When to pitch rehydrated dry yeast?

So I have re-hydrated 2 packets of dry yeast. I have put 1 cup of boiled water at 35 degrees Celsius into a sanitized jar and added the yeast. Covered it with film and after 15 minutes added 1 tablespoon of sugar that was boiled in a small amount of water. After 30 minutes there is foaming happening in the jar.
My question is when do I pitch this rehydrated yeast to my wort waiting in the fermenting bucket? Is it ok to pitch it now? Any help is appreciated. Thanks.

Now. It really only needs 10 minutes or so to rehydrate. Your yeast should be good and happy now. Go ahead and pitch 'er in.

You should always add some cooled wort a little at a time to the rehydrated yeast to bring the temp down to within 10 degrees of wort temp. Otherwise,the yeast will shock from the temp differential & take longer to get going.

i wouldn't even bother re-hydrating dry yeast. all my batches have been 1.060 or less and not had any problems with 04 or 05 yeast.

unionrdr said:

You should always add some cooled wort a little at a time to the rehydrated yeast to bring the temp down to within 10 degrees of wort temp. Otherwise,the yeast will shock from the temp differential & take longer to get going.

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Can I overcome this problem without adding cooled wort but instead cooling it with ice packs or fridge maybe?

JDGator said:

i wouldn't even bother re-hydrating dry yeast. all my batches have been 1.060 or less and not had any problems with 04 or 05 yeast.

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The thing is I am using standard yeast from a cooking shop. I don't know how it is going to turn out but it is saccharomyces cerevisiae (ale yeast) so it should not turn out that bad.

JDGator said:

i wouldn't even bother re-hydrating dry yeast. all my batches have been 1.060 or less and not had any problems with 04 or 05 yeast.

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Just because you haven't had any problems doesn't mean it couldn't be better.

You're underpitching. A 5 gallon batch of 1.060 ale requires 240 billion yeast cells. One packet of dry yeast contains 100 billion cells. If you pitch it without rehydrating, roughly 50% of the cells do not survive.

So you're pitching 50 billion cells when 240 billion would be optimal. You're only pitching about 20% of the yeast you should be pitching.

This comes from the book "Yeast," by White and Zainasheff.

Standard baking yeast is not ale yeast. Just use some cooled wort out of the fermenter a little at a time to bring the temp down. A properly used start will cut lag time (reproductive phase) & visible fermentation will start sooner.

I would stick to beer yeast for beer and wine yeast for wine. About the only thing I'd use standard bread making yeast for is Joe's Ancient Orange Mead, b/c the recipe was developed with it to match a certain profile.

Why go through all of the work to brew and try to save $3 or 4 for dry ale yeast? Should be okay for this batch, but maybe consider changing from here on out.

unionrdr said:

You should always add some cooled wort a little at a time to the rehydrated yeast to bring the temp down to within 10 degrees of wort temp. Otherwise,the yeast will shock from the temp differential & take longer to get going.

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My rehydrated yeast is already close to the wort temperature. I chill my wort to 65° F, and I rehydrate my yeast with tap water that is around 65-70° F. No need to introduce them to wort prematurely.

Also, you shouldn't add sugar to your rehydrating yeast. They need to be in maltose-munching mode. If you give them cane sugar or beet sugar or corn sugar or anything else, you're selecting for yeast that are not necessarily the best wort-munchers.

Just rehydrate an appropriate quantity for 20 minutes in plain, room-temperature tap water.

atakanokan said:

The thing is I am using standard yeast from a cooking shop. I don't know how it is going to turn out but it is saccharomyces cerevisiae (ale yeast) so it should not turn out that bad.

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What is the ambient temperature where the yeast is? That small amount should not need to be cooled. Personally, I don't think temperature difference is critical. Within 10 degrees should be good.

It is surprising that you found ale yeast at a cooking shop. What they usually carry is not good for brewing beer. Also there are many different ale yeasts and some are good for certain styles of beer and others for some other style. Just pitching an unknown "ale yeast" might not give desired results.

kombat said:

Just because you haven't had any problems doesn't mean it couldn't be better.

You're underpitching. A 5 gallon batch of 1.060 ale requires 240 billion yeast cells. One packet of dry yeast contains 100 billion cells. If you pitch it without rehydrating, roughly 50% of the cells do not survive.

