate. If you're happy with sprinkling the yeast of top why rehydrate? - I do higher gravity brews and only use a single packet so i'll continue to rehydrate. it doesn't add to the brew day length.

 

[Brew_DD2]

I always rehydrate warm about 35c after reading an article about it. No sugar should be required unless you're concerned that the yeast is old and no longer viable.