Viability of dry yeast?

[Osborne]

I'm ordering the Imperial Stout Kit from Northern Brewer. I plan on pitching two packets of Safeale S-04 directly into the fermentor, and to make sure I decided to check MrMalty. But it's asking for the viability of the yeast? Whats the best way to estimate this?

Thanks!

 

[Chrisbrewbeers]

Just pitch it and don't worry, dry yeast is way more stable than liquid yeast. Viability is most likely fine from them no matter of shipping or anything. My biggest concern would be fermentation temperature with so-4 it might work out in a stout but I didn't like that yeast the one time I used it.

 

[Subdivisions]

Re-hydrate it before pitching. It'll give you more healthy yeast than pitching dry. Mr Malty is fine for figuring out starters but as long as the yeast packet isn't past date then don't worry about it. Two packs of S-04 is fine for that beer.

 

[Osborne]

Just pitch it and don't worry, dry yeast is way more stable than liquid yeast. Viability is most likely fine from them no matter of shipping or anything. My biggest concern would be fermentation temperature with so-4 it might work out in a stout but I didn't like that yeast the one time I used it.

I have a chest freezer with a temparture comtroller. Alrigjt and pitching dry doesn't hurt viability?

 

[Osborne]

Re-hydrate it before pitching. It'll give you more healthy yeast than pitching dry. Mr Malty is fine for figuring out starters but as long as the yeast packet isn't past date then don't worry about it. Two packs of S-04 is fine for that beer.

Rehydrating seems easy to screw up if you don't have a good thermometer. That's why for now did prefer just to pitch two dry packets.

 

[k1ngl1ves]

04 is a beast, so unless OG is super high, you should only need 1 packet of yeast. I rarely rehydrate anymore either. I've never noticed a difference either way. Could be yet another fading homebrewing tradition... like secondaries. Lol!




04 is quite possibly my favorite yeast variety.

 

[Osborne]

04 is a beast, so unless OG is super high, you should only need 1 packet of yeast. I rarely rehydrate anymore either. I've never noticed a difference either way. Could be yet another fading homebrewing tradition... like secondaries. Lol!




04 is quite possibly my favorite yeast variety.

The OG is 1.086 so that's why I figure getting two. Yeah I haven't used a secondary either, I don't see the point couldn't I just secondary in the keg I plan on using? Only down side I could see is the beer wouldn't be as clear but my Irish Red Ale I did last was pretty beautiful.

 

[kombat]

I have a chest freezer with a temparture comtroller. Alrigjt and pitching dry doesn't hurt viability?

Yes, pitching dry absolutely impacts viability. It diminishes it by up to 50%. You should always rehydrate dry yeast according to the manufacturer's instructions prior to pitching. From the Fermentis website:

"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."

Rehydrating seems easy to screw up if you don't have a good thermometer.

How are you making beer without a good thermometer?

That's why for now did prefer just to pitch two dry packets.

I suppose that's better than dry-pitching a single pack, but rehydrating 2 would be even better still. Are you going for drinkable beer, good beer, or the best beer you can make?

You're starting with a high O.G. of 1.086. The rule of thumb for yeast is 4 billion cells per point of gravity per 5 gallon batch of ale. So a 5 gallon batch of 1.086 wort would require 344 billion cells of ale yeast. One packet of dry yeast has the potential of up to 200 billion cells. So if you rehydrated, and the yeast was perfectly viable, you'd be slightly overpitching. But by pitching 2 packs dry, reducing cell viability by up to 50%, you'd be pitching at most 200 billion cells (less if the yeast was a little older), or an underpitch of 42%.

Like I said, it will still be beer, but I'd be concerned about underpitching by such a large margin, particularly when the solution (rehydrating) is so trivially easy.

Get yourself a nice Thermapen.

 

[Osborne]

Yes, pitching dry absolutely impacts viability. It diminishes it by up to 50%. You should always rehydrate dry yeast according to the manufacturer's instructions prior to pitching. From the Fermentis website:

"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 in the fermentation vessel."