So you're pitching 50 billion cells when 240 billion would be optimal. You're only pitching about 20% of the yeast you should be pitching.

This comes from the book "Yeast," by White and Zainasheff.

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well according to mr. malty, you only require 1.1 packages of 11.5gr for a 1.060 batch. so i'd say your somewhat correct. i need another .5gr.

but i have also seen calculators that say mr. malty is out to lunch.

Here's the PDF from Fermentis on US-05; http://www.midwestsupplies.com/media/downloads/213/safale%20us-05.pdf And I've never used more than 1 packet on a 1.060 wort. One packet usually starts (rehydrated) By the wee hours next morning ime.

kombat said:

You're underpitching. A 5 gallon batch of 1.060 ale requires 240 billion yeast cells. One packet of dry yeast contains 100 billion cells. If you pitch it without rehydrating, roughly 50% of the cells do not survive.

So you're pitching 50 billion cells when 240 billion would be optimal. You're only pitching about 20% of the yeast you should be pitching.

This comes from the book "Yeast," by White and Zainasheff.

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Show us this directly from the book. The 100 billion count is for liquid yeast not dry.

It has also been disproved that dry pitching will automatically kill 50% of the yeast.

I am not saying that re-hydrating is not better, but it is not nearly as bad as stated.

JDGator said:

but i have also seen calculators that say mr. malty is out to lunch.

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Some people think so, MOST do not.

kh54s10 said:

Some people think so, MOST do not.

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i'm by no means an expert of brewing and definetely not when it comes to yeast and yeast counts. but i do know that dry yeast is packaged in 11.5gr packages so you can just pitch it in. if the yeast cell count was so out to lunch, they would raise the quantity and charge more for it.

JDGator said:

well according to mr. malty, you only require 1.1 packages of 11.5gr for a 1.060 batch. so i'd say your somewhat correct. i need another .5gr.

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I may be misinformed regarding the number of cells in a packet of dry yeast.

Regardless, Mr. Malty is assuming 100% viability for dry yeast. As I mentioned, if you're not rehydrating, you're only achieving 50% viability.

JDGator said:

but i have also seen calculators that say mr. malty is out to lunch.

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The accepted formula is 4 billion cells per degree of gravity per 5 gallon batch of ale. That's not a Mr. Malty thing, that's just the industry standard formula. In your case, that's 240 billion cells.

If 1 packet of dry yeast contains 240 billion cells, then I stand corrected. But my understanding is that a packet is equivalent to a liquid yeast smack-pack or vial, and that they all contain 100 billion cells when 100% viable.

Kombat, i really don't have a good arguement with fancy numbers. you could be dead nuts on!!

i'll be honest, i'm not gonna take the time to rehydrate my US-05 or S-04 yeast. if i'm gonna go to that trouble, i'd be better off to by liquid yeast and make a starter. no thanks.

unionrdr said:

Here's the PDF from Fermentis on US-05; http://www.midwestsupplies.com/media/downloads/213/safale%20us-05.pdf And I've never used more than 1 packet on a 1.060 wort. One packet usually starts (rehydrated) By the wee hours next morning ime.

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I didn't say it wouldn't work. I said it wasn't optimal.

Crunching the numbers in the PDF you posted, it appears one 11.5g packet of US-05 at 100% viability contains 69 billion yeast cells. So it's even worse than I thought. If you're not rehydrating, you're only getting 35 billion cells instead of the optimal 240 billion. You're pitching less than 15% of the cells you should be pitching. That will stress the yeast and result in off-flavours.

I'm not making this up - this is all based on the science and research fully explained in the "Yeast" book. Your fermentations will (obviously) still work. The resulting beer simply won't be the best it could be.

JDGator said:

i'll be honest, i'm not gonna take the time to rehydrate my US-05 or S-04 yeast.

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What time? You do it during the boil, when you're waiting around anyway.

JDGator said:

if i'm gonna go to that trouble, i'd be better off to by liquid yeast and make a starter. no thanks.

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Huh??? Did you seriously just compare the complexity of rehydrating dry yeast to preparing a starter?

1.) Dunk glass measuring cup and spoon in Starsan.
2.) Fill with 250 mL of tap water.
3.) Open yeast packet and sprinkle into water.
4.) Stir with sanitized spoon.
5.) Cover with foil and wait 20-30 minutes.
6.) Pour into cooled, aerated wort.

