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

[Finlandbrews]

I was just wondering what is the idea with dehydrating dry yeast with distilled water. Wouldn't it be better for yeast to have water with mineral ranges (zinc, calcium, magnesium,...) that will feed their health?

Beside water temperature and volume, what mineral compounds, pH, and other stuff in the water are important to avoid when dehydrating dry yeast?

 

[Yooper]

I was just wondering what is the idea with dehydrating dry yeast with distilled water. Wouldn't it be better for yeast to have water with mineral ranges (zinc, calcium, magnesium,...) that will feed their health?

Beside water temperature and volume, what mineral compounds, pH, and other stuff in the water are important to avoid when dehydrating dry yeast?

I think you're talking about rehydrating dried yeast? If so, you want to make sure that the water is the right temperature and without much in it (due to osmotic pressure changes) to rehydrate the yeast.

 

[joshesmusica]

Like Yooper said, I'm sure you meant to say rehydrating. Also, it's because when the yeast is dried at the manufacturer, they've already provided all of the nutrients that the cells need to build up their cell walls again after dehydration. So you want the water with nothing in it, because as the cells are being rehydrated, their won't be able to pick and choose what enters through their cell walls. Everything just rushes in. That's also why it's sometimes advised to not pitch directly into the wort. If they get inundated with all of that all at once, it can lead to osmotic shock, which at best would stress them out, and at worst will kill them off.

 

[day_trippr]

I was just wondering what is the idea with dehydrating dry yeast with distilled water.[...]

fwiw, I don't know where your reference to "distilled water" came from, but here's a direct cut'n'paste from a Fermentis spec sheet:

"Re-hydrate the dry yeast into yeast cream in a stirred vessel prior to pitching. Sprinkle the dry yeast in 10 times its own weight of sterile water or wort at 27C ± 3C (80F ± 6F)."

Nothing about "distilled".

Best as I can recall from what I've read, distilled water is pretty much a no-no when farming yeast...

Cheers!

 

[flars]

Danstar, in their "Articles", is very specific about not using distilled or RO water to rehydrate yeast.

 

[kh54s10]

IDK, I have always just used tap water. I boiled and cooled the first time. Then I just started adjusting the hot and cold taps to get the proper temperature....

But then again I read an article locally that said my town has the best water in the area and far better than some nearby towns.

 

[stpug]

Best as I can recall from what I've read, distilled water is pretty much a no-no when farming yeast...

I also have it in my brain that distilled for rehydrating is bad, but can't remember why. Perhaps something about lack of any mineral content.

 

[Yooper]

fwiw, I don't know where your reference to "distilled water" came from, but here's a direct cut'n'paste from a Fermentis spec sheet:

"Re-hydrate the dry yeast into yeast cream in a stirred vessel prior to pitching. Sprinkle the dry yeast in 10 times its own weight of sterile water or wort at 27C ± 3C (80F ± 6F)."

Nothing about "distilled".

Best as I can recall from what I've read, distilled water is pretty much a no-no when farming yeast...

Cheers!

"Sterile" water is generally considered "distilled" water. It's perfect for using in rehydrating yeast.

 

[olotti]

I've just always used tap water boiled and cooled to about 90-100deg then drop the yeast in and go from there. After oxygenating wort with my O2 wand usually fermentation in less than 4-8 hours.

 

[day_trippr]

"Sterile" water is generally considered "distilled" water. It's perfect for using in rehydrating yeast.

No, "distilled" and "sterile" are not the same.

Boiling water does not remove the mineral content.
Distillation does exactly that.

And I'm pretty sure there's a passage in Yeast that explains why not to use distilled water with yeast...

Cheers!

[edit] Actually, you can just Google that stuff.
As well, one should not consider a gallon jug of distilled water purchased at the supermarket as "sterile".
Mineral-free, yes, but not "sterile"...

 

[MaddBaggins]

I always took fermentis instructions to mean "boiled". I always use filtered boiled water, cooled to rehydrate temp.

 

[orangehero]

Don't use distilled water. Ideally you want to use sterile wort, but boiled tap water should be adequate.

[edit] Actually, you can just Google that stuff.
As well, one should not consider a gallon jug of distilled water purchased at the supermarket as "sterile".
Mineral-free, yes, but not "sterile"...

Packaged water is usually UV disinfected. It's safe to treat the unopened gallon jugs of distilled water as sterile.

 

[bob1852]

Don't use distilled water. Ideally you want to use sterile wort, but boiled tap water should be adequate.

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/

 

[Kharnynb]

actually, rehydrating, you want some mineral content in the water to prevent the yeast from overhydrating and bursting.
Yeast has already got some salts/minerals inside the cellwall, osmosis will equalise the water content inside and outside the cell. too much water can lead to burst cell-walls.

 

[AkTom]

Being the slacker I am... I just use warm well water. It works for me.

 

[joshesmusica]

I stand corrected:

Most filtered tap water works well for rehydration. Ideally, the mineral content should range from 250 to 500 parts per million hardness.

From the book, "Yeast:..."

 

[brew703]

For a new brewer, it's difficult to determine which method is correct since there is always different answers.
I have used spring or filtered water to re-hydrate yeast and never had an issue.