How are you making beer without a good thermometer?


I suppose that's better than dry-pitching a single pack, but rehydrating 2 would be even better still. Are you going for drinkable beer, good beer, or the best beer you can make?

You're starting with a high O.G. of 1.086. The rule of thumb for yeast is 4 billion cells per point of gravity per 5 gallon batch of ale. So a 5 gallon batch of 1.086 wort would require 344 billion cells of ale yeast. One packet of dry yeast has the potential of up to 200 billion cells. So if you rehydrated, and the yeast was perfectly viable, you'd be slightly overpitching. But by pitching 2 packs dry, reducing cell viability by up to 50%, you'd be pitching at most 200 billion cells (less if the yeast was a little older), or an underpitch of 42%.

Like I said, it will still be beer, but I'd be concerned about underpitching by such a large margin, particularly when the solution (rehydrating) is so trivially easy.

Get yourself a nice Thermapen.

I use a meat thermometer to tell when to pull the speciality grains out it is accurate enough for that but I don't think it tells the temparture until around 110 or 120.

Darn this is what I was afraid of and why I was asking. May I ask why some dry yeast says not to rehydrate? If it's going to kill 50% of the cells?

 

[Chrisbrewbeers]

I have a chest freezer with a temparture comtroller. Alrigjt and pitching dry doesn't hurt viability?

I just hated the one time I used so-4 so much that I would tell you that, I think it got into the 70's. If you have chest freezer, (which I don't yet) that might work out. I do see why you might worry about viability with 1.086 OG but I wouldn't. I've seen so many threads saying bad things about s-04 I feel like.

 

[Chrisbrewbeers]

I use a meat thermometer to tell when to pull the speciality grains out it is accurate enough for that but I don't think it tells the temparture until around 110 or 120.

Darn this is what I was afraid of and why I was asking. May I ask why some dry yeast says not to rehydrate? If it's going to kill 50% of the cells?

They probably consider it an opportunity for something to go wrong that isn't really necessary. I have only rehydrated once out of lots of times and can't see the difference. Don't trust me though other people likely have better answer. It seems like a really debatable thing as far as my research.

 

[kombat]

May I ask why some dry yeast says not to rehydrate?

I don't know of any dry yeast that specifically instructs NOT to rehydrate.

I understand that the instructions that come with some kits that include dry yeast advise you to just sprinkle it in dry, but the yeast package itself is either completely blank (a plain, foil pouch), or a standard dry yeast, none of which I'm aware include any directives NOT to rehydrate.

 

[Subdivisions]

I think it's like what Chris is saying, they want to reduce the chance of eff ups by newer brewers. If your thermometer is off or you didn't sterilize your water then you could have dead yeast or possible infection. I know Safale has instructions for both pitching dry and re-hydrating. There may be times where you actually WANT to stress the yeast to produce different esters.

I have pitched dry before and the beer turned out fine but I find that it takes off quicker when re-hydrated.

In the OPs beer though with a high gravity I think it's better to re-hydrate and have the most yeast cells possible. You risk an under attenuated or stalled fermentation by stressing the yeast

 

[Osborne]

I don't know of any dry yeast that specifically instructs NOT to rehydrate.

I understand that the instructions that come with some kits that include dry yeast advise you to just sprinkle it in dry, but the yeast package itself is either completely blank (a plain, foil pouch), or a standard dry yeast, none of which I'm aware include any directives NOT to rehydrate.

Your correct I checked the packaging, it seems I read that on the instructions for the kit.

 

[Osborne]

Edit

 

[Osborne]

I think it's like what Chris is saying, they want to reduce the chance of eff ups by newer brewers. If your thermometer is off or you didn't sterilize your water then you could have dead yeast or possible infection. I know Safale has instructions for both pitching dry and re-hydrating. There may be times where you actually WANT to stress the yeast to produce different esters.