How is that anywhere near as laborious as making a liquid yeast starter?

kh54s10 said:

What is the ambient temperature where the yeast is? That small amount should not need to be cooled. Personally, I don't think temperature difference is critical. Within 10 degrees should be good.

It is surprising that you found ale yeast at a cooking shop. What they usually carry is not good for brewing beer. Also there are many different ale yeasts and some are good for certain styles of beer and others for some other style. Just pitching an unknown "ale yeast" might not give desired results.

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I know that it might not give a desired result but after all it will be beer at the end. I know that yeasts come in all sorts for different kinds of beer, I just wanted to try what happened with the ones that I bought from a cooking shop. How different will it be, we will see.

kombat said:

What time? You do it during the boil, when you're waiting around anyway.



Huh??? Did you seriously just compare the complexity of rehydrating dry yeast to preparing a starter?

1.) Dunk glass measuring cup and spoon in Starsan.
2.) Fill with 250 mL of tap water.
3.) Open yeast packet and sprinkle into water.
4.) Stir with sanitized spoon.
5.) Cover with foil and wait 20-30 minutes.
6.) Pour into cooled, aerated wort.

How is that anywhere near as laborious as making a liquid yeast starter?

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right now i take a pair of fancy scissors, cut the top off the package of yeast, and pour the little fellas down into the wort. pretty quick and simple.

i wrote that in full sentence form and it was shorter then your above method.

also, why sanitize everything and use tap water? i don't understand the point of that?

kh54s10 said:

It has also been disproved that dry pitching will automatically kill 50% of the yeast.

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Who disproved it? I cited my source ("Yeast," by White and Zainasheff) - what's yours?

JDGator said:

right now i take a pair of fancy scissors, cut the top off the package of yeast, and pour the little fellas down into the wort. pretty quick and simple.

i wrote that in full sentence form and it was shorter then your above method.

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The steps I outlined will take you literally less than 2 minutes.

Prepping a liquid starter takes me at least 20 minutes, and that's not counting the time waiting for the stir plate, waiting for the cold-crash, cleaning the flask/stir bar, etc. It's foolish to say the two tasks are of comparable complexity or effort.

JDGator said:

also, why sanitize everything and use tap water? i don't understand the point of that?

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A fair question, I guess I should have added a step for boiling/cooling the water if you're on a well. I'm on city water so my water contains chloramine, which inhibits microbial growth and makes it fine to use for rehydrating yeast.

There are a number of people on here that think Mr malty overpitches. I tend to agree. I wasn't arguing whether it's work or not. just that there are degrees of intensity involved here. And I'd love to read the YEAST book. I bet it's full of interesting lil tidbits. And dry yeast packets have more cells than liquid packets/vials. so those numbers seem a little off. 100B liquid cells & only 69B dry. Nope. If that's there research,they better go back a count'em up again.

kombat said:

The steps I outlined will take you literally less than 2 minutes.

Prepping a liquid starter takes me at least 20 minutes, and that's not counting the time waiting for the stir plate, waiting for the cold-crash, cleaning the flask/stir bar, etc. It's foolish to say the two tasks are of comparable complexity or effort.



A fair question, I guess I should have added a step for boiling/cooling the water if you're on a well. I'm on city water so my water contains chloramine, which inhibits microbial growth and makes it fine to use for rehydrating yeast.

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3 minutes or 20 minutes is my time that could be spent elsewhere. there are millions of people that pitch dry yeast and don't have an issue. would rehydrating it be better, ya sure very well could be.

and foolish to compare the 2? how do you figure? all your missing with the rehyrated yeast is a small amount of DME, stir plate, and bar. still basically the same thing. be like using a carboy vs. bucket. darn close it you ask me.

kombat said:

The accepted formula is 4 billion cells per degree of gravity per 5 gallon batch of ale. That's not a Mr. Malty thing, that's just the industry standard formula. In your case, that's 240 billion cells.

If 1 packet of dry yeast contains 240 billion cells, then I stand corrected. But my understanding is that a packet is equivalent to a liquid yeast smack-pack or vial, and that they all contain 100 billion cells when 100% viable.

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Dry yeast does contain a lot more yeast cells than liquid packages. That is why
MrMalty suggest maybe 1.1 packages of dry yeast and might suggest 3 vials for the same brew. Check it out.

