Yeast pitch rate: Single vial vs. Yeast starter | exbeeriment results!

[stratslinger]

Sorry - I was going on your assertions that 1) underpitching was helpful for repitches, and 2) that you don't need a lab to learn the behavior of your yeast.

I guess I disagree less on the second statement than on the first. I'll try to look up the reference tonight, but they were adamant that underpitching is a chief reason that yeast underperforms in subsequent pitches.

As to the lab - yes, you can make observations based on what you see and taste in your finished product - but again, White and Jamil Z consistently reinforce basic lab apparatus for use in measuring cell density in pitches and using that information to determine accurate pitch rates, as well as to monitor the ongoing health of your strains. I agree that such lab use is definitely not necessary - tons of us make good or even great beer without those labs - but authorities way smarter than me insist that it can be a major benefit.

 

[rayfound]

Great discussion guys and gals. Glad you're enjoying the test... and don't forget... split a batch and try for yourselves... and share the results!!

 

[rayfound]

Thanks for doing all that Ray, was a great read.

You put the chamber temperature probe on the Starter carboy... with the different ferment rates and times do you think there might have been a significant difference in ferment temperatures?

I temp Probed the starter beer, but had a fermometer on the vial batch. They tracked very close together.

 

[drumuglyknuckles]

ok ok. but what about pitching old yeast without a starter. example: i buy the discounted yeast from my supplier because it is a month over date and pitch straight into my wort. what then??
i done this a few times and the beer came out ok. in fact, i just hurled a a vial almost a year overdate into a beautiful belgian wort. lets see what comes

 

[kombat]

i buy the discounted yeast from my supplier because it is a month over date and pitch straight into my wort. what then??

You've grossly underpitched your beer, and concordantly, will get all the expected accompanying off-flavours. If you're OK with that (and you seem to be), then more power to you. But the beer would be objectively better with a "correct" pitch rate.

 

[joshesmusica]

You've grossly underpitched your beer, and concordantly, will get all the expected accompanying off-flavours. If you're OK with that (and you seem to be), then more power to you. But the beer would be objectively better with a "correct" pitch rate.

oh don't be so objective... everybody's palates are different aren't they?

 

[kombat]

oh don't be so objective... everybody's palates are different aren't they?

LOL, absolutely! I should have been clearer - I meant "objectively better" in the sense that they'd more closely adhere to the style guidelines. You may like your Czech Pilsners with a prominent green apple flavour, but according to the style guidelines, an example without said green apple will score higher, and is "objectively" better.

Maybe just not subjectively.

 

[stratslinger]

So, a brewing buddy and I recently repeated our much earlier test along very similar lines to what was originally posted - only the expected outcomes should have been magnified pretty significantly because it was done with a lager.

We brewed 10 gallons of Munich Dunkel - everything came from a common mash tun, common brew kettle, etc. Beers were fermented side-by-side in a temperature controlled ferment chamber, after being aerated with pure O2 for 60 seconds (this may have been a key factor to our outcome).

One fermenter was pitched with a Mr Malty recommended starter (I believe it was 2 smack packs in 3L of starter wort, if memory serves), while the other was pitched with a single smack pack. All smack packs had identical manufactured dates (2-3 weeks prior to brewday).

Our tasting process wasn't quite as scientific as the one the original post described - no triangle tests were involved. Instead, we did side-by-side taste tests where we told our tasting panel (roughly 20 people) absolutely nothing about the beers other than the style. Just told them these were beers we made to test a specific hypothesis, and we wanted feedback not colored by any outside info.

Of our tasters, more (4-5) believed we gave them 2 identical beers as expressed a preference for either of the beers (2-3 each way). We had an open discussion about the perceived differences in the beer, which everyone (who could pick them up) agreed were exceedingly minor.

We had one taster fail to follow instructions, and wait to taste until after we explained the difference in the two beers. As you'd probably expect, he was the only person involved (including both of us as brewers) who claimed that the properly-pitched beer was clearly the superior product and the underpitched was clearly flawed - thereby demonstrating exactly why we wanted everyone to taste before having any knowledge of the beers beyond style.

I wanted to believe that the proper-pitched beer would have some advantage. We tried this exact experiment, a few years ago, with a Bock, with almost the same outcome. There was one notable difference that time around that we didn't observe this time: on the bock, the underpitched beer had vastly longer lag time (3+ days, vs >8 hours). This time around, both beers' lag time was nearly identical.

 

[mjcoss]

Great discussion, and love seeing experimental data. Like others, I suspect that it's a complicated process with many factors (temp, strain, etc), and so at the end of the day, I have felt that making a starter doesn't hurt. It demonstrates that the yeast if viable and gives a faster startup of the fermentation process. Is it necessary, maybe not, but to me the real question is does it hurt anything? Assuming you can make a starter with proper sanitation.

