Why is it advised to rehydrate dry yeast with distilled water and not with mineral-ri

[Talgrath]

You should just use tap water. Danstar's official response to a question about distilled water:

http://www.danstaryeast.com/articles/dry-yeast-rehydration-conditions

You want the water sterile, so you boil it, but you do not want it to be distilled. Distilled water is water with no minerals in it, sterile water is sterilized water. Distilled water will actually cause yeast cells to burst and die because it will suck minerals out of the cells via reverse osmosis (side note: this is the same reason you do not want to drink distilled water). Boil tap water, cool it down to 105 F or lower and then add the dry yeast.

 

[Homercidal]

I should have canned some rehydration water last night when I had the canner out...

 

[PlexVector]

Not overly dramatic. Here is a video i took today of a yeast culture resuspended into distilled water

It looked like it just puked!

 

[Gavin C]

Not overly dramatic. Here is a video i took today of a yeast culture resuspended into distilled water

That's really cool.

Is this what we are seeing?

• Single yeast cell
  
• Exposed to distlled water
  
• Cell lysis and the cytoplasm being extruded ito the media.

All the instructions I've ever read from the manufacturers specify sterile water or wort and some clearly advise against use of distilled water for the reasons this video illustrates.
Danstar's response to this question.

 

[Finlandbrews]

You should just use tap water. Danstar's official response to a question about distilled water:

http://www.danstaryeast.com/articles/dry-yeast-rehydration-conditions

You want the water sterile, so you boil it, but you do not want it to be distilled. Distilled water is water with no minerals in it, sterile water is sterilized water. Distilled water will actually cause yeast cells to burst and die because it will suck minerals out of the cells via reverse osmosis (side note: this is the same reason you do not want to drink distilled water). Boil tap water, cool it down to 105 F or lower and then add the dry yeast.

Thanks for the reply talgrath! Now if we consider that the water is sterile by boiling it, would that tap water be better than bottled water? If we treat water for mashing, couldn't we treat it too for rehydrating dry yeast? Why I ask these is because :

1) yeast needs oxygen and boiling removes oxygen from the water

2) boiling doesn't remove chloramines and other amines compounds, are they affecting yeast

3) what if some mineral ranges dramatically change during boiling too

4) what about the best pH for yeast as tap water is usually above pH 8

 

[Finlandbrews]

You should just use tap water. Danstar's official response to a question about distilled water:

http://www.danstaryeast.com/articles/dry-yeast-rehydration-conditions

You want the water sterile, so you boil it, but you do not want it to be distilled. Distilled water is water with no minerals in it, sterile water is sterilized water. Distilled water will actually cause yeast cells to burst and die because it will suck minerals out of the cells via reverse osmosis (side note: this is the same reason you do not want to drink distilled water). Boil tap water, cool it down to 105 F or lower and then add the dry yeast.

Thanks for the reply talgrath! Now if we consider that the water is sterile by boiling it, would that tap water be better than bottled water? If we treat water for mashing, couldn't we treat it too for rehydrating dry yeast? Why I ask these is because :

1) yeast needs oxygen and boiling removes oxygen from the water

2) boiling doesn't remove chloramines and other amines compounds, are they affecting yeast

3) what if some mineral ranges dramatically change during boiling too

4) what about the best pH for yeast as tap water is usually above pH 8

 

[Talgrath]

Would it be better than bottled water? I'm not entirely sure, but it does work just fine.

1. The oxygen should be present in the wort if you are properly oxygenating your wort (and you are, right?), remember we're not fermenting the water.

2. I haven't noticed any negative effects.

3. I'd say they probably do...but again I haven't noticed any differenes.

4. What tap water are you drinking? Mine sits around 7.4.

Overall, remember that when we soak the yeast there's no fermentation activity, we're just rehydrating it before adding it to the wort. 15 minutes, even in a slightly less than ideal condition, is probably just fine as long as it isn't outright killing yeast (like distilled water would do).

 

[slym2none]

I imagine you can boil & cool most any non-distilled or RO water & it will be fine. I have used water from the tap, filtered water from my fridge, & the spring water I brew with, and never had any problems. My tap water tastes & smells like a swimming pool, but boiling it drives off chlorine/chloramines, so no worries there. (Note - this is why I use Kroger-brand spring water.)

 

[Ozarks Mountain Brewery]

I remember how my mother when baking fresh bread would take the dry yeast add it to warm water with a teaspoon of sugar just to see if the yeast was good, I'm pretty sure this is how re-hydration got started, as I remember it was just tap water or even well water and in all cases it worked, you just let it set until you see a small layer of foam on top....I think people are getting carried away with the details too much...as Nike said years ago which i just love this saying ...."just do it"

 

[1977Brewer]

I imagine you can boil & cool most any non-distilled or RO water & it will be fine. I have used water from the tap, filtered water from my fridge, & the spring water I brew with, and never had any problems. My tap water tastes & smells like a swimming pool, but boiling it drives off chlorine/chloramines, so no worries there. (Note - this is why I use Kroger-brand spring water.)

