Dry yeast questions

Not sure whether this would be something you are interested in but, predominantly, conventional practices have you pitching dry yeast straight from the packet into your wort or rehydrating and then pitching.

Pitching dry, powdered, yeast into wort supposedly depletes the viability of the contents in the pack by somewhere from around 40 to 60%. Some kind of sugar shock damages the cell membranes as the yeast is rehydrating in the wort. However, dry yeast is packaged and ready to start propagation straight away, due to lipids providing plenty of oxygen, so the yeast can very often overcome, within reason, the loss in viability that occurs from this method.

Rehydration in sterile (in other words boiled then cooled) water, at the stated optimum temperature for the strain, yields the best potential viability for the yeast to be pitched into wort.

Most of the time you'll be informed here that making a starter with dry yeast is a no-no, as it defeats the purpose of the yeast. Pitching dry yeast powder into wort shocks and damages the yeast.

Another member on HBT (Tre9er) had an interesting view on the topic which I'm inclined to agree with;

After you rehydrate your dry yeast, add it to the wort, it starts propagating then, after lag is complete, goes to work converting the sugars. Lag is just the yeast going through its reproductive phase to build up sufficient viability.

So, how is that any different from pitching rehydrated yeast into a starter wort?? Actually, a starter wort is going to be, generally, lower gravity than a brew's wort, so even less stressful an environment for the yeasts first few hours. So, for example, only having one pack of dry yeast, mrmalty.com tells you that you need 1.75 packs to ferment your batch, rather than pitching two packs you can do a starter to increase cell count/viability like this.

Ogri said:

conventional practices have you pitching dry yeast straight from the packet into your wort or rehydrating and then pitching.

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It seems that most experienced brewers advocate rehydrating the yeast before pitching. Someone suggested adding a small amount of the cooled wort to the rehydrated yeast a couple minutes before pitching to give the yeast a little chance to acclimate themselves to the conditions in the wort. What do you think of that practice?

Ogri said:

only having one pack of dry yeast, mrmalty.com tells you that you need 1.75 packs to ferment your batch, rather than pitching two packs you can do a starter to increase cell count/viability like this.

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Palmer suggests that for most beers below 1.050 OG there are sufficient cells in a pack of dry yeast to do a good job of fermentation. Do you disagree with this?

here's an article I read:

Dr. Clayton Cone suggests the following:
Let me give you some facts regarding rehydration and you can decide for yourself where you want to Compromise.
Every strain of yeast has its own optimum rehydration temperature. All of them range between 95 F to 105F. Most of them closer to 105F. The dried yeast cell wall is fragile and it is the first few minutes (possibly seconds) of rehydration that the warm temperature is critical while it is reconstituting its cell wall structure. As you drop the initial temperature of the water from 95 to 85 or 75 or 65F the yeast leached out more and more of its insides damaging the each cell.
The yeast viability also drops proportionally. At 95 – 105 F, there is 100% recovery of the viable dry yeast. At 60F, there can be as much as 60% dead cells. 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.
For the initial few minutes (perhaps seconds) of rehydration, the yeast cell wall cannot differentiate what passes through the wall. Toxic materials like sprays, hops, SO2 and sugars in high levels, that the yeast normally can selectively keep from passing through its cell wall rush right in and seriously damage the cells. The moment that the cell wall is properly reconstituted, the yeast can then regulate what goes in and out of the cell. That is why we hesitate to recommend rehydration in wort or must. Very dilute wort seems to be OK.
How do many beer and wine makers have successful fermentations when they ignore all the above? I believe that it is just a numbers game. Each gram of Active Dry Yeast contains about 20 billion live yeast cells. If you slightly damage the cells, they have a remarkable ability to recover in the rich wort. If you kill 60% of the cell you still have 8 billion cells per gram that can go on to do the job at a slower rate.



More viable yeast means less off flavors and less stress.

fizgig said:

That is why we hesitate to recommend rehydration in wort or must. Very dilute wort seems to be OK.

More viable yeast means less off flavors and less stress.