I have pitched dry before and the beer turned out fine but I find that it takes off quicker when re-hydrated.

In the OPs beer though with a high gravity I think it's better to re-hydrate and have the most yeast cells possible. You risk an under attenuated or stalled fermentation by stressing the yeast

I may just have to wait and do high gravity beers once I get a good thermometer. Another issue is I brew outside, so rehydrating the yeast maybe a issue... The ground water even in summer is cold here so my wort is within pitching temps in 10 minutes using my chiller. I guess it wouldn't hurt for it to set 30 more minutes before pitching yeast, especially since it will be taking off faster...

 

[Osborne]

Any recommendations on a good quality reasonably priced thermometer?

 

[stratslinger]

I may just have to wait and do high gravity beers once I get a good thermometer. Another issue is I brew outside, so rehydrating the yeast maybe a issue... The ground water even in summer is cold here so my wort is within pitching temps in 10 minutes using my chiller. I guess it wouldn't hurt for it to set 30 more minutes before pitching yeast, especially since it will be taking off faster...

Not to nitpick here but - how do you know you're at pitching temps if you don't have a good thermometer? What are you using to measure that? Shouldn't you be able to just use that same measuring device to measure your water temp for rehydrating?

But before you get too paranoid about the temp - I feel like the temp ranges specified on that package are a little more narrow than they need to be. Chris White, in his book Yeast, suggests ~100F for rehydrating all dry yeasts, then adjusting the temp to +/- 5F of pitching temp... And I've read a few other varying recommendations by other authorities as well.

Based on the wide range of recommended temps, I usually forgo measuring rehydrating water anyway - I simply take water that feels slightly warm (you're looking for at or slightly above body temp) off the tap, and go with that. Hasn't failed me yet - if there's any nasties in my tap water, they've consistently been outcompeted by the yeast.

 

[Osborne]

Not to nitpick here but - how do you know you're at pitching temps if you don't have a good thermometer? What are you using to measure that? Shouldn't you be able to just use that same measuring device to measure your water temp for rehydrating?

But before you get too paranoid about the temp - I feel like the temp ranges specified on that package are a little more narrow than they need to be. Chris White, in his book Yeast, suggests ~100F for rehydrating all dry yeasts, then adjusting the temp to +/- 5F of pitching temp... And I've read a few other varying recommendations by other authorities as well.

Based on the wide range of recommended temps, I usually forgo measuring rehydrating water anyway - I simply take water that feels slightly warm (you're looking for at or slightly above body temp) off the tap, and go with that. Hasn't failed me yet - if there's any nasties in my tap water, they've consistently been outcompeted by the yeast.

The temparture strip on the side of my fermenter always reads in the mid 60s once I top it off. And feeling the side it feels very much so.

Idd probably just boil some spring water, I always have some left in a jug after brewing to be on the safe side. I don't completely trust my tap water although it can't be too bad. I keep StarSan in a sealed food grade bucket for a month or so at a time and it always reminds clear.

 

[Subdivisions]

Any recommendations on a good quality reasonably priced thermometer?

This is the best bang for the buck. It can be calibrated and is water resistant. It's made by Thermoworks who make the Thermapen.

http://www.amazon.com/RT301WA-Super-Fast-Digital-Thermometer-Approval/dp/B002GE9S8I/ref=sr_1_3?ie=UTF8&qid=1440000347&sr=8-3&keywords=thermoworks+rt600

 

[Osborne]

This is the best bang for the buck. It can be calibrated and is water resistant. It's made by Thermoworks who make the Thermapen.

http://www.amazon.com/RT301WA-Super-Fast-Digital-Thermometer-Approval/dp/B002GE9S8I/ref=sr_1_3?ie=UTF8&qid=1440000347&sr=8-3&keywords=thermoworks+rt600

Thanks I've ordered one.

