Pitching Rate for s-04

[MKBoitnott]

Hello everyone,

So I recently did a 3-gal batch (1.050) of beer and pitched some s-04. Like many of you, I went on the mrmalty.com to get my pitching rate. According to JZ, I needed 6 grams of dry yeast to get my numbers. JZ estimates that dry yeast packets have a density of 20 billion cells per gram (230 billion for an 11.5g packet).

Today I was doing some research on dry yeast and I stumbled some dramatically different information. For example, a study listed by brewersfriend.com (http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/#cells_per_gram) claims that s-04 and s-05 packets only have a density of 8 billion cells per gram (92 billion for an 11.5g packet). I found some other sites that support this number. Moreover, the Fermentis website lists the density at 6 billion (69 billion for an 11.5g packet).

Whether the number is 6 or 8, it appears that I may have dramatically underpitched my beer. I am not too concerned about it right now, but I was wondering if any of you have found more information to help with this contradiction. When brewing larger batches with dry yeast, it seems these numbers could really affect the quality of your beer. Ex: needing 400 billion cells for a 1.050 11gal batch, and only pitching 200 billion based on the Fermentis and Brewersfriend website.

 

[bethebrew]

Recently I did an IPA that was 1.070 starting gravity. Ended up with two carboys each having a little over 5 gallons. Pitched one old outdated pack of S-04 each and fermented at 62-64F as measured between the two carboys near top of liquid. Fermentation took off after about 24 hours and was vigorous enough to bring some foam up full sized blowoff tube and into the sanitizer in a mason jar.

It's a super vigorous yeast, that finishes fast when fermented at desirable low 60s.

 

[osagedr]

I've always assumed 20 billion cells per gram, properly rehydrated, and never had trouble. But I'll look at the link you provided.

 

[MKBoitnott]

I had a vigorous fermentation as well. Hit my FG in 4 days. However, I was under the impression that the speed and vigorousness of your fermentation might not be related to your cell count. And especially after brewing 3 gal, I would think that I would still get a vigorous fermentation if I underpitched (the disparity would be less amplified with a smaller batch).

My question is less about a concern about my current beer, and more about the general question of pitching rates for dry yeast.

 

[bethebrew]

I had a vigorous fermentation as well. Hit my FG in 4 days. However, I was under the impression that the speed and vigorousness of your fermentation might not be related to your cell count. And especially after brewing 3 gal, I would think that I would still get a vigorous fermentation if I underpitched (the disparity would be less amplified with a smaller batch).

My question is less about a concern about my current beer, and more about the general question of pitching rates for dry yeast.

From my experience, having used dry yeasts including many "outdated packages" that I keep refrigerated, and focusing almost exclusively on big 7% ABV beers, one pack sprinkled into the wort works great. Now, just to be clear, I don't do lagers if that's in question then yeah add more. But for the ales using S-04 and US-05 at low 60s, never an issue. If the ferment has taken off after less than a day, that's good enough in my world.

 

[BigFloyd]

Are you rehydrating your dry yeast like S-04 before pitching?

As far as I know at this point, an 11g pack of rehydrated ale yeast is sufficient cells for 5 gallons of wort up to 1.060. For a lager of that gravity, double the cell count.

 

[MKBoitnott]

Are you rehydrating your dry yeast like S-04 before pitching?

As far as I know at this point, an 11g pack of rehydrated ale yeast is sufficient cells for 5 gallons of wort up to 1.060. For a lager of that gravity, double the cell count.

I did rehydrate the 6 grams of yeast. Seems like I should just take the "wait and see" approach. If I get good results then it is just fine.

Or... I could switch to liquid.

 

[bethebrew]

I did rehydrate the 6 grams of yeast. Seems like I should just take the "wait and see" approach. If I get good results then it is just fine.

Or... I could switch to liquid.

The instructions call for sprinkling the DRY yeast into the wort. Not sure why so many want to waste time, add water and a potential for contamination to fresh wort, when it's so easy just to dump the pack into the wort.

These supposedly accurate programs for how much yeast you need seem extremely conservative. The proof is in the pudding, or in this case beer, and having pitched probably 60 or more dry packs of yeast into 5 gallon batches of usually big beers, and having great success with that approach, I say continue with following Safeale's own directions. Not some guy who did a very questionable study with some really hard to imagine extra viability from rehydrating yeast first. I actually read the study in question and he did a lousy job. Course now it's gospel to many.

