will one Vile make due

So you think they are making different yeasts for homebrewers and different stuff for commercial?

I'm highly suspect they do this, as it's not a cost effective approach. The packaging is different, so perhaps that could be the issue, but the proofing wort/sugars included in a smack pack don't make it any more or less viable than a commercial bag pitch.

 

Peter,

Since you seem to be an “interested student” I would encourage you to watch the entire Beersmith podcast with Dr. Chris White.

http://beersmith.com/blog/2014/08/11/yeast-with-dr-chris-white-from-white-labs-beersmith-podcast-86/

The discussion of homebrewing yeast product shelf-life starts at 14:00. He mentions that for the vials there is greater than 50% viability at 4 months for the vials. Early indications are that the PurePitch products have greater than 50% viability at the 6-8 month mark.

Cheers!

Jack

 

Same yeast strains but different packaging. You statement of "The packaging is different, so perhaps that could be the issue,..." is spot on.

Wyeast uses different shelf life values for their commercial products vs. homebrew products.

Cheers!

 

Thanks, I am a beersmith podcast listener (though have fallen behind). This likely was the podcast that I listened to earlier. I had brewed my Pale 42 APA and Mocha Brown Ale earlier in the summer and they would have been ready for consumption during the August episode. This could explain why I didn't retain the information when I listened the first time.

 

While that might be their reasoning, I don't buy it.. I think they give homebrew level more "ehh it's okay", simply because they know the silent majority aren't going to be able to tell much difference, or make a starter, or care for their yeast properly. Not only that, but simply because of the lower turn over and it sitting in shops. If they gave it the same deadlines, shops wouldn't carry it often, or enough.

More marketing than actual packaging issues, IMO.

 

More based on science IMO.

You might be interested in watching the Beersmith podcast with Dr. Chris White. He quotes values based upon lab testing at 4 months for the vial and 6-8 months for the PurePitch pack.

Cheers!

 

Of course, he's going to promote his purepitch pack.. it's a new item. Marketing as well, not all science.

My point is- we were discussing the wyeast smack pack, versus the bag/gallon jug type of packaging they have for commercial pitches.

I'd rather take the commercial examples as closer to the claim, as they are the real concerning customer, who relies on the yeast companies to provide accurate info and specs for their business.

 

The packaging of the commercial products and the homebrew products are entirely different.

The commercial products are sold to breweries specifically with the intention for quick use; @honkey will attest to this.

The Wyeast smack-packs are not intended for use within 1-2 weeks; Wyeast lists a 6 month best by timeframe for the smack-pack packaging.

Cheers!

 

I understand that.. but a smack pack isn't anything overal diffrent in material than the wyeast stuff. The wyeast packs for commercial are an opaque white/clear pack, while the homebrew stuff is printed. I understand the differences, I've handled both.

Same yeast, and different packaging, admittedly without the proofing as the pitches for commercial can be pre determined by the buyer/brewery and are usually stepped up in some cases for different use.

Hence why I said, I'd rather assume the commerical notation for use, rather than assume the "marketing" quotation for homebrew use.

You make valid points, and I know I won't change your view on yeast handling, as you take it for whats it's worth from the sources. Just going off my experience and knowing it's a business. Not wanting something to think that commercial is any different from the homebrew level, because it's not.

 

I have pitched Wyeast smack-packs that were a couple/few months old without making starters into low-moderate gravity ales. There were signs of fermentation in less than 24 hours, the fermentation was complete in less than 1 week and there were no off-flavors in the resulting beers (no perceptible aldehydes or VDKs).

I know for a fact that smack-packs are good for timeframes beyond 1-2 weeks.

Cheers!

 

Good and prime aren't the same- thats what I'm getting at. Glad you have good results.

 

I am uncertain what distinguishes good from prime.

If a yeast product can perform a healthy fermentation then it is both good and prime.

Cheers!

 

I want to believe it is science based, but I don't really see anyone support it by saying
(1) we treat our stuff for homebrews by doing such and such, which prolongs the shelf life;
(2) we don't do such and such for commercial pitches because we assume these will be pitched sooner.

If this is approximately right, there is probably some savings passed on to commercial brewers by skipping such and such. But I'd like to know the science, i.e., what is such and such?

 

“(1) we treat our stuff for homebrews by doing such and such, which prolongs the shelf life”

Have you listened to the Dr. Chris White podcast?

He made mention that the PurePitch permits CO2 to escape and he intimates that this is the reason for the longer shelf life of the PurePitch packaging.

“But I'd like to know the science…” Me too! In the Dr. Chris White podcast he made mention of lab testing and the values they measured.

Peter, you are a very smart scientist. Would you be willing to conduct yeast viability studies of homebrewing yeast products? I would be willing to contribute money to this cause (I made the exact same offer to @mattbk in the past). I am sure that other BAs would be willing to contribute as well.

Cheers!

Jack

 

The idea that the yeast manufacturers are doing something to homebrew yeast that make it's vitality/viability loss after several months equivalent to their commercial yeast loss after 2 weeks is preposterous.

 

Flatterer! But who am I to argue?

I haven't done yeast cell counts since a 1992 micro lab in grad school. We actually made a couple beers as part of the lab, an ale and a lager, using can and kilo kits. We looked at the population growth in yeast and background bacteria, changes in sugar, alcohol, and I think dissolved CO2, changes in fermentation temperature profiles, and maybe one or two other things. The premise was we will make beer as an excuse to collect a lot of data, do some statistical analyses, and try to interpret it from a microbiological perspective. Or maybe we were using the data as an excuse to make beer that we would later take on a weekend field trip to sample coastal microbial populations. You could think about it either way. I remember thinking that the homebrew we made was better than anything I had ever made up to that point in time, which I now attribute to the availability of an autoclave to sterilize stuff (I didn't know about Star San back then) and lab grade incubators for temperature control (I never gave temperature control a thought back then).

Anyhow, I do still have a decent microscope that I've been thinking about committing to homebrew related yeast work. It boils down to time and commitment, both of which I think I can handle if I am pursuing a meaningful experiment with sufficiently narrow scope. I suspect that time and not financing for supplies will be the limiting factor, unless you are envisioning an exhaustive study of every yeast on the market (in which case time and financing would be problematic). Beermail with your thoughts on the sort of experiment you are looking for.

 

I will indeed get back to you.

Cheers!

Jack

 

This is just an insurance thing for me, but I do starters on every beer I brew now – high gravity or not. On some high gravity beers I'll even build it up twice over the course of 4-5 days. Like everyone else has said, it's better to have a large colony of healthy, prepared yeast than a colony that struggles to get the job done.

 

“…it's better to have a large colony of healthy, prepared yeast than a colony that struggles to get the job done.” Given the way you specifically framed that statement, I agree.

You might be interested in what Dave Logsdon (owner/brewer of Logsdon Farmhouse Ales) has to say on this topic (or maybe not):

“There is also an upper limit to how much yeast you should add. Logsdon says, “I try to stay within 20 percent of my ideal pitch rate and I prefer to slightly under pitch rather than over pitch. This causes more cell growth, more esters and better yeast health. Over pitching causes other problems with beer flavor, such as a lack of esters.”

Cheers!

 

That is interesting. I'll keep that in mind for the next batch I do. Thanks! I don't think I've ever necessarily 'over-pitched' by a lot for any of my batches.. but I wouldn't say I've done much 'under-pitching' either. Except on an IIPA I did about 4 years back, where I severely under-pitched, and was left with thick, sugary hop sludge I think that's what may have scared me into doing yeast starters for all batches.