Rehydrate or Not ?

[devilssoninlaw]

Getting ready to start a BB Red Ale kit that came with Lallemand Nottingham yeast. The yeast packet calls for rehydrating while the instructions for the kit says "do not rehydrate yeast"!

Does it really matter if I do or don't? I've used this yeast before with good results after rehydrating. Just wondered why they say not to do so. Thanks!!!

 

[doogie]

A lot of beginner kits say that to (In my opinion) not intimidate the new brewer.
I always rehydrate my dry yeast.

 

[BrewnWKopperKat]

Ancidotal: I pitch Nottingham without rehydrating and the beer comes out fine.

Factual: dry yeast instructions vary with the yeast lab. Recent product information sheets for the Fermentis and Mangrove Jacks dry yeast I use indicate it's OK to pitch yeast without rehydrating.

If I were a kit maker: I would write the instructions to pitch it dry. This removes the opportunity for someone to kill the yeast when attempting to rehydrate.

If I were to start reusing dry yeast in future batches, I would investigate the idea that I want rehydrate the yeast and aeriate the wort to help get the yeast ready for the repitch.

 

[doogster]

I pitch US-05 without rehydrating with no issues.

 

[MaxStout]

When there is conflicting advice, go by what the packet says. I'll trust the manufacturer of the yeast over kit instructions written by some random dude.

 

[Smellyglove]

I'd rehydrate, unless the beer gets some flavor from un-rehydrated yeast.

This is an anecdote to hydrating/not hydrating yeast.

I haven't brewed this for maybe a year or two (time flies, who counts) But I did a beer for maybe eight batches pretty back to back with WB-06. I wanted it to be phenols. Every time I rehydrated the yeast, I got way less phenols. I grabbed a handful of the yeast from the same batch, so the batch of yeast was the same for every attempt. I even tasted the same difference in a friends beer which did my recipe, hydrated vs non hydrated yeast.

I mailed Fermentis about this, and they "didn't agree". It should taste the same, but, they never did brewing trials, just lab-trials, looking at numbers. The rep said he would try to replicate my experiences but he never go back to me, even after I asked after a few months. So I myself per now, wouldnt' trust even the manufacturer, but only my own prior experiences with a given yeast.

 

[devilssoninlaw]

Thanks gentlemen! I've seen this thread beat to death in the past and apparently there's no definite answer, the one piece of advice that really sticks with me is to follow the yeast packet instructions. They should know best about their product.

 

[Soulshine2]

What volume is the yeast packaged ? Some are 7 g , others like I get are 11g. I DO NOT rehydrate my dry yeast . It is a direct pitch after I've aerated my wort upon transfer .Normally most dry yeasts are cultured and packaged where rehydrating is not required ,and some say not beneficial either. YMMV. 7 g of dry yeast should give you enough yeast cells to pitch 5 gallons and under...11 g is more like a calculated over pitch in packaging ..300,000 cells if I read correctly.

 

[RM-MN]

I've read that up to 50% of the dry yeast can die if you direct pitch. I've also read that a pitch of yeast will double in about 90 minutes. To me that means that if I dry pitch it will delay the onset of fermentation by about 90 minutes, inconsequential when I expect the beer to be in the fermenter for 10 to 20 days.

 

[mongoose33]

I've read that up to 50% of the dry yeast can die if you direct pitch.

I've read that too.

I've also read that a pitch of yeast will double in about 90 minutes.

I've read that too, but I think it's unclear, and maybe together we can puzzle this out. I've read in the White/Zainesheff "Yeast" book that a 1-liter starter inoculated with 100 billion cells will end up with 152 billion cells.

I'm struggling with this. Apparently 48 billion cells have decided not to divide, and anyone who's done a starter knows it's not done in 90 minutes, or even 180 minutes.

I'm not arguing with you--I've read the same thing you have. But I've read other stuff too that contradicts it, and I can't resolve the issue (and I know one is dry and one is liquid, but still).

To me that means that if I dry pitch it will delay the onset of fermentation by about 90 minutes, inconsequential when I expect the beer to be in the fermenter for 10 to 20 days.

I think you're forgetting lag time. I don't think yeast, especially dry yeast, just pops in and starts reproducing.

At any rate, I've read enough lately to suggest you can get away with pitching dry yeast directly, and even if you start with 200 billion dry cells and half die, you still end up with 100 billion to start.

 

[RPh_Guy]

Who here likes experiments?

http://seanterrill.com/2011/04/01/dry-yeast-viability/

https://bkyeast.wordpress.com/2013/03/13/more-on-yeast-rehydration/

https://www.researchgate.net/public...rewing_Yeast_and_its_Effect_on_Cell_Viability

I seem to recall another experiment where viability was the same rehydrated vs sprinkled but I can't seem to find it, sorry.

And everyone's favorite...
http://brulosophy.com/2014/09/15/sprinkled-vs-rehydrated-dry-yeast-exbeeriment-results/

anyone who's done a starter knows it's not done in 90 minutes, or even 180 minutes.