Try a batch of your tap water treated with campden. You most likely won't regret it, and save $$ per batch along the way.

 

[day_trippr]

That is so cool!

Cheers! (Poor li'l yeast...never had a chance to bud... )

 

[slym2none]

Try a batch of your tap water treated with campden. You most likely won't regret it, and save $$ per batch along the way.

Maybe if/when I start brewing again, I will try this.

 

[birchape]

That's really cool.

Is this what we are seeing?

• Single yeast cell
  
• Exposed to distlled water
  
• Cell lysis and the cytoplasm being extruded ito the media.

Yes this is a single yeast cell. This was after 10 minutes in distilled water. It is labeled with a fluorescent membrane marker that should normally just be visualised as a nice ring around the outside of the cell, the pressure had already damaged it giving the 'patchy' appearance. In longer videos the cytoplasm and cell contents keep being extruded for another couple of minutes before the whole cell breaks apart.

 

[joshesmusica]

I remember how my mother when baking fresh bread would take the dry yeast add it to warm water with a teaspoon of sugar just to see if the yeast was good, I'm pretty sure this is how re-hydration got started, as I remember it was just tap water or even well water and in all cases it worked, you just let it set until you see a small layer of foam on top....I think people are getting carried away with the details too much...as Mike said years ago which i just love this saying ...."just do it"

are you talking about The Mike, as in "I wanna be like Mike"-Mike? or did you mean Nike?

I tend to agree with you a bit on this. And I think it's the one thing that the non-re-hydrators cling onto with dear life: "But there's just as much of a chance to screw up the rehydration for the newbie. So instead of rehydrating, one might as well just pitch two packets dry."

I think as long as you're using pretty warm water (I usually don't go over 10F of my pitching temps, just so that way I don't have to mess with trying to cool it down. But then again, I usually pitch a little warm, and the ferment chamber easily brings it the rest of the way), letting the yeast kind of "soak into" the liquid, then give it a few stirs to make sure that most of the clumps are gone, then I think you're doing better than just dry pitching. I just use the thermometer-in-the-tap-water method, wait until it's about 25-27C, then gather the 110ml, and pour the yeast on top. Wait about 15 minutes or so, then stir it around really well. I'm usually doing the stirring part while I'm chilling down the wort, so I'll stop stirring the wort for a couple of seconds to give the yeast a stir. I'll keep doing that until the wort is at temps. I suppose more scientific testing could be done, but I tend to think that this is going to be better than dry-pitching. Maybe the guy with that awesome gif can do experiments for us with different rehydration temps?

 

[ncbrewer]

2) boiling doesn't remove chloramines and other amines compounds, are they affecting yeast

Whether chloramines affect the yeast or not, I don't want them in my wort to produce chlorophenols in the beer. I'm now using spring water, but when it's gone, I plan to use some of my campden-treated tap water. My tap water actually has chlorine, which shouldn't be a problem since I boil the water, but I would rather use campden-treated water just to be sure - the water department could decide to start using chloramines at any time.

 

[Gavin C]

Yes this is a single yeast cell. This was after 10 minutes in distilled water. It is labeled with a fluorescent membrane marker that should normally just be visualised as a nice ring around the outside of the cell, the pressure had already damaged it giving the 'patchy' appearance. In longer videos the cytoplasm and cell contents keep being extruded for another couple of minutes before the whole cell breaks apart.

Thanks for the clarification on the immunofluorescence. Beautiful imagery. Thanks again for posting it and explaining it in such detail. This is front page stuff. I would respectfully and humbly encourage you to share it this way. I'm sure this is not an isolated video you have. Really, a marvelous illustration of yeast abuse

 

[orangehero]

Sean Terrill found that rehydrating dry yeast in water (with some mineral content, not distilled) was better for yeast viability than wort...

http://seanterrill.com/2011/04/01/dry-yeast-viability/

You're correct, I suppose that would be the same as just pitching into the wort. Not sure what I was thinking about.

 

[Dan]

Honestly, if it's one of the big name dried yeast of today the rehydration comes from the water in the wort. Same reason the big guys purposely make dry yeast that needs no starter or wort o2 boost to get them going

Just saying. (Does anybody still use that phrase[emoji3])

 

[joshesmusica]

Honestly, if it's one of the big name dried yeast of today the rehydration comes from the water in the wort. Same reason the big guys purposely make dry yeast that needs no starter or wort o2 boost to get them going

Just saying. (Does anybody still use that phrase[emoji3])

No they don't... Well, my dad does, but he's typically using phrases like that 5-10 years after they've expired.

Water in the wort is not the same as typical tap water when it comes to rehydration. This has pretty much been proven, yet the dry-pitchers continue to propagate this idea. Will your beer ferment out if you pitch dry, sure it's likely. Will it be the best beer it could've been? Probably not. But that's not the point. The point is that approximately half of the cells that you pitch dry won't be able to handle the osmotic shock, and will spill its guts into your beer. But even that is not the point of the thread. As I stated before.

It's ok to come in arguing whether or not to rehydrate in threads asking that question, but the OP did not ask IF he should rehydrate, but rather HOW he should do so WHEN he does.