 

[Psylocide]

I stick my thermometer under the tap, wait until the temp gets to where it needs to be, then fill my measuring cup and rehydrate.

 

[Homercidal]

I'm sure I read that distilled water is not the preferred water due to not having minerals the cells might need to complete their rehydration.

But it will work, and should work much better than rehydrating in wort, where the cells cannot regulate what come in or out yet and they can let stuff through their walls that will kill them, leading to an approximate 50% kill rate.

I've used distilled, spring water, tap water and all have worked fine. But that's anecdotal evidence. I'm guessing it was the book "Yeast" that suggested spring or tap water.

All sterile of course.

 

[joshesmusica]

I'm sure I read that distilled water is not the preferred water due to not having minerals the cells might need to complete their rehydration.

But it will work, and should work much better than rehydrating in wort, where the cells cannot regulate what come in or out yet and they can let stuff through their walls that will kill them, leading to an approximate 50% kill rate.

I've used distilled, spring water, tap water and all have worked fine. But that's anecdotal evidence. I'm guessing it was the book "Yeast" that suggested spring or tap water.

All sterile of course.

Yeah I quoted the section of the book only a few posts up.

 

[Homercidal]

Yeah I quoted the section of the book only a few posts up.

May be that's where I read it, but I'm sure I had heard it mentioned somewhere else as well, before I owned that book. Might have been a TBN podcast or somewhere.

Just went back and read my last post. I meant to say I read it somewhere besides the Yeast book...

 

[Dolomieu]

^ that is funny. When they had the ad campaign about "being better than Cleveland water" or something to that effect, the Cleveland folks analyzed it and found high arsenic levels.

Anyway, one would think this is simply based on osmonic pressure. Ion free water is not good for organisms, period. If you put a fathead minnow in 100% RO or Distilled water, it dies. That death is due to the osmonic pressure placed on the fry. No one would call it toxic, bit it isn't good for life.

The only thing that may be different with dehydrated yeast would be that there may be minerals/ions left behind with the yeast. So its plausible that you could use Distilled or RO water and that there would be enough material to give you a the profile that was left behind from the dehydrating process. I don't use dry yeast so I won't be experimenting but I would think a safe SOP would include using water which contained minerals.

 

[PlexVector]

^ that is funny. When they had the ad campaign about "being better than Cleveland water" or something to that effect, the Cleveland folks analyzed it and found high arsenic levels.

Anyway, one would think this is simply based on osmonic pressure. Ion free water is not good for organisms, period. If you put a fathead minnow in 100% RO or Distilled water, it dies. That death is due to the osmonic pressure placed on the fry. No one would call it toxic, bit it isn't good for life.

The only thing that may be different with dehydrated yeast would be that there may be minerals/ions left behind with the yeast. So its plausible that you could use Distilled or RO water and that there would be enough material to give you a the profile that was left behind from the dehydrating process. I don't use dry yeast so I won't be experimenting but I would think a safe SOP would include using water which contained minerals.

The way I understand it with dist or RO water the cell could absorb water too quickly and damage it.

EDIT: okay maybe not the perfect picture to explain it...

 

[Dolomieu]

The way I understand it with dist or RO water the cell could absorb water too quickly and damage it.

EDIT: okay maybe not the perfect picture to explain it...

Right, so I think of it as water rushing in an exploding the cells. Overly dramatic and it wouldn't look that way in a microscooe, but keeps the idea in my head. It is still a result of the osmonic pressure placed on the yeast in the environment that you are placing them in, at least as far as I can tell.

When we use to culture fathead minnows, occasionally when we would try someone new they would change the fry bucket over with RO instead of moderately hard water. This would result in almost complete death of the fry in the bucket and any that managed to survive would be tossed due to the compromise in their health.

 

[Ozarks Mountain Brewery]

I don't rehydrate my dry yeast at all, never have, I do pour wort then yeast then more wort so it is submerged then oxidate after the yeast is mixed, always works for me

 

[ncbrewer]

Dr. Clayton Cone of Lallemand (see this link: https://koehlerbeer.wordpress.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/) states "The water should be tap water with the normal amount of hardness present. The hardness is essential for good recovery. 250 -500 ppm hardness is ideal. This means that deionized or distilled water should not be used. Ideally, the warm rehydration water should contain about 0.5 – 1.0% yeast extract."

The part about - 0.5 - 1.0% yeast extract lost me.

 

[flars]

This is the article I referred to: http://www.danstaryeast.com/articles/dry-yeast-rehydration-conditions

 

[flars]

I don't rehydrate my dry yeast at all, never have, I do pour wort then yeast then more wort so it is submerged then oxidate after the yeast is mixed, always works for me

Try rehydrating your yeast, then compare notes on the finished beer for any differences.

 

[bob1852]

Try rehydrating your yeast, then compare notes on the finished beer for any differences.

My results have been similar to those reporter here...

http://brulosophy.com/2014/09/15/sprinkled-vs-rehydrated-dry-yeast-exbeeriment-results/

 

[birchape]

Right, so I think of it as water rushing in an exploding the cells. Overly dramatic and it wouldn't look that way in a microscooe, but keeps the idea in my head. It is still a result of the osmonic pressure placed on the yeast in the environment that you are placing them in, at least as far as I can tell.

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