Although I have to say that the experiment that I'd like to see is one where you have a series of different pitch rates going from say 1% of what the various calculators say to 100% in steps of 10%. Is there a value at which under pitching causes real harm? or will the yeast carry on with a cell count as low as 1% of the recommended value?

 

[joshesmusica]

Great discussion, and love seeing experimental data. Like others, I suspect that it's a complicated process with many factors (temp, strain, etc), and so at the end of the day, I have felt that making a starter doesn't hurt. It demonstrates that the yeast if viable and gives a faster startup of the fermentation process. Is it necessary, maybe not, but to me the real question is does it hurt anything? Assuming you can make a starter with proper sanitation.

Although I have to say that the experiment that I'd like to see is one where you have a series of different pitch rates going from say 1% of what the various calculators say to 100% in steps of 10%. Is there a value at which under pitching causes real harm? or will the yeast carry on with a cell count as low as 1% of the recommended value?

under-pitching will most certainly cause off-flavors. in the growth phase the yeast throw out all kinds of off-flavors. it's just that:
1) they will typically clean it up after fermentation is complete when there wasn't too many off-flavors thrown out there.
2) the calculators have a very high bar for what under-pitching is
3) they are also typically very skeptical when it comes to how quickly the packaged yeast cells start dying off.

go ahead and do the experiment yourself. create a 1.090 wort. pitch in one vial. report back with the results.

 

[55x11]

under-pitching will most certainly cause off-flavors. in the growth phase the yeast throw out all kinds of off-flavors. it's just that:
1) they will typically clean it up after fermentation is complete when there wasn't too many off-flavors thrown out there.
2) the calculators have a very high bar for what under-pitching is
3) they are also typically very skeptical when it comes to how quickly the packaged yeast cells start dying off.

go ahead and do the experiment yourself. create a 1.090 wort. pitch in one vial. report back with the results.

my take on this experiment - and I am a big fan of brulosophy and read basically all their articles I think - is that it has to do with multiple variables. There are two important lessons:

1. the phase space of parameters that can make good beer is NOT as small as many of us like to believe. - thats a great news. And we sort of all know it. Its not difficult to make a decent or even good to great beer, even if you screw up on a few items and don't quite nail it.

2. You can vary any single parameter (pitch rate, boiling time, mash time, fermentation temperature etc.) by some surprisingly substantial but also somewhat reasonable value, and, provided other parameters are controlled for, the beer will come out great. In fact it will be indistinguishable from the "optimal" parameter beer. Imagine a circle-shaped blob of "ideally tasting beer" in multi-parameter space of all brewing variables. You can tweak any single parameter, and as long as you start at the center of the blob, you can get away with it.

However, if you compound the errors, which means you start way off the center and then walk further away from the center in multiple directions, you will get off "ideal taste" real quick.

Basically, if you are under pitching, your yeast health is bad, your sanitation practices are terrible, your fermentation temperature is too high - esters (or too low - stalling), you can't seem to follow the recipe properly, you bottle too early, or too late, or your transfer technique suck and you still believe in secondary - the errors compound in rather nonlinear fashion and produce a terrible, or at the very least not-so-tasty beer.

so it's a bit like everything else in life. No single tiny event matters much, despite butterfly effect theory, but combine enough little tiny "faux-pas", none of which would matter individually, assuming everything else is perfect, but take a bunch of them together, and you have a disaster of epic proportions.

I also think if you plot distribution of errors among various brewers, they are not random, there is a great deal of correlations. This is 80/20 effect. 80% of beer is consumed by 20% of population (I think in reality it's more like 95% of beer is consumed by 5% of population). Similarly, 80% of brewing errors probably happen to 20% of us.

The brewer who doesn't control his fermentation temperature is also probably the same brewer who is not super-anal about sanitation, or making a starter, or following the recipe precisely. The brewer who is super-anal about fermentation and sanitation is also unlikely to under-pitch 1-year old vial without a starter into a russian imperial stout wort at 120F, or transfer their beer 3 times while splashing it around just for fun, and then not use enough priming sugar.

So you end up with a sort of binomial distribution. Some people get a lot of off-flavors and infections while they tweak a thing here and there and still can't get it right. So they form an opinion that brewing is super-hard.

While most brewers who pay even a little attention to sanitation and follow recipe and good practices, end up with decent to excellent beers, even if they mess a parameter here and there. Brewlosophy is an extreme example of that, showing that if you control ALL parameters and dial them in perfectly, you have a huge margin of error in any other single parameter. But it's probably not a good lesson to most brewers who may be off on a few parameters to begin with and basically need to get everything else perfect, or they are off the "good tasting beer" blob in this 20-dimensional phase space.

 

[stratslinger]

under-pitching will most certainly cause off-flavors. in the growth phase the yeast throw out all kinds of off-flavors. it's just that:

1) they will typically clean it up after fermentation is complete when there wasn't too many off-flavors thrown out there.