How do I know when the yeast is done with the growth phase?

I don't think yeast, especially dry yeast, just pops in and starts reproducing.

Absolutely correct
Lag phase -> growth phase -> stationary phase.

Anecdotally, I've sprinkled an overpitch of dry yeast (5g/gal) and it was visually fermenting within 30 minutes.

 

[BrewnWKopperKat]

I seem to recall another experiment where viability was the same rehydrated vs sprinkled but I can't seem to find it, sorry.

Maybe What?! Dry Yeast Rehydrate vs Non-Hydrate Lab Results in Wort

I... up to 50% of the dry yeast can die if you direct pitch.

The Yeast book (2013), p 124, say that "failure to rehydrate dry yeast properly will result in the death of approximately half the cells".

 

[Gravity]

A lot of beginner kits say that to (In my opinion) not intimidate the new brewer.
I always rehydrate my dry yeast.

I do it all the time - do it.
Its a net gain with no negatives except having to prepare ahead of time and more time on your side.

 

[Soulshine2]

I've read that up to 50% of the dry yeast can die if you direct pitch. I've also read that a pitch of yeast will double in about 90 minutes. To me that means that if I dry pitch it will delay the onset of fermentation by about 90 minutes, inconsequential when I expect the beer to be in the fermenter for 10 to 20 days.

According to Ray Daniels- (Designing Great Beers ,Ch12, Yeast and Fermentation ,page 118 )
"Most of the foil packets of dry yeast sold for home brewing contain 7 grams of yeast ,and some contain as much as 14 grams. I counted a sample recently and found 20 billion cells per gram of dried yeast material. Thus , a 7-gram packet should deliver 140 billion yeast cells ,which is just about right for a 5 gallon batch "

I try to use the 11.5g packets myself .Thats 230 billion yeast cells... Plenty of yeast there , even if 50% die still leaves you with 115 billion cells. More than plenty for a 5 gallon batch. He states that 10-20 billion yeast cells ,even though a "reduced rate" is an achievable "home brew pitching rate" . Well, by those numbers, I have 10x that already, even at the 50% dead. If your rate of doubling is correct, They'll regrow back to full force in 90 minutes anyway ,right?

He goes on in a later paragraph that counting cells in the average sample of a Wyeast liquid ,after the package has expanded (a smack pack ,hes speaking of here) only has 2.5 billion cells and after several other packages were counted , he found as little as only 1 billion cells.

Also , if one were to try to make a starter from liquid or slant , the amount to be pitched would be almost 1.2 GALLONS to as much as 3 GALLONS to achieve the commercial pitching rate for just a 5 gallon batch. AND take up to a week to achieve those amounts.

Daniels- Pg 119."The richest source of yeast for pitching is the bottom of your fermenter. If you can arrange to brew every few weeks ,you can repitch the yeast from a prior batch and meet the commercial pitching rates with no problem"

For me- I don't brew the same beer consecutively , nor do I use the same yeast or I would surely use this method given that the yeast during its consecutive work schedules, don't change (evolve/morph). I'll keep the money needed to buy a starter ,stir-plate, flasks, etc and continue to pitch my 11.5 g dry yeast, lose 50% and still be done fermenting by the time a starter can be grown. STILL, I still save the yeast cake from my fermenter . As my brewing experience progresses, I may actually use one .
YMMV

 

[Northern_Brewer]

The Yeast book (2013), p 124, say that "failure to rehydrate dry yeast properly will result in the death of approximately half the cells".

That would be the yeast book written by Chris White, who has a direct financial interest in making dry yeast look bad?

I'd make two points : one, manufacturing improves with time, and most of the tests of modern dry yeast seem to indicate that survival rates of 80-90% are possible without rehydration now.

Two - even if it was 50% death rate for direct sprinkling, you have to compare that with the non-zero percentage of yeast that dies when you rehydrate, it's the difference between the two that matters and not the absolute number.

As well as requiring extra time and planning, any additional process gives another opportunity for infection. The less you mess about with your yeast, the better.

 

[BrewnWKopperKat]

The Yeast book (2013), p 124, say that "failure to rehydrate dry yeast properly will result in the death of approximately half the cells".

That would be the yeast book written by Chris White, who has a direct financial interest in making dry yeast look bad?

That's the book. I wanted a source for the "50% kill rate" so that people involved in this topic would have an approximate date for when the statement was made. When it comes to basic science, statements can be timeless. Fermentis changed their product information sheets, probably in 2018, to include the option for pitching it dry. And I've talked with a couple of pro craft brewers who are doing this with Fermentis yeast - it works well for them and I thought their beer tasted good.

I'd make two points : one, manufacturing improves with time, and most of the tests of modern dry yeast seem to indicate that survival rates of 80-90% are possible without rehydration now.

Two - even if it was 50% death rate for direct sprinkling, you have to compare that with the non-zero percentage of yeast that dies when you rehydrate, it's the difference between the two that matters and not the absolute number.

As well as requiring extra time and planning, any additional process gives another opportunity for infection. The less you mess about with your yeast, the better.

