Rehydrating dried yeast

[ziggy13]

So I have a fairly unique situation when it comes to rehydrating my yeast. My city water is chlorinated, so we have a charcoal filter that does a great job of filtering that out. The only problem is my only filtered water source is not heated, so it comes out at water temperature the ground water is. When I rehydrate my yeast I know you're supposed to use around 80 degree water farenheit according to the package. Do you think it's an issue to rehydrate the yeast at a lower temperature, or should I take the time to actually heat it up to the suggested temperature?

I have also not been sterilizing the water, and have yet to have any problems. Seems my water coming out of the filter is pretty sterile as is. I've been considering getting another burner in my setup so I can easily sterilize the water, and then let it cool to 80 degrees, and then rehydrate, but it seems like a lot of extra work if I'm getting pretty good results as I'm doing things now.

Anyone have any opinions on this?

 

[kh54s10]

My city water must have some chlorine or chloramine in it. I use a Britta filter and use my microwave for about 5 seconds to get the filtered tap water to 90 degrees. If you are worried about the water, buy some spring water.

 

[jeremy0209]

I currently use a Coleman camp burner and boil my water in a flask for 15 minutes. Then, I chill that to 86-90F and rehydrate my yeast. I, personally, wouldn't use water that is lower than the suggested temp for rehydrating. Yeast are super sensitive to temp and you want the first water they see, after being given the Han Solo treatment, to be pretty warm.

 

[goswell]

I had question regarding rehydrating dry yeast so I emailed the company (Fermentis in this case). Here is their response

I have spoken with our R&D Director in the past about the necessity of rehydrating and we decided there really isn’t any need to. If you direct pitch the dry yeast into your fermenter, you will lose ~3% viability and the fermentation will start after ~1 hour (given that the yeast will be rehydrating for the first hour.

I have used our yeast many times in home brewing as well as commercial brewing and have had no issues with direct pitching the dry yeast into my fermenters. I would suggest that you pitch the dry yeast directly into the fermenter

I took their advice and pitched the yeast without rehydrating. I'm telling you, the beer was amazing. I know internet folklore says you lose 50% viability but for one batch, just pitch it right from the packet. Rehydrating probably maximizes your yeast viability but the process of rehydrating, then getting that slurry to proper pitching temps can cause you to end up with less healthly yeast than if you just opened the packet and pitched it.

Just try it sometime.

 

[ziggy13]

I was pitching directly into the fermenter for a while, and then with one batch of Nut Brown it came out smelling super alcoholic, almost like it was a Russian Imperial or something. First couple sips sort of burned as well. It was only 6% ABV though. The only thing I could figure out was that the yeast was stressed out. Fermentation temperatures were good to go the whole way through. So I started rehydrating in water that comes right out of my charcoal filter at room temperature and haven't had the problem since.

I would love to just pitch the dried yeast into the wort, but I need to figure out what the problem was with that Nut Brown I made and why it tasted so alcoholic...

 

[Psylocide]

I rehydrate with tap water... I figure 4 oz of untreated water into 5.5 gal really can't harm your beer.

I do boil it in the micro first, and let it cool to ~85 or so.

Haven't had any issues.

 

[wailingguitar]

I have used Ferments yeast, both home and at the commercial scale, without rehydration since about '98 or '99. Many, if not most, commercial breweries that use dry yeast don't bother with hydration. Pitch the yeast into your fermenter then dump the wort on top of it, you'll be fine.

 

[ziggy13]

Anyone have any idea why S-04 may have created extremely alcoholic smelling and tasting beer in a typical Nut Brown recipe when pitched at 70 degrees F and fermented around 64-68 for a week?

 

[Indian_villager]

I brita filter the water and boil the hell out of it in he microwave in just the glass of a mason jar for 2 minutes just as I am heating up my boil. I then take out the jar and cap it with a sanitized cap. The water cools off to a useful rage just about the time I have 10 mins left in the boil.

 

[WoodlandBrew]

Anyone have any idea why S-04 may have created extremely alcoholic smelling and tasting beer in a typical Nut Brown recipe when pitched at 70 degrees F and fermented around 64-68 for a week?

It's hard to know for sure, especially with a sample size of one, and so many variables. It sounds like you are describing fusel alcohols which are normally associated with warm temperatures, especially at the beginning of fermentation. 70°F is on the hot side for S-04 according to the data sheet. If it wasn't the temperature, I would guess that the taste may have been due to some kind of contamination.

 

[BigFloyd]

I know internet folklore says you lose 50% viability but for one batch, just pitch it right from the packet.

Not sure you got the idea that's "internet folklore". Those are findings given in an interview by Dr. Clayton Cone (who was working for Lallemand) based on microscopic cell counts for dry yeast rehydrated in tap water at various temperatures as well as pitched directly into wort. Wort is a somewhat unfriendly environment for the dry cells that have yet to reconstitute their cell walls.

Rehydrating probably maximizes your yeast viability but the process of rehydrating, then getting that slurry to proper pitching temps can cause you to end up with less healthly yeast than if you just opened the packet and pitched it.

I'd agree with this. Unless a brewer knows how to properly rehydrate yeast and then attemperate the slurry to get it close to the wort temp before pitching, they're probably better off sprinkling it dry into the wort. The good news is that an 11g packet of dry yeast usually contains such an abundance of cells as to compensate for our often imperfect attempts at using it.

 

[WoodlandBrew]

Agreed. While you can get by with sprinkling the packet of yeast on the wort and make fine beer, it has been shown that viability is lower when yeast is rehydrated in wort.

Here is one paper on the subject:
Bolata, Irina C., Maria Turtoib, and Michael C. Walsha. "Influence of yeast drying process on different lager brewing strains viability." Journal of Agroalimentary Processes and Technologies 15.3 (2009): 370-377.

(Viability and rehydration is a fairly complicated topic. For example, this paper shows that while viability is lower when hydrating with wort, after 24 hours most of the cells that stained as "dead" now stain as "alive")

And another:
http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.2011.tb00482.x/pdf
While the current study has focused on the rehydration of yeast under laboratory conditions, these results may indicate that directly pitching ADY into wort (particularly cooler, lager type worts) could potentially result in viability loss and negatively influence fermentation performance.

I've also seen that the temperature of the water has a large impact on viability.

 

[kombat]

I know internet folklore says you lose 50% viability

Also the book "Yeast," co-written by Chris White, President and founder of White Labs yeast.

It's not "folklore" - it's science.

 

[PoppinCaps]

Well, the founder of a liquid yeast company dogging the viability of dry yeast competitors...

It may be true, but starting with even 110 billion viable cells will make a fine beer. Just did it last month. Science be damned.

I guess I'm saying my interpretation of this internet folklore is that they want you to think you can't make good beer directly pitching dry yeast. Don't believe it.

 

[ziggy13]

Thank you for all of the great information.

@BigFloyd, do you know where I could find more information from Dr. Cone?

 

[ziggy13]

I guess what I'm really trying to figure out is since I'm only able to currently rehydrate with room temperature water, is it worth my time to rehydrate like this or should I just pitch directly?

 

[kombat]

Why are you only able to rehydrate with room temperature water? Do you not have a hot water faucet? Or a stove? Or a microwave?

 

[BigFloyd]

Thank you for all of the great information.

@BigFloyd, do you know where I could find more information from Dr. Cone?

https://koehlerbeer.wordpress.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/