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I'm glad to see that posted in this thread. Thank you. Eveyone working with dry yeast needs to be aware of just how vulnerable the little critters are during that first few minutes before we pitch them into the wort.

The article does seem to give a nod to the practice of adding a little wort to the rehydrated yeast just before pitching --- "Very dilute wort..." --- Do you agree with this practice?

Puddlethumper said:

It seems that most experienced brewers advocate rehydrating the yeast before pitching. Someone suggested adding a small amount of the cooled wort to the rehydrated yeast a couple minutes before pitching to give the yeast a little chance to acclimate themselves to the conditions in the wort. What do you think of that practice?

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I assumed that "adding a small amount of the cooled wort to the rehydrated yeast a couple minutes before pitching" was more to get the rehydrated yeast and wort to within a lesser temperature differential in a certain amount of time (ideally they should be within 10f of each other). I think I've read that you should be pitching rehydrated yeast by around 45 minutes from rehydration so as to get the optimum performance. I haven't tried adding wort to my rehydrated yeast as I've been lucky enough to get my wort and rehydrated yeast both down to about 62 to 68f by the time I want to pitch.

Certainly would seem to be a sound practice, though.

Puddlethumper said:

Palmer suggests that for most beers below 1.050 OG there are sufficient cells in a pack of dry yeast to do a good job of fermentation. Do you disagree with this?

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No, definitely don't disagree with that, if it's an 11.5g pack of yeast that's within or reasonably close to it's "use by date". In fact, I've never had any problems (particularly bad attenuation, non-carbonation, off flavours etc. etc.) using a single 11.5g pack of fermentis with any 5 gallon batch up to at least 1.065, and that includes in my first year of brewing before I even tried rehydrating my yeast.

Have also had good results from pitching a portion of a previous brew's yeast cake. Have yet to do proper rinsing of my yeasts.

Ogri said:

I assumed that "adding a small amount of the cooled wort to the rehydrated yeast a couple minutes before pitching" was more to get the rehydrated yeast and wort to within a lesser temperature differential in a certain amount of time ..

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I haven't been able to locate the article I read on the topic so I can't quote it chapter and verse. The gist of it, as I recall, was that by adding a small amount of cooled wort to the rehydrated yeast a few minutes before pitching gave the yeast some time to acclimate to the general chemistry of the wort. Getting the temperature close was a given.

Ogri said:

Have also had good results from pitching a portion of a previous brew's yeast cake. Have yet to do proper rinsing of my yeasts.

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One thing I really want to do is to try harvesting some yeast and saving it for another batch. Sort of "yeast ranching". I have a few more skills to develop before I try that , though.

Puddlethumper said:

Great idea! Did you pitch a full packet of yeast in each half?

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It was 10 gallons so each one was 5, so yes. Both were tasty, they were totally different. It would be cool to do the same thing with 2 similar yeasts for a more subtle comparison....

Demus said:

It was 10 gallons so each one was 5, so yes. Both were tasty, they were totally different. It would be cool to do the same thing with 2 similar yeasts for a more subtle comparison....

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Just out of curiosity, if you were to split a 5 gallon batch woud you pitch a full packet in each half, or would you split the yeast packet?

I'd probably use half a dry yeast pack properly rehydrated, or if liquid a full pack without a starter or a very small one...

At this point most of this has already been covered, but you seem receptive to any informed input, so here's mine:

05- I find this yeast imparts little to no character of it's own. I use this when I want the beers profile to come only from the malt and or hops. it is clean, and it adds nothing other than the conversion of sugars to ethanol. It ferments fairly, but not overly dry at typical ale fermentation temps.

04- I know this yeast is supposed to ferment dry also according to what I've read, but I find that at the temps that I like it at it stops fairly early, for example 1.015-1.020 for an average gravity beer. It has a unique flavor profile that I describe as slightly sweet and like cantaloupe. The colder you ferment it, the cleaner it gets, but I've held this yeast in the mid 50's and still have gotten a slight sweet fruit taste. Many people dislike this yeast, and I do prefer Nottingham for English ales, but I do have a few recipes that I use this in. I mostly use this for spiced beers in which I'd like a complex slightly sweet flavor profile. I tend to ferment this at between 55-60 degrees.