 

[Osborne]

So how much water would be 10x two packs? I'm guessing I can just heat the water in the microwave ? I'll be heating in a container cleaned and sanitized the same way anything else touches my beer, and using the same bottled spring water I top off my fermenter with.

 

[stratslinger]

Do you have a decent scale? The packs are typically 11g, so you'd want 220g of water - the volume of 220g of water can vary a bit with temperature, so it's _most_ accurate to weigh the water on a decent scale.

That said - roughly about a pint of water will do - the weight thing is absolute ideal conditions, but I haven't found it to be completely necessary. You just want to make sure there's enough surface area in the water so you can sprinkle a fairly uniform layer of yeast across the surface, and you don't have a ton of clumps.

 

[Osborne]

Do you have a decent scale? The packs are typically 11g, so you'd want 220g of water - the volume of 220g of water can vary a bit with temperature, so it's _most_ accurate to weigh the water on a decent scale.

That said - roughly about a pint of water will do - the weight thing is absolute ideal conditions, but I haven't found it to be completely necessary. You just want to make sure there's enough surface area in the water so you can sprinkle a fairly uniform layer of yeast across the surface, and you don't have a ton of clumps.

Gotcha I was considering using a 6-8 ounces in a large Pyrex measuring cup. I have no scale, although I've been wanting one.

 

[kombat]

Do you have a decent scale? The packs are typically 11g, so you'd want 220g of water - the volume of 220g of water can vary a bit with temperature, so it's _most_ accurate to weigh the water on a decent scale.

Come on. Are you serious?

At room temperature (20° C), 220g of water will be exactly 220 mL. Even if it were boiling hot, it would only be off by a trivial amount. Just use a little graduated beaker and measure out roughly 220 mL of water. The yeast aren't *that* picky about how much water you rehydrate them in. If you were totally sloppy and used 230 mL of water, there'd be no perceptible difference at all. Weighing the water is gross overkill.

the weight thing is absolute ideal conditions, but I haven't found it to be completely necessary.

I'll do you one better: it's completely unnecessary.

 

[stratslinger]

I'll do you one better: it's completely unnecessary.

Touche

 

[DarkStarNJ]

It would likely be less confusing if the package and the advice given from HBT was the same. not saying what is right or wrong.

But Fermentis does have directions directly on the package. And it's pretty clear what it is. Perhaps they just don't want to lose business of lazy brewers...

https://bellsbeer.com/store/product_images/f/272/IMG_4069-001__32023_zoom.JPG
http://www.norcalbrewingsolutions.c...ts/Yeast/0096-Safale-US-05-Dry-Yeast-Logo.jpg

 

[kombat]

Perhaps they just don't want to lose business of lazy brewers.

I think it's more that they don't want to scare off new brewers with seemingly complicated rehydration procedures. Any research I've seen on the subject (OK, I read the book "Yeast") unequivocally concludes that the best way to maximize yeast viability is by following the manufacturer's instructions for rehydration, and that sprinkling dry can reduce cell viability by up to 50%.

The more conspiracy-theory minded claim that the manufacturers just want to sell more yeast (it takes 2 packs sprinkled dry to equal the viable cell count of 1 pack properly rehydrated).

That said, sprinkling 1 pack dry will always produce beer. It just may not be the most "optimal" beer, as the yeast will experience more stress than if they'd been properly prepared.

 

[ncbrewer]

The Fermentis website also says that if you are pitching the yeast dry, the wort should be above 68F - I figure it would be around 70F to be safe. I don't like pitching that warm.

 

[Puddlethumper]

The Fermentis website says:

"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."

Following these instructions is a very simple process and, if you have a decent thermometer and a measuring cup it is pretty hard to screw it up:

I always heat 10 gal. of brewing water in my hot liquor tank in preparation for brewing. After mashing and sparging there is always at least a few quarts of nice warm water left in the bottom. That water has been heated to +/- 175F for sparging so it has been thoroughly pasteurized. I pull "at least" 10x the weight of my dry yeast with a small sterilized measuring cup or beaker, cover it with foil that has been sprayed with StarSan, and let it cool to 80F (+/- 6F). Then simply pitch the yeast into it per Fermentis' instructions.

