Big volume starters: to pitch or not to pitch?

[philbrasil]

Thank you all. About cold crashing, my main concern is that I see a thin whitish yeast layer on the bottom after 12-24 hours. But I see also a turbid/hazy not so compacted layer, which I always attributed to being less floculent yeast. (There is also a clear-beer layer, which I know doesnt have significant amount of yeast). If I dump out this hazy layer before I pitch, will it influence in fermentabilitiy or flocculation?

I am more inclined now to crash-cool for 12-24 hours, decant, and go on from there (either pitch or do another starter)

Oz, I used your topic for a blog post on yeast rinsing (in portuguese): http://noticiascervejeiras.blogspot.com.br/2013/01/introducao-enxague-de-fermento.html

[Ozwald]

Since I don't read Portuguese, I'll just ignore all those dirty things you called me

Regarding your 3 layers, that top layer has more yeast in it than you think. Not all of them are the ones you want to pitch, but they are there. The bottom layer isn't the best either. There you'll find a lot of the early flocc'ers & if you just pitch that layer you'll run into attenuation problems. That turbid layer is made more of the ones you're looking for. If you're able to do the starter a few days earlier, here's a technique you can use. It takes a lot of practice & primo cleaning/sanitation skills but with enough practice & experience you can really dial in your yeast culture. It's yeast selection & very similar to the rinsing technique. In a nutshell, allow the bottom layer to form, rack off of that layer into another vessel, swirl, allow another bottom layer to form, decant. Only experience & practice will teach you when to perform the different steps, but with a little dedication you can transform your culture into super yeast... or do various other things with it. I can get 001 to perform like an English strain or I can get it to push well above the posted attenuation numbers provided by White Labs. If you take it a step further, you can select a very thin layer by doing the separation a couple of times, grow that up in a starter & repeat the process as many times as you want. There's definitely a point where you can go too far - in fact I did a number of times, but it's one of the experiments I did with a few different strains, in fact when I was doing the separations I wasn't dumping but splitting them up, labeling them & seeing how each performed against each other. It's not a necessary step, but it will teach you a ton about your yeast... and you can condition them to do just about anything you want.

Anyways, the main point was to point out those different layers & not to discount that turbid layer, especially early on. If you get good with your yeast selection & conditioning, you'll find that pitching an active starter (along with all that unnecessary starter wort/beer) is completely unnecessary. I treat my starter more like a sourdough bread starter, in the sense that it's always going. I separate out an appropriate pitch up to 5 days in advance & keep it in a foil capped jar in the fridge while I'm still working the main starter. On brew day I pull the jar early in the day & let it warm up to room temp over several hours, occasionally giving it a swirl if/when I think about it. Be careful though, it can turn into an obsession & a part time job after a while. At my peak I had dozens of different cultures going & was spending between 20 & 30 hours a week on them.

[brewindruid]

Yeah, you aren't kidding about the obsession thing, though you are away beyond me.

I have wondered if it wouldn't be possible to use a suction device such as an aquarium vac, or even a siphon tube for that matter, to more effectively pull off starter wort and then more precisely siphon off the desired yeast? The only thing here is that I tend to use percentage of solids to judge cell count, very dicey I know, but really my onllyi option.
I wonder if being that overly selective doesn't result in much more finicky yeast. Something akin to breeding race horses.
Another issue I have pondered is storage time. I am considering stopping a starter cycle short on a light starter and storing in that solution instead of under distilled water, thoughts?

[Ozwald]

Yeah, you aren't kidding about the obsession thing, though you are away beyond me.

I have wondered if it wouldn't be possible to use a suction device such as an aquarium vac, or even a siphon tube for that matter, to more effectively pull off starter wort and then more precisely siphon off the desired yeast? The only thing here is that I tend to use percentage of solids to judge cell count, very dicey I know, but really my onllyi option.
I wonder if being that overly selective doesn't result in much more finicky yeast. Something akin to breeding race horses.
Another issue I have pondered is storage time. I am considering stopping a starter cycle short on a light starter and storing in that solution instead of under distilled water, thoughts?

I've never had a problem decanting. Crash it in the coldest part of the fridge, decant as much as you can, rinse twice (if you're really OCD about getting that little bit of beer off). Even without a rinse or two, you'll have the vast majority of it out. A touch of rinse water after decanting does thin it out & make it easier to pour. Even though I have the lab to do cell counts, I rely on experience for pitching. Get a good feel for the thickness of the slurry vs the volume. It helps if you can do a true cell count against that information (your guesstimations will be much more accurate) but honestly I just aim for a slight overpitch in most of my beers. There's certain ones I purposely underpitch but that has to do with cell stress & the flavors they put out.

Being selective doesn't really make them that finicky in my experience, but it does help to create some very specialized sub-strains that like what they're targeted for over other worts. In my experience with pushing 001 beyond its limits, I didn't really find that I could over select it to the point where it wouldn't perform though, with the exception of the cases where I was pushing it too far on purpose.

As for storage, I always store under sterilized water per my yeast rinsing thread. If I've got a jar that's been sitting in the fridge for excessively long, I'll do a small starter to boost the reserves (I put nutrient in everything), but I don't aim for cell growth. If it's just a week or two, I don't bother. I wouldn't stop the initial starter short, however. Let them finish out, get fat & happy like a bear getting ready to hibernate. Some of the biggest problems I had with any of the yeast work I did was not letting them finish. Think about it, how would you feel if you were almost there & weren't allowed to finish

[brewindruid]

Ah, well said! Everyone wants the happy ending, even those wee yeastie buggers

thanks Lee

Cheers
Scott

[spiderwrangler]

I feel like storing in distilled water is not necessary, and may be detrimental to yeast health over time. They won't burst, as the cell wall will keep them intact, but it does put osmotic stress on the yeast.

[dogismycopilot]

I almost always make starters a week before brew day, chill about 24 hours before pitching, and decant the spent wort immediately before pitching. It's my impression that giving them the time to completely finish their work in the starter (building up reserves when the feast is over, etc) will make them healthier for the job ahead.

I'm sure I could cut a few days off this practice, but with long work days during the week, I really only have time on the weekends.

Also, I do the "intermittent shaking" method. No stir plate.

[Ozwald]

I feel like storing in distilled water is not necessary, and may be detrimental to yeast health over time. They won't burst, as the cell wall will keep them intact, but it does put osmotic stress on the yeast.

Figuring your starter wort should finish fairly low you're talking a difference of maybe 10 points at best. With the results I've gotten, I find the difference at our scale is negligible at best. It's more for longer term storage where leaving it on starter beer could have potential issues, ie darkening, available sugars, etc. It's a tiny difference at best but I've had more issues in extreme tests (stuff you shouldn't do in the first place, but I still wanted to know) with starter beer vs sterilized water. I follow your theory, which makes perfect sense, but it doesn't line up perfectly with what I've experienced under real world conditions/variables.