Nottingham-I use this yeast for any traditional English style. It gives a nice English fruit flavor profile without overpowering the rest of the ingredients. I find this yeast to be more forgiving than 04 when it comes to temperatures, though I still prefer to keep fermentation at or near 60 degrees. This yeast has less of a cantaloupe flavor than 04, and more of a delicate and mysterious fruity flavor. I've use this for English style ales, fruit beers, and ciders. This is one of the yeasts that I use most often.

Windsor- I've only used this yeast twice, and though I'm sure somebody out there has had success with it, it was certainly not me. I've tried to use this as an English ale yeast, but it has always finished with an ester profile akin to a saison yeast and such poor attenuation that the beer was almost undrinkably sweet. Unless you're feeling experimental, I would try to steer you away from this yeast.

34/70- In fewer words this would be the 05 of dry lager yeasts. I find this yeast to be a blank canvas when you stay within the lower end of the manufacturers recommended temperatures. I use this for bock's and I get rich malty bock's. I use it in pilsner's and they are crisp, clean, and have a beautiful hop profile. This is my lager yeast of choice when I want to play it safe; I always know exactly what I'm getting.

s-23- If 34/70 is us-05, than s-23 is Nottingham. If I'm brewing a lager and I want some participation from the yeast other than just lowering the gravity and raising my chances of getting a DUI, This is my go-to. The description from the manufacturer is a "fruity continental lager yeast" though I find it to be a little different than just fruity. It adds a flavor that, at least to me, lies just beneath the taste threshold. It feels like there is a spice similar to vanilla that is almost there, but not quite. I've used this yeast with great success in pilsners, and any style of helles, but it is an absolutely vital ingredient in the Pennsylvania Porter recipe that my friend and I came up with.

Belle Saison- I've only brewed with this yeast once thus far, but I will definitely be doing so again. I used it in a "spare parts beer": the second runnings from a scotch ale with wild hops, black and white pepper, and agave nectar. I fermented this at around 73-75 degrees, and it finished very quick and attenuated very well. In 5 days, this yeast brought the gravity from 1.042 down to 1.002. It was hard to tell how much was the yeast, and how much was the pepper, but for a saison yeast it was very spicy, and not that fruity.

I have never used s-189, but from what I've read it falls somewhere between 34/70 and s-23. I have been meaning to try this out, but I've not gotten around to ordering it.

As far as wheat beer yeast, I've only ever used wyeast 3069 and have been happy with it, though I really should and would like to try out the dry alternatives.

For extract brewing of high-gravity beers:

When I occasionally brew a high-gravity extract beer, I use dry wine yeast to chew away at some of the unfermentables in DME and LME. I have had good luck with Montrachet, and Premier Cuvee in extract barley-wines and Imperial Russian stouts.

Edit: I always rehydrate my dry yeast as per the instructions, and I use one packet per 5 gallons of 1.060 or less wort. If I'm brewing a split batch, I use half a packet for each batch that is under 5 gallons, be it 4 gallons or 1.

kaboom133 said:

At this point most of this has already been covered, but you seem receptive to any informed input, so here's mine:

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This, my friend, is exactly the kind of feedback I was looking for when I started this thread. Thank you for taking the time to write it. It will be printed and saved in my brewing file as a "go-to" reference as I learn more about brewing.

Thanks again!

Wow! Kaboom, thanks for the detailed notes! Good info that I will use as I move forward.
I'm cheap and prefer using either dry yeasts of recycling ones I like, so that is very helpful.

I'm glad the info helps. Keep in mind that those notes are just my experience with the yeast. Your setup may produce somewhat different results, and your taste buds might pick up things that mine missed. Use that as a guide, but experiment and taste each for yourself: a taste is worth 1000 words.

In case anyone is still following this thread, I have come across another dry yeast question/issue. I tried used T-58 for a wit and it seems to be really super sluggish. I started a thread under Ingredients/Yeast but have gotten very little response. If you've used this strain before I'd like to know more about your experience with it.