Having a stir-plate does help with the stirring for 30 minutes. But you can stir it with a sterilized spoon every once in a while and achieve satisfactory results.

To cool the slurry put it in the fridge for a bit until its temperature drops to within 5-10F of your wort and it's ready to pitch.

Cheers!

 

[ncbrewer]

The Fermentis website says:

"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."

This part of the website http://en.calameo.com/read/0026934555f07e32293ea says "Gently stir and leave for 30 minutes." I don't know why the disagreement on their website, but these instructions eliminate the need for a stir plate.

 

[Osborne]

Darn, I noticed that ... I really don't think I'll stir for a entire 30 minutes...

Does anyone really do that without a stir plate?

 

[Puddlethumper]

This part of the website http://en.calameo.com/read/0026934555f07e32293ea says "Gently stir and leave for 30 minutes." I don't know why the disagreement on their website, but these instructions eliminate the need for a stir plate.

I had read those instructions in the past but didn't realize they were still on their site. Thought they had updated their instructions but perhaps not. Interesting.

 

[Osborne]

I had read those instructions in the past but didn't realize they were still on their site. Thought they had updated their instructions but perhaps not. Interesting.

So do I have to stir the entire 30 minutes....? Will I be fine just stirring a bit then letting it sit?

 

[Puddlethumper]

So do I have to stir the entire 30 minutes....? Will I be fine just stirring a bit then letting it sit?

According to the manufacturer's latest instructions it is the best practice. I suspect that if you rehydrate according to their instructions and then after 30 minutes give it a swirl every now and then for another half hour you'll probably end up OK. They do give alternate instructions to sprinkle it dry into the wort. How much difference it will ultimately make is anybody's guess.

Cheers!

 

[Puddlethumper]

This part of the website http://en.calameo.com/read/0026934555f07e32293ea says "Gently stir and leave for 30 minutes." I don't know why the disagreement on their website, but these instructions eliminate the need for a stir plate.

It appears that site has saved old instructions that have since been updated by Fermentis.

Cheers!

 

[ncbrewer]

Another part of the Fermentis website (actually brewwithfermentis.com) - http://www.brewwithfermentis.com/tips-tricks/yeast-rehydration/ says:
Rehydration is a simple procedure.

Rehydrate the yeast in 10 times its weight of water or wort. Gently stir. Allow a 30 minutes rest. Pitch the resultant cream in the fermenter.

They can't seem to make up their minds. This might be more of the outdated info - don't know. I've been using Danstar's rehydration procedure (but using the Fermentis temperature reco on Fermentis yeast) and like the results. I really think there are several methods that will work well, but constant stirring doesn't seem to be necessary IMO.

 

[Puddlethumper]

They can't seem to make up their minds......
I really think there are several methods that will work well, but constant stirring doesn't seem to be necessary IMO.

Agreed. I used their old method for many batches of beer and they all turned out well. A couple months ago I was double checking the fermentation temperature recommendations and ran across these new instructions. The new procedure does make a very nice slurry. But it is also best done if you happen to have a stir-plate.

 

[Osborne]

Another part of the Fermentis website (actually brewwithfermentis.com) - http://www.brewwithfermentis.com/tips-tricks/yeast-rehydration/ says:
Rehydration is a simple procedure.

Rehydrate the yeast in 10 times its weight of water or wort. Gently stir. Allow a 30 minutes rest. Pitch the resultant cream in the fermenter.

They can't seem to make up their minds. This might be more of the outdated info - don't know. I've been using Danstar's rehydration procedure (but using the Fermentis temperature reco on Fermentis yeast) and like the results. I really think there are several methods that will work well, but constant stirring doesn't seem to be necessary IMO.

I believe I'll follow these instructions....