yeast pitching rates

[amartin]

Hey All,

For those of you using liquid yeast, how do you decide on a starter size? I used to just make a half gallon starter for a 10 gallon batch and try to time it to pitch at high krausen, and while it would generally work out for me, I'd like a little more control over the process. I built a stir plate a few months ago and have been using this - http://www.brewersfriend.com/yeast-pitc ... alculator/" onclick="window.open(this.href);return false;. However, it has two different stir plate settings, one from Chris White and one from Braukaiser. Any thoughts?

[Keith]

For dry yeasts, unhydrated I sprinkle on 7 grams per 5 gallons. For high abv beers I sprinkle 10grams. Successful everyone. Anyway you can convert?

[mcgster]

Hey All,

For those of you using liquid yeast, how do you decide on a starter size? I used to just make a half gallon starter for a 10 gallon batch and try to time it to pitch at high krausen, and while it would generally work out for me, I'd like a little more control over the process. I built a stir plate a few months ago and have been using this - http://www.brewersfriend.com/yeast-pitc ... alculator/" onclick="window.open(this.href);return false;. However, it has two different stir plate settings, one from Chris White and one from Braukaiser. Any thoughts?

There is a big debate about this, Chris White's formula for calculating growth in a starter was published years ago and it was said to be based off of experimental observation. The braukaiser method came from the blog with the same name that questions the science behind Chris's technique and why the data wasn't published. The braukaiser formula is published on his site with the data, its a small sample set but basic regressions to work out the growth rate.

I'm not sold on either, i like the braukaiser approach of proving it for himself but if you are buying your yeast from White labs it seems funny not to use their formula but trust them that you have X amount of yeast in the package.

[LeafMan66_67]

Hey All,

For those of you using liquid yeast, how do you decide on a starter size? I used to just make a half gallon starter for a 10 gallon batch and try to time it to pitch at high krausen, and while it would generally work out for me, I'd like a little more control over the process. I built a stir plate a few months ago and have been using this - http://www.brewersfriend.com/yeast-pitc ... alculator/" onclick="window.open(this.href);return false;. However, it has two different stir plate settings, one from Chris White and one from Braukaiser. Any thoughts?

I use the Chris White method and haven't had an issue. The one thing I did notice though is when using older or slightly outdated yeast smack packs or vials with this site, sometimes viability is at zero cells starting off, which clearly isn't the case.

[amartin]

Thanks everyone but Keith , although I did pitch my red IPA with US05 (11g/5 gallons, rehydrated), so I am curious to see how that'll turn out. I've been using the Braukaiser one for the last few beers, maybe my best bet is to continue for a while and see how that works out. If I find I'm having problems, I can always bump up my starter sizes.

[McGruff]

The Brewers Friend dry yeast calculator usually says to use way more dry yeast than what I have been using for 30 years. I pitch a sachet for 23 Litres of 1.050 and lower and have had no problems back in the day and none now. I do follow his numbers for liquid yeast and have had no problems, even with lagers.

[GuingesRock]

When I use US-05, I use 4 sachets for a double batch and sprinkle it on the surface of the wort (no stirring), dry. That get's going full pelt fairly quickly, within 12 hours usually, and makes good beer.

[LeafMan66_67]

When I use US-05, I use 4 sachets for a double batch and sprinkle it on the surface of the wort (no stirring), dry. That get's going full pelt fairly quickly, within 12 hours usually, and makes good beer.

For US-05 for me, usually two 11g packs rehydrated for an IPA or other higher gravity beer, one packet rehydrated for 1.050 beer and less.

EDIT: This is for 19L to 20L batches.

[sheppard107]

Any suggestions for sprinkling US-05 or other dry yeasts when you ferment in a carboy. It tends to just land in a little pile in the middle Would re-hydrating be the best route? I'll admit to being lazy/never had a problem dry pitching, so I haven't been re-hydrating to this point. I've never had a problem , but I'd feel better if I had a better way to spread that yeast around.

[amartin]

Any suggestions for sprinkling US-05 or other dry yeasts when you ferment in a carboy. It tends to just land in a little pile in the middle Would re-hydrating be the best route? I'll admit to being lazy/never had a problem dry pitching, so I haven't been re-hydrating to this point. I've never had a problem , but I'd feel better if I had a better way to spread that yeast around.

I'd say rehydrating is your best bet whether in a carboy or bucket, just because you can lose a lot of yeast by not rehydrating it. You paid for the yeast, you may as well get the most out of it.

However, it's important to do it correctly, so make sure to follow the directions either on the packet or on the manufacturers website. I know US05 packets don't tell you much.

[GuingesRock]

Any suggestions for sprinkling US-05 or other dry yeasts when you ferment in a carboy. It tends to just land in a little pile in the middle Would re-hydrating be the best route? I'll admit to being lazy/never had a problem dry pitching, so I haven't been re-hydrating to this point. I've never had a problem , but I'd feel better if I had a better way to spread that yeast around.

I don't think that matters.

more (as in more steps) can sometimes be less , in brewing. More opportunity for things to go wrong and less control/consistency.