 

[MKBoitnott]

These supposedly accurate programs for how much yeast you need seem extremely conservative. The proof is in the pudding, or in this case beer, and having pitched probably 60 or more dry packs of yeast into 5 gallon batches of usually big beers, and having great success with that approach

I guess thats the beauty of homebrewing. If works for you then why change it.

 

[osagedr]

The instructions call for sprinkling the DRY yeast into the wort. Not sure why so many want to waste time, add water and a potential for contamination to fresh wort, when it's so easy just to dump the pack into the wort.

These supposedly accurate programs for how much yeast you need seem extremely conservative. The proof is in the pudding, or in this case beer, and having pitched probably 60 or more dry packs of yeast into 5 gallon batches of usually big beers, and having great success with that approach, I say continue with following Safeale's own directions. Not some guy who did a very questionable study with some really hard to imagine extra viability from rehydrating yeast first. I actually read the study in question and he did a lousy job. Course now it's gospel to many.

You've had "great success?" How do you define that? I mean compared to three-time Ninkasi winner Gordon Strong who recommends rehydration, as do Chris White and Jamil Zainasheff in "Yeast."

The first line of the S-04 product sheet instructions are as follows: "Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27 degrees C +/- 3 degrees C (80 degrees F +/- 6 degrees F). Leave to rest 15-30 minutes. Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel." There are then alternate instructions provided for just sprinkling without rehydrating. Note that in that case the wort is to be left for 30 minutes then mixed--it's not just a case of sprinkle-and-forget.

Bottom line is that rehydrating is the superior method of inoculating your wort with dry yeast and hopefully most people will pay attention to the scientists and award-winning brewers who advise following this practise.

 

[bethebrew]

You've had "great success?" How do you define that? I mean compared to three-time Ninkasi winner Gordon Strong who recommends rehydration, as do Chris White and Jamil Zainasheff in "Yeast."

The first line of the S-04 product sheet instructions are as follows: "Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27 degrees C +/- 3 degrees C (80 degrees F +/- 6 degrees F). Leave to rest 15-30 minutes. Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel." There are then alternate instructions provided for just sprinkling without rehydrating. Note that in that case the wort is to be left for 30 minutes then mixed--it's not just a case of sprinkle-and-forget.

Bottom line is that rehydrating is the superior method of inoculating your wort with dry yeast and hopefully most people will pay attention to the scientists and award-winning brewers who advise following this practise.

I define "great success" in my case with a score of 48 for my American IPA, 44 for my American barleywine, and 44 for my American stout. This in BJCP judged events, where no one else has scored higher than a 36. In all three cases, with one pack of US-05 pitched dry into the carboy. So when you provide me some real evidence it makes a damn bit of difference in the finished product, then perhaps I will believe your reply a little more.

PS I always give the carboy a little shake after a bit to mix in the yeast, but the notion that rehydrating is somehow "superior", when even the manufacturer says it isn't necessary, is clearly silly. Plus, it adds water, and a chance for contamination. Neither are desirable.

 

[osagedr]

I define "great success" in my case with a score of 48 for my American IPA, 44 for my American barleywine, and 44 for my American stout. This in BJCP judged events, where no one else has scored higher than a 36. In all three cases, with one pack of US-05 pitched dry into the carboy. So when you provide me some real evidence it makes a damn bit of difference in the finished product, then perhaps I will believe your reply a little more.

PS I always give the carboy a little shake after a bit to mix in the yeast, but the notion that rehydrating is somehow "superior", when even the manufacturer says it isn't necessary, is clearly silly. Plus, it adds water, and a chance for contamination. Neither are desirable.

I didn't know there was a Special Olympics for brewing.

 

[+HopSpunge+]

Yeast fight.

 

[MKBoitnott]

Judging by the conversation going off-topic, it seems that no one really knows about pitching rate for dry yeast packets. Guess Ill have to buy a microscope and do some counting. Now I just need some homebrewed beer to help me out...

 

[mchrispen]

Based on my observations, the OP has hit the areas where there seems to be some disagreement between the tools we all use to figure pitching rates, and it gets worse with dry yeast recommendations, SG requirements, and possible mishandling of the yeast before pitching. I also just completed a 3 gallon BIAB batch to spilt into 3 single gallon ferments - at half, control and double pitch rates. I am striving to make the best quality beer I can... And pitching the precise required amount will also allow me to make baseline adjustments to shape the flavor expression I am after.