2) the calculators have a very high bar for what under-pitching is

3) they are also typically very skeptical when it comes to how quickly the packaged yeast cells start dying off.



go ahead and do the experiment yourself. create a 1.090 wort. pitch in one vial. report back with the results.

See, you seem to be (and I apologize if you're not) overlooking that some of us have done this test (see my post, just 4 or 5 posts back).

Granted, OG wasn't 1.090 in my case - but a 1.070 lager probably should show just as much, if not more, difference when under pitched than a 1.090 ale. And in two attempts running, so far, that just hasn't been the case.

 

[joshesmusica]

See, you seem to be (and I apologize if you're not) overlooking that some of us have done this test (see my post, just 4 or 5 posts back).

Granted, OG wasn't 1.090 in my case - but a 1.070 lager probably should show just as much, if not more, difference when under pitched than a 1.090 ale. And in two attempts running, so far, that just hasn't been the case.

no i read it, but you didn't mention that it was a 1.070 lager. you just said two different types of lager, which i assumed was more around the 1.050-1.055 range. so normal OG size, especially for a single vial or smack pack.

you did mention the bock, but didn't give much detail on that experiment. but for the style a munich dunkel should be between 1.048-1.056, so you can't fault me for not knowing that it was actually like a dubbel dunkel.

i agree that underpitching a 1.070 lager is likely worse than underpitching a 1.090 ale. but i was more responding to you saying to go down to 1% of the suggestion, or however you put it.

either way, i'm going to continue to make a starter, even if it's just a vitality starter, just to make sure my yeast are active and healthy. i want the least amount of lag time possible.

 

[kombat]

Of our tasters, more (4-5) believed we gave them 2 identical beers as expressed a preference for either of the beers (2-3 each way). We had an open discussion about the perceived differences in the beer, which everyone (who could pick them up) agreed were exceedingly minor.

So what's your point? That the research and science documented and explained in "Yeast," and underpinning Chris White's world-class yeast business, is flawed? Because you underpitched one time, and your super-sophisticated panel of BJCP-certified judges could only sorta-kinda tell the difference?

The plural of anecdote is not data. I'm going to trust the guy who has built a multi-million dollar business on his knowledge of yeast, and continue to pitch "proper" yeast rates.

 

[stratslinger]

...i agree that underpitching a 1.070 lager is likely worse than underpitching a 1.090 ale. but i was more responding to you saying to go down to 1% of the suggestion, or however you put it.

either way, i'm going to continue to make a starter, even if it's just a vitality starter, just to make sure my yeast are active and healthy. i want the least amount of lag time possible.

Gotcha.

I definitely would've expected the lager underpitch to be seriously noticeable - both times. And I was shocked that it wasn't.

Like you, it's not going to change my mind about starters - I'm gonna keep using them, but I'll be a little less convinced that I'm doing good rather than doing a ritual...

 

[stratslinger]

So what's your point? That the research and science documented and explained in "Yeast," and underpinning Chris White's world-class yeast business, is flawed? Because you underpitched one time, and your super-sophisticated panel of BJCP-certified judges could only sorta-kinda tell the difference?

The plural of anecdote is not data. I'm going to trust the guy who has built a multi-million dollar business on his knowledge of yeast, and continue to pitch "proper" yeast rates.

All I'm saying is that I've completed basically the same test as what the original poster posted (arguably one that should have magnified any flaws), with basically the same results that he got - and I've done it twice now.

Feel free to draw whatever conclusions you like from that.

 

[kombat]

All I'm saying is that I've completed basically the same test as what the original poster posted (arguably one that should have magnified any flaws), with basically the same results that he got - and I've done it twice now.

Feel free to draw whatever conclusions you like from that.

I'm not discounting your experience, I guess I'm just not willing to risk a batch of beer finding out for myself.

 

[stratslinger]

I'm not discounting your experience, I guess I'm just not willing to risk a batch of beer finding out for myself.

Honestly: neither was I. It was my partner who pitched the single pack, while I pitched the starter (that should have amounted to about 3.5 packs, if memory serves).

I'm still surprised at the outcome, and will need to see several more experiments turn out identically before I can at least say that I'd be happy enough with the results to risk such an underpitch on my own. I mean, between rayfound's exbeeriment and my own two, less formally executed, experiments, I'm willing to say there's enough there to show that there's more info to be gleaned. But I agree, no definitive conclusions can be drawn based on this info alone.

 

[stpug]

I'm not discounting your experience, I guess I'm just not willing to risk a batch of beer finding out for myself.

boooock, bock, bock, bock

 

[brettwasbtd]

boooock, bock, bock, bock

Quadruple bock? Did you use lager and a Belgian strain? Hehe, couldn't resist