Rehydrating vs not rehydrating

[Ibrew2little]

Rehydrating yeast vs non rehydrating. I've done the rehydration and fermentation took as long as 48 hours to start. Last batch I just tossed the yeast into my wort after transferred to my fermenter and I was fermenting in <12 hours. What do you normally do?


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[hunter_le five]

I always rehydrate dry yeast.

If you don't, you are likely killing a lot of your yeast before they even have a chance to get started.

There are probably other factors that cause the lag time differential you experienced, so jumping to the conclusion that it was the rehydration is probably incorrect.

 

[Ibrew2little]

Perfect. And my apologies I just looked down and seen a whole other thread on same topic


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[CaptainAl]

The last 6-8 batches I have done have been direct pitch w/o re-hydrating. I was making starters for some of the "bigger" beers but honestly I haven't had a problem. I did 2 batches this weekend (1x1.056 and the other was a 1.074) and they have been chugging away ever since. Blow-off tube and tank are full of residue and the krauzen looks great. Activity started in less than 12 hours for me as well.

To be honest I have a barleywine and smoked porter I am going to be doing and will probably make starters for those.....just because I did the last time and they turned out great!!

 

[Ibrew2little]

Ok. So sounds like your higher gravity beers your better making starters. Have you guys used liquid yeast? What is your experience with those


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[Qhrumphf]

I always rehydrate dry yeast.

If you don't, you are likely killing a lot of your yeast before they even have a chance to get started.

There are probably other factors that cause the lag time differential you experienced, so jumping to the conclusion that it was the rehydration is probably incorrect.

This.

If yeast are exposed to sugars while still in their more fragile dry state, they can't regulate what they're taking in, they start rupturing, and you get about 50% cell death, and all of a sudden you're underpitching. It'll still make beer, but you've lot the chance to make the best beer.

First things first, don't get into the mindset of "faster is better" when it comes to anything about fermentation, including lag time. While healthy fermentation usually does start and proceed faster than an unhealthy fermentation, if you take your generic American Ale strain, and pitch it into 95 degree wort and hold it at 95 degrees, fermentation is going to take off like a rocket, but that doesn't make it good. Point is, HEALTHY fermentation is more important than FAST fermentation (or short lag, or anything else applicable).

Presumably the batch that took off faster when you just tossed the dry yeast straight in was warmer (could be good or bad depending on the beer), but also could have had more oxygen introduced prior to pitching (typically a good thing). Either one could lead to a shorter lag time.

Of course if they're different recipes or different yeasts, then there's a bunch of other factors to consider and you really can't isolate enough variables to compare the two.

 

[CaptainAl]

Ok. So sounds like your higher gravity beers your better making starters. Have you guys used liquid yeast? What is your experience with those


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Sure I have used a bunch of the liquid yeasts all w/good results. I have made starters when they were closer to the use by date or when the smack-pack didn't swell up as much as prior ones.

 

[hunter_le five]

Have you guys used liquid yeast? What is your experience with those

Liquid yeast is great, so long as it's 1) reasonably fresh, 2) has been stored properly, and 3) you make a starter for it.

Overall, there are a LOT more strains available in liquid form than dry, so I tend to use liquid yeast more often than not.

 

[BreezyBrew]

Rehydrating yeast vs non rehydrating. I've done the rehydration and fermentation took as long as 48 hours to start. Last batch I just tossed the yeast into my wort after transferred to my fermenter and I was fermenting in <12 hours. What do you normally do?


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I think the lag time is directly related to temperature, not necessarily healthy yeast. When rehydrating, the yeast are very warm, then thrown into a much cooler environment. This shocks them some and it takes longer to adjust rather than going from frig temp to pitch temp.

 

[fartinmartin]

I pitched the dry yeast direct for years, BUT , now wouldnt dream of doing it, so many vibs from the forum implied that we should rehydrate, so I did , and wish that I had taken notice earlier.
Proving that we kill half the yeast we pitch dry I cant prove , but after rehydrating, knowing that I have a jug full of live and active yeast is another control factor that is all buttoned up. The more control factors that we are in control of must be the way to go. Some control factors are constrained by equipment, this simple little one isnt.

 

[kh54s10]

There is will do and the best practices.

Sprinkling dry yeast - will do. It will ferment.

Pitching liquid yeast without a starter - will do. It will ferment.

But pitching the proper amount of healthy yeast will make your beer better. That means rehydrating dry yeast and making starters with liquid yeast.