Using 1 gallon at 1.065 gravity:

BeerSmith basically says to pitch a package, despite the resulting over pitch. I am sure it was not designed for small batches, or division of a sachet.

MrMalty put the pitch rate precisely at .2 sachets, which magically means 1 full sachet (11.5 grams) for a 5 gallon batch. .

Brewers Friend had the most customizable interface, and allows the user to input yeast density... which can vary between manufacturers. It also presents options - I chose Pro pitching for high gravity beers. With my SG at 1.065, I was intentionally beyond the 1.040 average gravity I have read about so much. This was also the closest to what I could decode as Fermentis' recommended rates. FYI - I went with 3.3 grams per gallon wort at 1.065. Hydrated as per Fermentis instructions in warm sterile water, I had significant fermentation in just a few hours. The over pitch was going within 1 hour and hard blow off at 3. Will post the results and write up when everything is completed and analyzed.

Source yeast cell density, viability, Fermentation volume AND gravity should dictate the pitch rate. I believe many of these issues are tied to packaging sizes and the need to make yeast pitching as simple and foolproof as possible for the home brewer, and balancing the economics of a highly delicate product that may be mishandled, abused or expire before used.

I need to reread "Yeast" and see if there is any more clarity.

 

[MKBoitnott]

Based on my observations, the OP has hit the areas where there seems to be some disagreement between the tools we all use to figure pitching rates, and it gets worse with dry yeast recommendations, SG requirements, and possible mishandling of the yeast before pitching. I also just completed a 3 gallon BIAB batch to spilt into 3 single gallon ferments - at half, control and double pitch rates. I am striving to make the best quality beer I can... And pitching the precise required amount will also allow me to make baseline adjustments to shape the flavor expression I am after.

Using 1 gallon at 1.065 gravity:

BeerSmith basically says to pitch a package, despite the resulting over pitch. I am sure it was not designed for small batches, or division of a sachet.

MrMalty put the pitch rate precisely at .2 sachets, which magically means 1 full sachet (11.5 grams) for a 5 gallon batch. .

Brewers Friend had the most customizable interface, and allows the user to input yeast density... which can vary between manufacturers. It also presents options - I chose Pro pitching for high gravity beers. With my SG at 1.065, I was intentionally beyond the 1.040 average gravity I have read about so much. This was also the closest to what I could decode as Fermentis' recommended rates. FYI - I went with 3.3 grams per gallon wort at 1.065. Hydrated as per Fermentis instructions in warm sterile water, I had significant fermentation in just a few hours. The over pitch was going within 1 hour and hard blow off at 3. Will post the results and write up when everything is completed and analyzed.

Source yeast cell density, viability, Fermentation volume AND gravity should dictate the pitch rate. I believe many of these issues are tied to packaging sizes and the need to make yeast pitching as simple and foolproof as possible for the home brewer, and balancing the economics of a highly delicate product that may be mishandled, abused or expire before used.

I need to reread "Yeast" and see if there is any more clarity.

Now thats the kind of answer that I was looking for. I ran into these exact problems with each of these programs. Cant wait to hear the results. The fate of my beer hangs in the balance!!

 

[Wynne-R]

Way to go Matt. Actual facts! A novel approach.

It’s nice to know Bastrop didn’t completely burn up.

“Yeast” didn’t say a lot about dry yeast. They recounted the rehydration procedure and stressed that pitching dry yeast onto the wort will kill half of them. Apparently they die horribly.

Besides having only half as much yeast as is needed, the dead cells immediately begin to break down and affect the beer flavor.

They go on to say that the only good reason to not rehydrate is if your sanitation is so terrible that you would introduce wild yeast or bacteria.

 

[BigFloyd]

Way to go Matt. Actual facts! A novel approach.

It’s nice to know Bastrop didn’t completely burn up.

I just drove through there on my way back from San Antonio last Friday and grabbed a bite to eat at Popeye's Chicken. Some burnt areas can be seen driving along Hwy 21 north of town, but it was nice to see that many parts were spared from the ravages of that big nasty fire. That's such a pretty region.

 

[mchrispen]

Thanks guys, and yes, we are happily recovering from those fires... it was pretty grim there for a long time. The pine forest is in terrible shape still - and will take decades to recover. Next time ya'll are through - stop by the Bastrop Brewhouse downtown by the river - great local beer and good food, especially their Alley B Pale Ale, and That's What She Said Stout (chocolate).

