Rehydrating yeast

[martyr]

I've read a few posts about rehydrating the yeast before you add it. I've only made one batch, it was a Russian imperial stout and I just spread it over the top. Is it better to rehydrate it first?

 

[k1ngl1ves]

Some people do, and some don't. People will always argue this topic.


Generally speaking, I feel it's probably better to hydrate beforehand for yeast health.

Although, I have just sprinkled it in before and called it a night...

 

[martyr]

Cool thanks for the help

 

[aprichman]

I've read a few posts about rehydrating the yeast before you add it. I've only made one batch, it was a Russian imperial stout and I just spread it over the top. Is it better to rehydrate it first?

Hello fellow Oregonian!

Look at the directions on the yeast. Most directions recommend rehydration but there are a few that have been optimized for pitching directly on to the wort.

I usually use Fermentis/Safale products, the directions recommend rehydrating but then also say you can directly pitch on top of the wort

The first few beers I made I pitched directly on to the wort, I figured rehydrating would just add another step that I could possibly mess up. My beers turned out fine when I did this.

A few brews later I gained some confidence and decided to rehydrate the yeast - after all the package DID recommend it. I noticed that my yeast seemed much, much happier when I did this - fermentation was much more vigorous and I noticed I was hitting my expected FGs more consistently.

Now I always rehydrate my yeast. I usually brew smaller batches (2.5 gallons) so rehydrating would probably be even more beneficial if you are using a single packet for larger batches.

Cheers

 

[flugelizor]

According to Chris White (White yeast labs), when you DON'T properly rehydrate you kill 50% of the yeast.

 

[unionrdr]

That's about right. the dry yeast's cell walls are weaker when hydrated in the fresh wort. Rehydrating in water of 80-90F for 30 minutes makes for stronger cell walls in the yeast, so more of them survive pitching to cut lag or reproductive phase.

 

[Clonefan94]

I won't specifically say with facts that my beer is better when I rehydrate dry yeast, but my perception of my beer is better. I say this because I don't have any strong factual evidence, but it does seem cleaner and the fermentation more vigorous when rehydrated.

I usually heat my strike water on my stove, while doing this, I also put a couple hundred milliliter a in my flask and boil that down to around 100 at the same time I'm heating my strike water. Then I put a piece of sanitized foil over the top and let it cool. This then times out about right to be able to add the dry yeast to it when the water is around 80 degrees or so and its ready to pitch when I need it. Once you work it into your brew day, it's pretty easy to do.


Sent from my iPhone using Home Brew

 

[unionrdr]

I put a couple hundred mL of spring water in my flask & nuke it to about 90F, checking it with my All-Temp laser thermometer. It's pretty handy for checking temps in the flask or fermenter right through the side. Then sprinkle in the yeast to sit covered with sanitized plastic for 15 minutes per manufacturer's directions. Then sanitize a skewer to stir it in to sit another 15 minutes or so. Pitching it at high krausen also seems to make it get through the reproductive (lag) phases a bit faster. I've had some dry yeasts like S-04 start visibly fermenting in about 3 hours this way. Finished once & clearing in 10 days.

 

[flugelizor]

I put a couple hundred Ml of spring water in my flask & nuke it to about 90F, checking it with my All-Temp laser thermometer. It's pretty handy for checking temps in the flask or fermenter right through the side. Then sprinkle in the yeast to sit covered with sanitized plastic for 15 minutes per manufacturer's directions. Then sanitize a skewer to stir it in to sit another 15 minutes or so. Pitching it at high krausen also seems to make it get through the reproductive (lag) phases a bit faster. I've had some dry yeasts like S-04 start visibly fermenting in about 3 hours this way. Finished once & clearing in 10 days.

"high krausen" means it is fermenting with sugar.
You don't want to make a malt starter with dry yeast.
Just rehydrate with water per the directions on the package.

 

[helibrewer]

Rehydrate! Use 25mL of water per gram of yeast (not RO or DI) at 104F. After 10 minutes, add wort in the same quantity as your rehydration water and wait 20 minutes, you should see yeast activity at this point. Keep adding wort (using the same amount as your first addition) until the rehydrated yeast temp and your wort temp are within 10F of each other, then pitch.

For optimum fermentation consider using about .2 ppm of zinc in your fermenter.

 

[unionrdr]

"high krausen" means it is fermenting with sugar.
You don't want to make a malt starter with dry yeast.
Just rehydrate with water per the directions on the package.

Krausen refers to the yeast foam on top & doesn't necessarily denote the use of malts. Even rehydrating dry yeast will produce a krausen when properly done in plain water. In my case, spring water.

 

[ncbrewer]

Rehydrate! Use 25mL of water per gram of yeast (not RO or DI) at 104F. After 10 minutes, add wort in the same quantity as your rehydration water and wait 20 minutes, you should see yeast activity at this point. Keep adding wort (using the same amount as your first addition) until the rehydrated yeast temp and your wort temp are within 10F of each other, then pitch.

For optimum fermentation consider using about .2 ppm of zinc in your fermenter.

It's interesting that you mention adding the same quantity of wort as rehydration water. Danstar's TDS instructs to add a wort quantity of 10%. It would take forever to reach your target temperature using their instructions.

 

[Gavin C]

I'm a firm believer in reading the manual.

My thinking is that the companies creating dry yeast have expended some considerable efforts to deliver an optimal product and supply very clear guidelines for their use.

