Mix or underpitch?

[tacks]

I am finishing the boil on my IPA right now, and was planning on pitching 2 packs of US-05, but now that I check my supplies, I have only one packet of US-05 and one of Nottingham. It's it ok to mix these two since I am not going for any particular yeast profile, or should I just pitch one packet of US-05, under pitching?

 

[Hobanon]

Is it a double IPA? Unless your OG is above 1.070, I'd just stick with one packet. I wouldn't want to mix them, typically you only want one strain to ferment your batch. Why not save some wort to make a starter and keep your cooled full volume in a sanitized carboy covered with sanitized foil until your yeast is ready?

 

[fearwig]

Nothing wrong with a mix, especially of complementary (or at least similar) strains like those. If you're going to underpitch I do recommend the US-05 though, as the slightly cleaner yeast (imo). I think you're close enough to proper pitch with dry yeast that it's a judgment call.

Commercial brewers mix strains all the time, though usually to clean up after bad attenuators.

 

[boswell]

If your gravity isn't above 1.070 or 5 gallons, rehydrate either correctly and pitch. I prefer notty as it gets very dry and clear quickly. Take a few minutes and look up the correct rehydration steps, not just any thread. Most just say throw it into warm water, but if you look around you'll find the right way.

 

[fearwig]

Most just say throw it into warm water, but if you look around you'll find the right way.

You could do a little dance, for instance.

Rehydration is fine if you're really worried about 10min of takeoff time, which for some reason people so often are. Otherwise, if you aren't doing a starter, it'll rehydrate itself. In wort.

 

[boswell]

Good one.

 

[tacks]

It ended up at 1.064, I ended up pitching the US-05. Thanks for the help everyone!

 

[mblanks2]

Otherwise, if you aren't doing a starter, it'll rehydrate itself. In wort.

...and kill half your yeast.

 

[fearwig]

...and kill half your yeast.

If you lost half your yeast by pitching dry, most brewers would be pitching at 30% of ideal. Meaning you'd pitch about three dry packs to get it "right". Which no one would ever recommend, because that's bull.

I only pitch starters anyway, but it's silly to say half your dry yeast dies in cool normal-gravity wort but it's magically invigorated by water.

 

[boswell]

It ended up at 1.064, I ended up pitching the US-05. Thanks for the help everyone!

Heck yeah, make beer.

 

[kanzimonson]

If you lost half your yeast by pitching dry, most brewers would be pitching at 30% of ideal. Meaning you'd pitch about three dry packs to get it "right". Which no one would ever recommend, because that's bull.

Yeah, and there's a reason that many new brewers don't make great beer - they follow terrible instructions that are repeated by lazy brewers on this forum.

I only pitch starters anyway, but it's silly to say half your dry yeast dies in cool normal-gravity wort but it's magically invigorated by water.

I'll answer this with the admission that I'm pretty much directly repeating what Jamil has said on multiple shows. Dry yeast are in a vulnerable state in the moments that they're rehydrating. Their cell walls aren't ready to regulate their interaction with their environment. They open up the pathways and let in whatever's around them, but this is before they're able to begin processing the sugars, etc. This overloads the cell and can kill them.

I'm not a biologist, I've never done experiments, but I trust the people giving out this information more than the users on this forum who say, "I direct pitched and it worked fine for me!"

 

[fearwig]

I've heard that (probably from Jamil too), but it contradicts what a lot of other veteran brewers have experienced. I think yeast is heartier than he credits, and you may cause a little undue stress at worst, or who knows 10% lysis even, which would hardly affect your pitch. The effect would be amplified in big beers though, probably diminished in lagers (if cold pitch). I mostly brew smallish ales so I am biased to think about 1.040-1.050ish wort where I don't see it mattering.

I like Jamil and think his focus on fermentation above all else is spot on but sometimes it devolves into nitpicky fiddling over how to open your yeast packet. Sometimes the podcast comes off as a liquid yeast commercial.

Hydration is probably best practice though, don't get me wrong, I only poked fun because there shouldn't be much of a "wrong" way to do it outside of using hot or unsanitary water.

 

[kanzimonson]

If we agree that pitch rate is important, then doing your best to achieve that should be a pretty high priority. So if one of the pitch rate calculators out there tells me I need 8 grams of dry yeast, then I'm going to open an 11 gram packet, throw away 3 grams, and properly hydrate the rest of it.

Pro breweries who use dry yeast rehydrate properly and I feel that as homebrewers we should strive to emulate them as best we can. It's not good enough for me to say "Eh, I'm probably going to kill 10-50% of these yeast so I'll just pitch the whole 11 gram packet."

It's the ol' "if something is worth doing, it's worth doing right" mentality. Especially since on the homebrew scale we really can't get precise enough. Who knows if our starters are actually growing enough yeast, or if our IBU calculations are close to the actual? But if we can at least do things as controlled and repeatable as possible then we're that much closer to perfection.

 

[fearwig]

I think that if everyone stresses and fusses all day long, they might get within 25% of where they ought to be, because I put very little faith in the math and the calculators. Even the best guesses they use are totally wild, based on single cases where trub content and oxygenation and a hundred other factors could be totally different. I still use the calculators to check my work and get a starting point (especially stuff like .75mil*plato*mL and the rough estimates of cell count/mL), but homebrewers often pretend to a level of precision even the commercial breweries probably fall short of.

Now if you don't stress at all... then you are lucky to make drinkable beer. So you need to be cautious and sensible and use those rules of thumb, but if someone thinks they're working with absolutes when they do something like weigh dry yeast from the packet, they're fooling themselves. Starters are as close as you can get to absolute pitch rates because of the natural cell count caps involved, and even then you have to factor in differences in oxygenation, gravity...

 

[kanzimonson]

Agreed for the most part!

I guess my one disagreement is that I wonder if weighing dry yeast isn't more precise than making starters. As you mention, there are so many variables in liquid yeast and making starters, versus the consistencies in producing dry yeast. I'd wager that you can estimate more accurate viability levels with dry yeast than with liquid; therefore you can pretty well correlate weight with active cells.

You mention that there are caps to cell counts and I agree, but I don't think in most starters we get too close to that. Maybe if you made two or three starters of the same volume over and over then you'd approach maximum population.

 

[fearwig]

Yeah, I think the most you can do, and the way commercial brewers seem to do it, when you take away the trappings, is to simply hit your sweet spot based on taste and then keep your procedure as near to identical as possible, forever. It's only science in so much as there is careful measurement to preserve an identical environment. Being truly scientific with yeast is beyond the means and necessities of most brewers. But I still have all these test tubes, so I can pretend.

Dry yeast is probably a pretty solid place to start, I suppose. The main reason I don't do it is because I propagate. No way in a billion years I'm buying yeast for every batch, I make concentrated wort and can it for starters and break a couple out for each new yeast. Maybe fewer variables in dry yeast than cake in tubes, especially since I can't centrifuge out the water. My starters probably aren't that precise either since I shake them, hard to keep your oxygenation consistent when you're relying on intermittent shaking.