You can follow my experiment at my blog if you want to play along. Happy for comments or suggestions as well. As for scientific data, of course, I am not a lab and can already see some flaws in my experiment. Still - it should be at least another data point, even if it is only relevant to how I conducted the experiment. That said - I still want a reliable baseline to work from - and I believe that always using MrMalty, BeerSmith or other provides that baseline for some people. I happen to want to emulate pitching rates at commercial breweries because I believe (possibly mistaken) that they pitch at higher rates, have more consistency than most homebrewers in their pipeline processes, and can replicate their process consistently. Seems like a good goal for a homebrewer.

Let me add - I don't want to fuel a fight over rehydration of dry yeast or liquid vs. dry yeast... that has been hashed over and over. Let's agree that healthy yeast at the right pitching rate is great insurance against off flavors and stuck fermentation and gives the beer the best chance to be great.

 

[Frazeart]

Just subscribed to your blog. SCIENCE!!!!!

Thanks guys, and yes, we are happily recovering from those fires... it was pretty grim there for a long time. The pine forest is in terrible shape still - and will take decades to recover. Next time ya'll are through - stop by the Bastrop Brewhouse downtown by the river - great local beer and good food, especially their Alley B Pale Ale, and That's What She Said Stout (chocolate).

You can follow my experiment at my blog if you want to play along. Happy for comments or suggestions as well. As for scientific data, of course, I am not a lab and can already see some flaws in my experiment. Still - it should be at least another data point, even if it is only relevant to how I conducted the experiment. That said - I still want a reliable baseline to work from - and I believe that always using MrMalty, BeerSmith or other provides that baseline for some people. I happen to want to emulate pitching rates at commercial breweries because I believe (possibly mistaken) that they pitch at higher rates, have more consistency than most homebrewers in their pipeline processes, and can replicate their process consistently. Seems like a good goal for a homebrewer.

Let me add - I don't want to fuel a fight over rehydration of dry yeast or liquid vs. dry yeast... that has been hashed over and over. Let's agree that healthy yeast at the right pitching rate is great insurance against off flavors and stuck fermentation and gives the beer the best chance to be great.

 

[bethebrew]

I am going to try a side by side big beer comparison of pitching old dry outdated US-05 in one carboy, and rehydrated outdated US-05 in the other carboy.

First, I have to worry about just how many poor yeast cells have died in the packs in my fridge for the last two years. Worry, worry.

If 50% of the yeast cells have truly been dying by me pitching directly into big sugary wort, then I have some swampland in Florida to sell you.

But like I say, willing to run the test. It's gonna be 1 pack each, into the biggest baddest stout I can whip up.

 

[mchrispen]

Recently I did an IPA that was 1.070 starting gravity. Ended up with two carboys each having a little over 5 gallons. Pitched one old outdated pack of S-04 each and fermented at 62-64F as measured between the two carboys near top of liquid. Fermentation took off after about 24 hours and was vigorous enough to bring some foam up full sized blowoff tube and into the sanitizer in a mason jar.

It's a super vigorous yeast, that finishes fast when fermented at desirable low 60s.

Bethebrew - looks like you already did that, although I do love a stout. I am not here to argue about pitching dry versus rehydrated, rather try to figure out why there is such a strong disagreement between the calcs that people like to use and the manufacturers recommendations. It is confusing for a beginning brewer (if they bother to check) and the common response around here is a recommended a MrMalty or YeastCalc visit (granted normally for starters with liquid yeast).

The convenience and simplicity of pitching 1 pack for a 5 gallon batch is very appealing. However, if MrMalty claims 20 billion cells per gram dry yeast density, and the manufacturer claims 5 billion cells per gram, that is a massive differential between the two in a 11 gram sachet (220 billion cells versus 55 billion cells). My little experiment is to see how different the yeast flavors are expressed via pitch rate - and when trying to document the correct rate for such a small batch, I noticed the discrepancy. Yes I am a bit OCD about these things, and also believe it is the manufacturer's responsibility to provide accurate numbers.

I have also pitched old dry yeast into a fermenter and had excellent results. Never underestimate the resilience and excellent quality of dry packaged yeast. For the record - I didn't hear tiny yeast voices screaming in agony when I did so. There were bubbles so maybe they drowned or just got really gassy.