Dry yeast also does not lose viability as quickly with age. That is why you can use a year old packet of dry when liquid would be down to 10% or less after a year.

I was in the understanding that it's better to boil the amount of water needed to rehydrate the yeast, to sanitize it, cool down to yeast safe temps and then sprinkle the yeast, let it do its thing for half hour and then pitch when ready.

What you can get away with is not what would always be called best practices. The dry yeast manufacturers instructions say you can just sprinkle them on, dry, to HOME BREWERS. At the same time they tell pro brewers to rehydrate the same yeast prior to pitching! You gotta wonder why that is? The yeast don't care if I make money selling my beer or not.
A properly sized (and rehydrated) yeast pitched into a well oxygenated correctly cooled and temperature controlled wort will produce better beers with fewer potential problems every time. You can make good beer sprinkling yeasts. You are just opening your beer up to more problems.

I recently brewed a beer that was 1.058. I used beersmith, mr.malty, and brewers friend yeast calc and all of them suggested 2 packets of dry. This was the first time I've ever pitched two packets of dry into a beer and its the first time I've had to use a blow off tube for dry yeast.

Magic8Ball said:

What you can get away with is not what would always be called best practices. The dry yeast manufacturers instructions say you can just sprinkle them on, dry, to HOME BREWERS. At the same time they tell pro brewers to rehydrate the same yeast prior to pitching! You gotta wonder why that is? The yeast don't care if I make money selling my beer or not.
A properly sized (and rehydrated) yeast pitched into a well oxygenated correctly cooled and temperature controlled wort will produce better beers with fewer potential problems every time. You can make good beer sprinkling yeasts. You are just opening your beer up to more problems.

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i was unable to find where it says homebrewer or pro brewer in the Fermentis instructions. Do you have a link? i was looking in the link Uniondr posted.

Look at the 2nd paragraph under pitching instructions in the link I posted. Those two paragraphs say it all.

bennie1986 said:

I recently brewed a beer that was 1.058. I used beersmith, mr.malty, and brewers friend yeast calc and all of them suggested 2 packets of dry. This was the first time I've ever pitched two packets of dry into a beer and its the first time I've had to use a blow off tube for dry yeast.

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You may have read the page wrong. I just went to Mrmalty and it says 2.4 packets at 5 grams and 1 packet at 11.5 grams.

I put in a production date of April 17.

BTW I always start fermenting with a blow off tube installed and I have never had to do a big cleanup. And I have had a lot of blow-offs.

So far as blow offs are concerned,I've needed them even when using a rehydrated 7g packet of Cooper's ale yeast. so it's all relative to a healthy yeast pitch.

unionrdr said:

So far as blow offs are concerned,I've needed them even when using a rehydrated 7g packet of Cooper's ale yeast. so it's all relative to a healthy yeast pitch.

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I have done very similar (not exactly the same) recipes and pitched the same yeast in the same sized starters,and fermented at the same temperature. One will blow-off and the other will not. The yeast will do what they want regardless of what you do.

kh54s10 said:

You may have read the page wrong. I just went to Mrmalty and it says 2.4 packets at 5 grams and 1 packet at 11.5 grams.

I put in a production date of April 17.

BTW I always start fermenting with a blow off tube installed and I have never had to do a big cleanup. And I have had a lot of blow-offs.

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Malty said 1.4 of 11.5 packets, my production date was 7/12. The other calcs just said two packets but I'm sure they were just rounding up. Oh and I did rehydrate.

JDGator said:

i was unable to find where it says homebrewer or pro brewer in the Fermentis instructions. Do you have a link? i was looking in the link Uniondr posted.

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Ill be *amed they changed the instructions . It now says to rehydrate or sprinkle for the homebrewers too. I wonder when they changed that? I guess you will have to take my word that they used to have two different instructions. Still doesn't change the fact you are losing 50% of your yeast if you sprinkle instead of rehydrating. Go read pgs 146 & 147 of "Yeast" by Jamil Zainasheff and Chris White.

From the Fermentis website:
" rehydration instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°c ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle
the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the
wort using aeration or by wort addition."

i read the fermentis instructions 2-3 times in full that's why i asked for a link. why would i read someone elses book on yeast when the company who's yeast it is, tells me what to do.

we may just have to agree to disagree