Agreed.

 

[eric19312]

5-11gram yeast packets are packaged specifically for homebrewers. There is limited surface area on the packet to provide instructions so the manufacturers go with short and simple instructions for use. However if you are curious they do also provide more detailed instructions on their websites.

https://fermentis.com/wp-content/uploads/2017/10/SafAle-US-05.pdf
- describes 45-60 min rehydration process in detail
- provides direct sprinkle method as alternative

http://www.lallemandbrewing.com/docs/products/bp/BEST-PRACTICES_REHYDRATION_DIGITAL.pdf
- rehydration is preferred and provides detailed techniques

https://cdn.shopify.com/s/files/1/0...68-8d16-673b5fb84f75.pdf?16489226078703376035
- Mangrove Jack's buries the information in the detailed instructions...see page 3

Muntons and Coopers stuck with the sprinkle instructions but they seem to be a different business model than fermentis ans lallemand...selling simple easy extract kits to homebrewers vs supplying yeast to commercial and homebrewers. I trust Fermentis and Lallemand a lot more when it comes to yeast and always rehydrate.

 

[Northern_Brewer]

That's the book. I wanted a source for the "50% kill rate" so that people involved in this topic would have an approximate date for when the statement was made. When it comes to basic science, statements can be timeless. Fermentis changed their product information sheets, probably in 2018, to include the option for pitching it dry.

I think your meant "undated" rather than "timeless". Some science is timeless, some dates very quickly - I think the original experiments on yeast viability that led to the 50% number were actually performed 10-15 years ago and manufacturing has moved on with things like the new coating that Fermentis are using for the Easy2Use products.

Don't quote me, but from memory it was more like October 2017 that they officially became neutral on rehydrating or not, but they waited until the E2U branding was ready before they went big on it.

Bear in mind that a lot of commercial brewers have incorporated rehydration into SOPs and so it would inconvenience their customers for Fermentis to deprecate rehydration, hence the slightly weird advice to sprinkle or rehydrate, they're easy either way.

 

[hilts]

I still don't see why you would not hydrate. Get a plastic bottle of water from the store at room temp. Pour out half. Add dry yeast. Shake it up. Pitch in 30 minutes.

 

[z-bob]

Saturday I rehydrated a 3 year old packet of Nottingham, as much as anything to make sure it was still good. I put it in a 5 ounce glass with 2 ounces of 90 degree tapwater and set a Pringles lid on top. 15 minutes later I checked on it, and it had foamed out the top and knocked the lid off and had 4 fruitflies on it. I scraped off the top and pitched what was left; I figure I lost well over half of it. The beer is fermenting just fine now, but the lag time was about 18 hours.

If I ever do this again, I'll use a 16 ounce jar, so when it foams up it will stay in the jar. Then I can add a little wort and give it another 10 minutes to get used to the sugar and so the temperature will be closer when I pitch it.

If I'm sure the yeast packet is fresh, think I'll just sprinkle it on top next time. I still think proofing old yeast is a good idea, I just executed it poorly.

 

[jfolks]

Weren’t the E2U trials (that found similar results for dry vs rehydrated pitches) conducted on wine?

 

[BrewnWKopperKat]

Weren’t the E2U trials (that found similar results for dry vs rehydrated pitches) conducted on wine?

Have you seen this article? BREWING WITH E2U™ No more rehydration needed

 

[BrewnWKopperKat]

I still don't see why you would not hydrate. Get a plastic bottle of water from the store at room temp. Pour out half. Add dry yeast. Shake it up. Pitch in 30 minutes.

When I started homebrewing with a couple of kits, I pitched the yeast dry and got good results. About once a year, I'd try rehydrating - but never noticed a difference. I tried the technique you mentioned as well (I yeard about it in a HomeBrew Con 2016 presentation) - again, didn't notice a difference.

Fermentis, Lallemand, and Mangrove Jacks all have information on pitching dry yeast without rehydrating and on how to rehydrate. So, for me, it's pretty much a personal preference as to which way to pitch the yeast. I'll bring the appropriate links forward

However if you are curious they do also provide more detailed instructions on their websites.

https://fermentis.com/wp-content/uploads/2017/10/SafAle-US-05.pdf
- describes 45-60 min rehydration process in detail
- provides direct sprinkle method as alternative

http://www.lallemandbrewing.com/docs/products/bp/BEST-PRACTICES_REHYDRATION_DIGITAL.pdf
- rehydration is preferred and provides detailed techniques

https://cdn.shopify.com/s/files/1/0...68-8d16-673b5fb84f75.pdf?16489226078703376035
- Mangrove Jack's buries the information in the detailed instructions...see page 3

with a thank you to @eric19312 for the link on pitching Lallemand without rehydrating.

 

[ebbelwoi]

Since I'm afraid I'll kill half of the cells by direct pitching, if I'm hoping to keep esters and phenols low, I'll rehydrate. If I want some esters and phenols, for example in a hefeweizen or a particular cider, I'll direct pitch.