Dry Yeast Questions???

Im going to be brewing a full grain wheat ale. Im going to use Safale US-05. My first question is do I have to rehydrate the yeast or just pitch it dry. I know you could do both, but not sure what way is better. It seems people on here do both. If I do need to rehydrate how much water do I use for a packet of yeast? Also Im using BeerSmith to help me along the way. I know I need 42.8 billion yeast cells. I was wondering how to tell how many are in a packet? Basically do I need 1 or 2 packets? Want to make sure Im covering all the bases and this was the final one I had questions about. Thanks in advance to anyone who responds and helps.

Dave

Recently I counted a package of US-05 and there were 150 billion viable cells. I have found that the number of viable cells is dependant on how you re hydrate. I would recommend that after aerating your wort in an ale pail, sprinkle the yeast across the surface and seal it up and let it do its thing. You don't want to mix the yeast into the wort or water when hydrating.

Here are the results:
http://woodlandbrew.blogspot.com/2013/01/how-many-cells-are-in-package.html
(note that the package of US-05 in this post was not hydrated correctly)

More extensive details coming February 9th.

Also, how big is the batch? 40 billion cells isn't many.

To hydrate or not is one of those questions that get's asked all the time, and there's a ton of opinions on both sides of the argument, and ultimately you'll just have to decide for yourself. Because there really is no right or agreed upon way.

Here's one of the hundreds of discussions on the topic

WoodlandBrew said:

I counted a package of US-05 recently and there were 150 billion. I have found that the number of viable cells is dependant on how you re hydrate. i would recommend that after aerating your wort akin an ale pail sprinkle the yeast across the surface and seal it up and let it do its thing.
Here are the results:
http://woodlandbrew.blogspot.com/2013/01/how-many-cells-are-in-package.html

More extensive details coming February 9th.

Click to expand...

I like reading your stuff woodland many thanks for your research.

So you dont think rehydrating at the temp recommended and then pitching once that temp has come down to within 10 deg of the wort is necessary?? That is how i usually pitch dry yeast and it works great and fast.

RIC0 said:

I like reading your stuff woodland many thanks for your research.

So you dont think rehydrating at the temp recommended and then pitching once that temp has come down to within 10 deg of the wort is necessary?? That is how i usually pitch dry yeast and it works great and fast.

Click to expand...

What you are doing sounds like a great way to do it. It is very kind to the yeast for a number of reasons. It's certainly good, but I don't know if I would say nessisary.

WoodlandBrew said:

Recently I counted a package of US-05 and there were 150 billion viable cells. I have found that the number of viable cells is dependant on how you re hydrate. I would recommend that after aerating your wort in an ale pail, sprinkle the yeast across the surface and seal it up and let it do its thing. You don't want to mix the yeast into the wort or water when hydrating.

Here are the results:
http://woodlandbrew.blogspot.com/2013/01/how-many-cells-are-in-package.html
(note that the package of US-05 in this post was not hydrated correctly)

More extensive details coming February 9th.

Also, how big is the batch? 40 billion cells isn't many.

Click to expand...

Its a 5 gallon batch. Not sure why its so little, but that is what BeerSmith is telling me. This is the recipe Im using: http://www.brew365.com/beer_three_floyds_gumballhead.php

Is it possible to put in too much yeast, or will the extra just die off? Would it be wise to put in 2 packets just to be safe?

You should be close to 200 billion needed. IMO, 1 packet of US05 should be sufficient - sprinkled or rehydrated (I prefer rehydrated according to package instructions, but that's just me).

I have ALWAYS just sprinkled the dry yeast on top. However, this last batch, i decided to re-hydrate it for kicks, and "to me" the fermentation seemed to kick off a little faster. Could be my imagination though

stpug said:

You should be close to 200 billion needed. IMO, 1 packet of US05 should be sufficient - sprinkled or rehydrated (I prefer rehydrated according to package instructions, but that's just me).

Click to expand...

How much water do you use when you rehydrate 1 packet?

BrewIt said:

Is it possible to put in too much yeast, or will the extra just die off? Would it be wise to put in 2 packets just to be safe?

Click to expand...

You can have too much yeast, but either one or two packs should work fine. Wyeast has some good information about the effects of over pitching. After fermenting this beer you will have about 3 trillion yeast cells. So whether you pitch 150 billion or 300 billion it's not much of a difference.

I also noticed that the recipe is for 6 gallons. Assuming you don't scale the recipe the cell count for that grist is about 200 billion. 5 gallons of 1.062 takes the same amount of yeast as 6 gallons of 1.052. It's really a function of the amount of sugar. If you do scale it down to 5 gallons of 1.052 then it's more like 175. So if you do scale it down, 1 package would be closer.

All I did to make it easy on myself I am using 5lbs of wheat malt instead of 6lbs. Thats the only thing I did different. The OG should be 1.046 according to BeerSmith.

BrewIt said:

How much water do you use when you rehydrate 1 packet?

Click to expand...

I follow package instructions. In this case it would be:

-10x the package weight in water (11g package means 110g water)
-Water should be sterile (bottled spring water), otherwise boiled for a minute or two and cooled. In a cereal bowl would be good.
-Water should be 75-85F (80F is good)
-Sprinkle yeast evenly in 80F water in cereal bowl and cover (aluminum foil or plate)
-Let sit 15-30 minutes
-After sitting period, stir periodically for 30 minutes (every 5 minutes or so)
-Pour creamy mixture into wort (60-65F wort would be good)
-I like to give the fermenter a swirl after adding yeast

I've pitched dry yeast on several batches and had no weird affects but plan to rehydrate every time moving forward. If anything it seems to start faster.

Now Wyeast smack packs I'm not a big fan of,,,,, Yet.

Thanks everyone for all the help!