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Author Topic: WLP002 VS Fermentis Safale S04  (Read 46615 times)

Offline nateo

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Re: WLP002 VS Fermentis Safale S04
« Reply #15 on: August 24, 2012, 07:33:10 pm »
Just as a practical matter, too, if you rehydrate the yeast between 105-109*F you'll get close to 90% viability for dry yeast. For every -10*F drop in rehydration temp, you lose 10% viability. So for best results, don't just sprinkle onto wort. (The instructions from Fermentis differ, but I'd ignore those). If you just sprinkle on wort, you'll kill about half the dry yeast. Since there is about 230b cells in an 11.5g packet, losing half isn't disastrous, but may be deleterious to your beer.
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Offline tygo

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Re: WLP002 VS Fermentis Safale S04
« Reply #16 on: August 24, 2012, 08:00:29 pm »
Just as a practical matter, too, if you rehydrate the yeast between 105-109*F you'll get close to 90% viability for dry yeast. For every -10*F drop in rehydration temp, you lose 10% viability. So for best results, don't just sprinkle onto wort. (The instructions from Fermentis differ, but I'd ignore those). If you just sprinkle on wort, you'll kill about half the dry yeast. Since there is about 230b cells in an 11.5g packet, losing half isn't disastrous, but may be deleterious to your beer.

So you're saying that viability of the yeast is related to the temperature of the water you rehydrate in?  So if I rehydrate in 98F water I'm killing 10% more cells than if I do it in 108F degree water?  I'm not sure I understand that.  Where are you getting that from?

I always thought that the argument for rehydration was more related to the sugars from the wort rushing into the cells as opposed to the temperature.
« Last Edit: August 24, 2012, 08:09:31 pm by tygo »
Clint
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Offline nateo

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Re: WLP002 VS Fermentis Safale S04
« Reply #17 on: August 24, 2012, 09:16:18 pm »
So you're saying that viability of the yeast is related to the temperature of the water you rehydrate in?  So if I rehydrate in 98F water I'm killing 10% more cells than if I do it in 108F degree water?  I'm not sure I understand that.  Where are you getting that from?

I always thought that the argument for rehydration was more related to the sugars from the wort rushing into the cells as opposed to the temperature.

That slope figure (10* per 10%) is my own interpretation. It might not be perfectly linear. Here's what I'm basing that on: http://koehlerbeer.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/

IIRC Denny was the one who told me about that Q&A in the first place, though maybe not that exact link. My temp range from memory wasn't exactly correct. I was thinking of the 105-109* range given by lallemand for their wine yeasts.

If you try rehydrating the yeast at different temps, you'll notice the yeast becoming creamy and active much quicker at 105* than 85*, so there must be something going on there.
« Last Edit: August 24, 2012, 09:20:34 pm by nateo »
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Offline denny

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Re: WLP002 VS Fermentis Safale S04
« Reply #18 on: August 25, 2012, 09:45:37 am »
You should really do a split batch and compare them for yourself. I'm a big fan of Denny, but I don't agree with him on everything. Taste is subjective, and you might find S-04 to be the best yeast ever, for your taste. I happen to like S-04 a lot, especially for making cider. I made a special bitter with S-04 I thought was good, but nothing fantastic. More of my friends loved that beer than any of the other beers I'd made before.

Deciding for yourself is what homebrewing is all about.  Obviously, we don't all have the same tastes and it's your own that count.
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Offline tonyp

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Re: WLP002 VS Fermentis Safale S04
« Reply #19 on: August 25, 2012, 12:02:02 pm »
I know this doesn't answer the OP's original question but its good info on comparing White Labs vs Wyeast:

Yeast Strain Comparison Chart (White Labs, Wyeast)

Thanks!
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Offline nateo

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Re: WLP002 VS Fermentis Safale S04
« Reply #20 on: August 25, 2012, 12:10:37 pm »
For info on dry yeast strains, I like to look at the probrewer.com forums. Dry yeast isn't that popular among homebrewers, but a lot of pros use it since it's so cheap. I think the wholesale on 500g bricks is like $50. I have no idea how much an equivalent amount from a yeast lab would cost, but I think it's a lot more than that.
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Offline tygo

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Re: WLP002 VS Fermentis Safale S04
« Reply #21 on: August 25, 2012, 12:52:54 pm »
That slope figure (10* per 10%) is my own interpretation. It might not be perfectly linear. Here's what I'm basing that on: http://koehlerbeer.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/

Interesting read.  Thanks.
Clint
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Offline nateo

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Re: WLP002 VS Fermentis Safale S04
« Reply #22 on: August 25, 2012, 02:46:19 pm »
After I read that, I started rehydrating my yeast at 105* +/- a few degrees. Before that, I was rehydrating in the 60-70*F range. I also use Go-Ferm now. Go-Ferm is a yeast nutrient that doesn't have inorganic nitrogen (DAP). DAP is really harmful to yeast during rehydration, so don't use any yeast nutrient that contains DAP. As far as I can tell, Go-Ferm is basically Fermaid K without the DAP.

I noticed a difference right away when I switched my procedure. When properly rehydrated, the yeast gets creamy, sticky, and bubbly, just like kraeusen. If you don't do it right, the yeast wants to drop to the bottom of the container like sludge (I guess that's all the dead yeast).
In der Kürze liegt die Würze.