how much yeast?

[rats_eyes]

I am planning my second and third AG brews, after doing a handful of kits over the last 9 months or so. This forum has provided a huge portion of the info that I've needed to get going! I've got some conflicting info about yeast quantity, I wonder if any of you have experience that might help me decide what to do.

The recipe is an IPA ("red dwarf ale", in beersmith recipes section), I'll be brewing to 25l, starting gravity is an estimated 1.048. I'll be using US-05 dry yeast. The recipe suggests just one pack, but beersmith reckons that only using two will do the trick.

I don't want to over pitch, though I'm not really sure how likely this would be to mess with my beer. I have some youngs yeast nutrient. I'm thinking that I'l pitch the one 11g pack (rehydrated) and use the nutrient to boost it up a bit. Does this sound like a good idea?

 

[Rivvo]

It sounds ok to me, as us05 is a clean fermenting yeast with high attenuation I believe?
However for more expertise it may be worth posting this at jims beer kit or the craft brewing forum, unfortunately a lot of the experienced brewers appear to have left this site, don't know why?

 

[Duxuk]

If you rehydrate at the correct temperature you will give the cells the best chance, so 1 pack willprobably suffice. If you just sprinkled youmay well need twice the yeast, since half can die when sprinkled. I always rehydrate Gervin GV12 at 35-37C , but this may not be correct for your yeast. Do you have the rehydration temp. information?

 

[rats_eyes]

The yeast pack doesn't mention rehydration at all, but fermentation temp should be 15-22c. I'll go for that range for rehydration

 

[serum]

The yeast pack doesn't mention rehydration at all, but fermentation temp should be 15-22c. I'll go for that range for rehydration

Rehydrating is a good shout. I always do that with dried yeast and it seems to work well. I'm doing my second next weekend as well, will let you know how it goes.

 

[chrisstuarthall]

I tend to use Fermentis yeasts, mainly S04, will now use S05 for IPAs. They do not recommend re-hydration for their yeasts if you read the info sheets you can download off their web site.

They say to sprinkle on top, leave for 30 minutes and then stir in.

I just sprinkle on top and then seal up tight, I try to keep air contact to a minimum.

I haven't had any trouble doing this thus far and the fermentation is up and running vigorously within 24 hrs at maximum.

 

[Duxuk]

You should rehydrate US-05 at blood temp., so 35-37C. DO NOT REHYDRATE IT AT THE RECOMMENDED FERMENTATION TEMPERATURE.
The 2 are different things. Boil some water and sterilise your thermometer. Leave this to cool naturally to 35-37C, add the yeast and stir with a sterilised spoon, then leave this mixture to drop to the temp. of your wort, then add. This will give maximum yeast cell survival. Add the sachet to water at 15C or so and you could kill half of them.:ugeek:

 

[chrisstuarthall]

Apologies to all. Just reread their leaflet....Duxuk is spot on with his info.