It requires minimal effort on my part to follow the instructions to get the best from their product. If the veracity of the science behind rehydration is to be taken at face value; and I see no reason to doubt it, rehydration is likely to result in a more optimal fermentation.

Isn't that desirable?

 

[BlueHouseBrewhaus]

Just to really confuse things, a rep from Fermentis told my LHBS guy (who also owns/operates a local brewery) that you can do it either way and that he personally pitches dry. That threw me for a loop because I had always rehydrated. Since hearing this, I have brewed several batches each way with no discernible differences in FG or flavor. I did not, however, do a split batch with any of them. All that being said, I have gone back to rehydrating because 1) it really isn't that hard, 2) it doesn't hurt, and 3) it may help.

 

[unionrdr]

I'm a firm believer in reading the manual.

My thinking is that the companies creating dry yeast have expended some considerable efforts to deliver an optimal product and supply very clear guidelines for their use.

It requires minimal effort on my part to follow the instructions to get the best from their product. If the veracity of the science behind rehydration is to be taken at face value; and I see no reason to doubt it, rehydration is likely to result in a more optimal fermentation.

Isn't that desirable?

It seems to cut lag time till visible fermentation & finishes faster or at least more completely in my opinion.

Just to really confuse things, a rep from Fermentis told my LHBS guy (who also owns/operates a local brewery) that you can do it either way and that he personally pitches dry. That threw me for a loop because I had always rehydrated. Since hearing this, I have brewed several batches each way with no discernible differences in FG or flavor. I did not, however, do a split batch with any of them. All that being said, I have gone back to rehydrating because 1) it really isn't that hard, 2) it doesn't hurt, and 3) it may help.

I've found that it definitely cuts lag time & makes for a steadier fermentation.

 

[watermelon83]

Just to really confuse things, a rep from Fermentis told my LHBS guy (who also owns/operates a local brewery) that you can do it either way and that he personally pitches dry. That threw me for a loop because I had always rehydrated. Since hearing this, I have brewed several batches each way with no discernible differences in FG or flavor. I did not, however, do a split batch with any of them. All that being said, I have gone back to rehydrating because 1) it really isn't that hard, 2) it doesn't hurt, and 3) it may help.

Another fella did.

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

 

[MInoobbrewer]

I usually rehydrate mine but this last brew I didn't and while it did ferment vigorously at first it seemed to poop out fast.

 

[martyr]

Awesome thanks guys for all the info. I'm gunna brew another batch on Tuesday and I am gunna try the rehydrated yeast and see if it helps. I appreciate all your input.

 

[Pkrd]

Just to really confuse things, a rep from Fermentis told my LHBS guy (who also owns/operates a local brewery) that you can do it either way and that he personally pitches dry.

Maybe he gets yeast for free so pitches twice as much dry. I would.

 

[cobrem]

Part of the equation is your OG. If you have a high gravity wort, you need more yeast to handle the work without stressing the yeast and creating off-flavors or other problems. If you have a relatively low gravity wort, direct/dry pitch maybe OK - 50% loss might still leave you with enough troops for a good fermentation. Check out the pitching calculator at mrmalty.com before you brew to make sure you are in the ballpark.

 

[martyr]

Hmm I never thought of the wort calling for a dry pitch.
I'm making a rip, here's the recipe http://www.homebrewersassociation.org/homebrew-recipe/split-open-and-melt/
Maybe it should be a dry pitch

 

[unionrdr]

I prefer to rehydrate dry yeast, regardless of style. The style of beer usually doesn't matter as to dry or rehydrated yeast pitch. Rehydrating & pitching within 10 degrees of current wort temp will ensure a healthy pitch. Pitching dry into the wort can weaken cell walls & cause up to 50% cell death.

 

[cobrem]

For the RIP recipe you posted above, OG is high (1.100 or so). I'd definitely rehydrate, and would probably use two packets of yeast to make sure there is an appropriate amount of yeast.

 

[IslandLizard]

Just to really confuse things, a rep from Fermentis told my LHBS guy (who also owns/operates a local brewery) that you can do it either way and that he personally pitches dry. That threw me for a loop because I had always rehydrated. Since hearing this, I have brewed several batches each way with no discernible differences in FG or flavor. I did not, however, do a split batch with any of them. All that being said, I have gone back to rehydrating because 1) it really isn't that hard, 2) it doesn't hurt, and 3) it may help.

A rep is not necessarily a research scientist or a brewer, and his/her expertise should lie in an entirely different domain (sales) to be a good rep.

I would take Chris White's advice as more authoritative when it comes to yeast. Although I'm sure he likes to see his sales increase too.

Most manufacturers of dry yeast have instructions on how to rehydrate their product. There are small but notable differences among those methods. Attempering the rehydrated yeast slurry is also a good method, that may increase viability or faster growth. Pitching dry does not acclimate the yeast by any means and may therefore be an inferior method.

 

[martyr]

That's funny that you mentioned to use two packs of yeast I thought the same but that's what it called for so I stuck with it. I'm not to sure on wether not that would make for a yeasty taste in the final product.
I'll read up on it, and agin thanks for the input the more I know the better thanks guys.

 

[CKing]

Once you work the process into your brew day and figure out the timing it's no bother at all.
I'll boil the required amount of water around the same time my wort is placed on the burner. The water is covered and left to cool at room temperature.
By the time I am ready to chill the wort, the rehydrated yeast water is typically at the right temperature range so I'll add the dry yeast and rehydrate while the wort chills. Then it's ready to pitch at just the right time.

Yes it's an extra step, but a very easy one to work into your process.