[mcgster]

Rehydrating the yeast has been shown time and time again to make a difference in yeast metabolism during the first 24 hours, the question is will it make a noticeable difference on your finished product.

In a blind serving triangle test posted on the Brulosophy site 5 of 13 tasters were able to correctly isolate the beer that was made with rehydrated yeast. Most perceived it as being more malty than the beer made dry pitching the yeast. So in all likelihood rehydrating won't make a huge impact on your end result but 5/13 tasters correctly picking it on a triangle tasting isn't insignificant either. So it really just boils down to personal preference. Rehydrating the yeast takes little to no work so i tend to do it when i use dry yeast but if i forget to i don't lose any sleep over it.

[GuingesRock]

Chris, the key I think is you are not having problems. If you start having problems, that would be the time to re-think/modify your process.

[sheppard107]

more (as in more steps) can sometimes be less , in brewing. More opportunity for things to go wrong and less control/consistency.

That's kind of what I've been thinking. I'm still working on getting consistency of process and results with all the other steps in brewing. Trying to fix something that isn't broken right now probably isn't worth the trouble. But it never hurts to ask for opinions.

[sheppard107]

In a blind serving triangle test posted on the Brulosophy site 5 of 13 tasters were able to correctly isolate the beer that was made with rehydrated yeast.

I'm pretty sure my pallet isn't that refined yet Maybe I'll start worrying about it when I can taste the difference!

[mcgster]

This made me wonder the same thing. I think i'll put it to the test with some of the 2.5 gal carboys i have!

[MitchK]

5 out of 13 is only 38%. Random chance would put it at 33%. That is NOT statistically significant in a triangle test.

[mcgster]

5 out of 13 is only 38%. Random chance would put it at 33%. That is NOT statistically significant in a triangle test.

You can't calculate probability on a triangle test like that, 1 sample is changed, 2 samples are the controls. Correctly isolating the correct sample in a blind serving does not follow simple linear probabilities, instead a chi-square distribution is used. Triangle tests are the industry standard for all sensory tasting, including beer. In fact the Student's T test for statistical significance was invented at the Guiness brewery in 1908.

In a triangle tasting the participant has 3 options:

All three beer are the same
One is different from the other two
All three beer are different

Then, if two beers are the same, which are they?

Finally, describe the difference.


You are describing outcomes for a fixed event, i.e. when you flip a coin you get heads or tails everytime.

[MitchK]

under the brulosophy blog's own one tailed triangle test stats for statistical significance a decent chunk over half the participants must accurately determine which beer is the odd one out.

http://brulosophy.com/2015/09/17/exbeer ... rrections/" onclick="window.open(this.href);return false;

[mcgster]

You said random chance would be at 33%, that is not the case, that is what i was responding to.

[MitchK]

Does the brulosophy site let them pick an option other than choosing an odd one out? Do people go into it knowing one is odd or are they given unbiased freedom to pick your other options? I was under the impression that the former was how that particular test was done.

edit: "Each participant, blind to the nature of the xBmt, was served 1 sample of the pure O2 beer and 2 of the no O2 beer then asked to select the unique sample. " is from their latest experiment. It sounds like testers are told one is the odd one out and if they can't actually figure it out they guess, which would make 33% the random chance amount.

edit2: "In order to achieve statistical significance, at least 11 of the 21 (p<0.05) participants would be required to correctly select the odd beer out. In the end, only 6 tasters (p=0.68) were able to correctly identify the unique sample, which is statistically less than what we would expect by random chance alone, allowing us to conclude that fermenting the same Saison wort under different pressures did not produce beers that were reliably distinguishable."

[mcgster]

In the write up he states that they used the technique in experimental brewing, which is the one i referenced above. I don't have it in text form or i would have just copied and pasted it.

Also i will add that to me, 5 out of 13 correctly identifying the odd beer out in a triangle test is meaningful, assuming they use the experimental brewing technique. Even if it isn't statistically significant at P<0.05. Since the triangle tests as they are performing them violate the assumptions required of the test, mainly there is no control on the testers skills and experience.

[mcgster]

I wish i was in the HRM region, i would love to repeat some of these tests and see if i get the same results. When i go back to brewing on my larger system i'll have two 2.5 gal kegs and carboys which are perfect for testing this type of thing. I'd love to compare mash temps at 148, 150 and 152. Maybe i'll ship some beer out to one of the meetings and have everyone there blind and get them to try the experiment

[MitchK]

I definitely think the brulosophy tests are worth repeating as well, but my main complaint would be sample size... A lot of his tests are done with fewer than 20 people where 5 people being kinda off their game that day (cold, distracted, etc) could have a seriously meaningful effect on the outcome. Not that I think he has some obligation to build an auditorium for these tests, just that they would be more useful if some other like minded people repeated them so that the numbers from multiple iterations could be agglomerated into a more confident conclusion.

[Celiacbrew]

I definitely think the brulosophy tests are worth repeating as well, but my main complaint would be sample size...

His sample sizes wouldn't be an issue if they were homogeneous or if they were the same between tests. His main issue is that he mixes professional, trained and untrained people together and counts them all the same. His statistical test assumes they are all the same.