Rehydrating & pitching dry yeast

[GuingesRock]

^ Interesting.

I caved and threw in some US-05 ...bugger it!

[CorneliusAlphonse]

Ahh too bad - some yeast can have lag time in the 24-48 hour range. I don't worry about it til then.

[GasMD30]

I have yet to rehydrate my dry yeast, although I do over pitch so I must compensate for it. Hasn't steered me wrong yet!

[jeffsmith]

Ahh too bad - some yeast can have lag time in the 24-48 hour range. I don't worry about it til then.

Same here. I don't start getting nervous until 36hrs+.

[dean2k]

Ahh too bad - some yeast can have lag time in the 24-48 hour range. I don't worry about it til then.

Same here. I don't start getting nervous until 36hrs+.

The interweb seems to be in agreement that the Mangrove Jack M44 is a notorious slow starter.

[GuingesRock]

I was going by Trevor's experience with it.

http://www.brewnosers.org/forums/viewto ... m44#p98311" onclick="window.open(this.href);return false;

[jacinthebox]

ive done both rehydrate and dry sprinkle. ..both work...but my lag time is cut substantially when I rehydrate.

[jtmwhyte]

I was going by Trevor's experience with it.

http://www.brewnosers.org/forums/viewto ... m44#p98311" onclick="window.open(this.href);return false;

Remember that mine was in a 4% Cream Ale and the packets are 10 grams, not 11.5

Mine took off like a rocket and I used the yeast cake for a 7% Stout

[Jayme]

Just catching up reading some of my old (but new to me) issues of BYO, and an Ask Mr. Wizard (Ashton Lewis - whom I believe was one of Nash's instructors) said the following, which made me think of this old thread/debate (https://byo.com/stories/issue/item/3107 ... -mr-wizard):

It has been a while since I have used dried yeast and did a little reading before answering this question. All good references I found on this topic did not leave any doubt in my mind about what is best for the yeast cell, and that is to rehydrate dried yeast with water prior to pitching into wort (or must for any winemakers out there in the audience).

The basic reason behind this practice is that cell membranes serve a variety of important functions for the cell and these functions all require membranes that are fluid. And when dried yeast cells are hydrated in a liquid other than water, like brewer's wort, there is a short timeframe when compounds that ordinarily do not pass across the cell wall do indeed cross the cell wall. This leads to a reduction in cell viability in comparison to yeast that has been hydrated in warm water. While the optimum rehydration temperature seems to be strain-dependent, the range cited is usually 95–105 °F (35–41 °C). As the rehydration temperature decreases, viability following rehydration also decreases; rehydrating in water warmer than 105 °F (41 °C) also decreases viability.

The likely cause for this on-going debate is that rehydrating in wort does not result in total failure. So the argument follows that rehydrating in wort works, therefore arguments about rehydration in water and improved viability are simply textbook. In practice, commercial breweries place yeast viability and vitality towards the top of yeast topics that clearly influence beer quality. I believe in the "put your money where your mouth is" gauge. Based on what is said and done vis-à-vis equipment investments in pursuit of yeast
viability and vitality, the logical con-clusion is that this is indeed a worthwhile pursuit.

My recommendation to new homebrewers is to add different techniques as the basics are mastered and when new and more advanced brewing methods are an avenue to either better beer or something of practical interest. I certainly would not suggest jumping from dried yeast to liquid yeast simply because there are two arguments about yeast hydration. You can certainly brew excellent tasting beer using dried yeast and the basic science suggests that hydrating in warm water prior to pitching is the best way to handle this type of yeast.

[chalmers]

Good find, Jayme, thanks for posting it.

[LeafMan66_67]

ive done both rehydrate and dry sprinkle. ..both work...but my lag time is cut substantially when I rehydrate.

I tried a couple batches of US -05 side by side, one sprinkled and one rehydrated. Lag time was less by at least six hours with the rehydrated as well. I now rehydrate all the time.

[GuingesRock]

ive done both rehydrate and dry sprinkle. ..both work...but my lag time is cut substantially when I rehydrate.

I tried a couple batches of US -05 side by side, one sprinkled and one rehydrated. Lag time was less by at least six hours with the rehydrated as well. I now rehydrated all the time.

I found this today on the subject. http://www.brewnosers.org/forums/viewto ... nkle#p6554" onclick="window.open(this.href);return false;

I suspect the pros don't rehydrate, least not the ones I know.

I've always been told that dry yeast should first be rehydrated with water before introducing it to wort. Dehydrated yeast first needs water to properly re-establish cell wall permeability before taking in food from malt sugars. Viability is supposedly higher in water hydrated dry yeast compared to wort hydrated yeast. I've not tested this myself though.

John

I haven't always been told this but i have read it a lot Seriously though, I don't think it makes much difference in this scenario. it may be more important for 'proper' pitch rates, repitching etc. I've re-hydrated in water many times, in wort many times, and no re-hydration at all many times, in my real world experience it doesn't make a whole lot of difference but I certainly haven't done any scientific experiments or much reading on it. It seems a bit bizarre that a packet didn't get 1.5L going in a hurry, what was the gravity of this starter? It's also important to note that I was wrong once.

But! That's a useful observation you made Derek.

[NASH]

When I use dried yeast it's thoroughly mixed in with O2 during knockout from kettle to fermenter. If I pour it on top afterward lag time is doubled, at least

[RubberToe]

Greg, when and how do you add the dry yeast like that? I'm assuming you don't throw it into the kettle unless you cool it while recirculating.

[NASH]

That's right.

I add it to the fermenter through the prv port (on top of the tank) after I have a couple hl of wort in the cone. For the remaining ~25 minutes of cooling in it's being thoroughly mixed in via flow turbulence and O2 injection.

[GuingesRock]

One of the functions of rehydrating on a small scale system, may be that it facilitates mixing of the yeast in the wort as per Greg's discussion. It's a possible explanation for the reported reduced lag time with rehydrating. I'm not disagreeing with the standard explanation though. I whirlpool cool down to fermentation temperature. That makes me wonder if I should keep the whirlpool going when I pitch, rather than just sprinkling on the surface.