 

[boydster]

I always rehydrate dry yeast. Here is some good reading about why:

http://seanterrill.com/2011/04/01/dry-yeast-viability/
http://seanterrill.com/2011/07/29/dr...lity-take-two/
http://seanterrill.com/2010/05/09/ye...-rate-results/
http://koehlerbeer.com/2008/06/07/re...-clayton-cone/
http://home.comcast.net/~mzapx1/FAQ/Rehydrate.pdf
http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.2011.tb00482.x/pdf

 

[MKBoitnott]

You can search this topic in here, read books, listen to podcasts, ask breweries, and your LHBS, and the large majority will tell you rehydrating is better. Its easy to do and people have actually researched it. I would trust that information. It absolutely can't hurt.

I'm also surprised no one mentioned the "don't make a starter for dry yeast" advice yet. This is also a topic that most experts would also agree on.

Another caveat that I'll add is to eventually move to liquid yeast. It's a little more cost prohibitive and makes the process more challenging (making starters is a MUST), but you get waaaaaaaaaaaay more variety and a better end product.


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[Qhrumphf]

Ok. So sounds like your higher gravity beers your better making starters. Have you guys used liquid yeast? What is your experience with those


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I rarely use dry yeast, almost always use liquid. Generally recommended to make starters with liquid yeast, since they contain far fewer cells than the average 11.5g sachet of dry yeast. Otherwise the average 5 gallon batch of 1.050-1.060 OG ale should really get two packs (or a sufficient starter), with more for higher gravities, and double the amount for lagers.

Many folks (including myself) use the Mr. Malty calculator: http://www.mrmalty.com/calc/calc.html

There's another calculator that's just as good (with different strengths and weaknesses: http://www.yeastcalculator.com/

And an article from Mr. Malty about making starters: http://www.mrmalty.com/starter_faq.php

(Mr. Malty aka Jamil Zainasheff literally cowrote the book on yeast with Chris White of White Labs).

What I do is make session beer as my "starter". I'll brew 5 gallons of something around 1.030-1.035 OG, and then just pitch directly out of the smack pack or vial assuming my yeast is fresh. Generally the yeast I get from my LHBS is already a week or two to a month old (after transit time plus store turnaround and what not) depending on the popularity and turnaround of the strain, which is about as old as I'd let it go and still pitch straight out of the pack/vial. If it's older than that (whether bought that way or if I don't use it right away) I'll make a very small starter, and then proceed. And then that starter beer will provide me with plenty of yeast to brew whatever I want (assuming it uses the same yeast strain of course). I'll usually rinse out enough slurry from the yeast cake to pitch into two separate batches, one big, and another small, and then repeat again from the second small beer, until I've taken one vial or smack pack for maybe 5 generations.

Although if you don't know what you're doing regarding harvesting yeast, I wouldn't recommend doing it that way until you've got more experience. Your cleaning/sanitizing will need to be top notch, and when repitching yeast if you don't pay attention you can actually end up overpitching (especially if you do what some folks do and just dump one beer onto the yeast cake of another- I'll do that if I'm brewing a 1.115 Barleywine or a Doppelbock or something like that, but otherwise it's a bad plan.)

 

[Qhrumphf]

I'm also surprised no one mentioned the "don't make a starter for dry yeast" advice yet. This is also a topic that most experts would also agree on.

My understanding on this one is that dry yeast manufacturers stock their yeast with lots of nutrient reserves (glycogen and what not), and that making a starter then depletes them. And it can actually result in a slower start as a result. It doesn't actually HURT anything, but it's got drawbacks.

However, that also requires time plus some extra DME, and it ends up being cheaper and faster to just pitch a second pack of dry yeast if the first pack isn't enough.

So point, I guess, is that you CAN make a starter for dry yeast, but there's really not a good reason to do it unless you literally only have one pack of yeast for a beer needing two (and with 11.5g dry yeast and 5 gallon batches, it takes a pretty high gravity ale, or a lager, to need two anyway), and you simply cannot get more. Desert island or zombie apocalypse sort of scenario.

 

[mabrungard]

There is more than sufficient research study evidence that shows that yeast viability is improved by rehydrating in water. The evidence is that tap water or RO water is suitable. Interestingly, it turns out that adding magnesium to the rehydration water significantly improves yeast viability. The linked journal article presents that info.

http://www.academia.edu/18740265/Vitality_enhancement_of_the_rehydrated_active_dry_wine_yeast

The 5 to 10 millimole magnesium concentration shown in the article equates to about 1 to 2 grams of Epsom Salt per quart of water. The results of this article agree with the research that I presented in articles on calcium and magnesium requirements for yeast that were printed in Zymurgy and The New Brewer. Yeast prefer magnesium over calcium for their health.