Stepping up Pacman?

[Ultima]

I harvested some Pacman yeast from a bottle of Rogue Shakespeare Stout, just dumped the dregs into a growler that had 1 cup DME and 4 cups water boiled etc. It grew up pretty nicely, I think, there was a nice yeasty layer on the bottom of the growler after a couple days at room temperature. I put the growler in the fridge another couple of days ago, and I won't be able to brew until midweek or so, so I was wondering if I should add some more starter to the jug, or just keep the yeast in the fridge until brew day?

I also have NO idea what kind of beer I want to make with it, so any input on that front is appreciated too. Thanks!

 

[SickTransitMundus]

Definitely step it up. Pour the fluid off, add more boiled DME/water and let it chew that up. Then chill overnight and repeat. Ideally you want to get about a cup of yeast slurry from the starter - maybe a 1/3-1/2 inch layer on the bottom of a standard growler. Usually you need more than two iterations to get a healthy starter from dregs.

Your DME/water ratio should be 1 gram DME per 10 mL water.

Pacman is good for just about any American ale style, especially pale ales and IPAs. It has a neutral flavor profile with a nice minerally finish, so it really brings out hop flavors. If you have temp control, I recommend fermenting it cold - 58-60F is optimal.

 

[pfooti]

Also worth noting that Rebel Brewer gets pacman in stock every month or so. I bought four packs a while back and brewed a LOT of different styles with them (reusing from washed cake). I'm happy with a lot of the features; it ferments cold and very neutral, attenuates really well (it especially eats a lot of stuff from crystal malt additions that calale leaves) and drops out like a bomb.

For me, it is that last bit that made me decide to go back to calale for my neutral yeast. I had some pretty significant bottle conditioning problems with pacman, had really uneven carbonation in some batches, really slow carbonation in others. My theory is that even after about three weeks of fermentation (sometimes racked to a secondary, sometimes not), there wasn't enough yeast left in suspension to carbonate properly. That, or I got a bum batch of corn sugar, because the rest of my process was pretty much the same, and the carbing problems really only arose when I started using pacman.

My last couple batches, I threw in a few grams of rehydrated US05 or US04 (depending on what I had laying around) with the priming sugar and have had no problem with the carbonating, which further supports my hypothesis.

So, good luck with the pacman stuff. It's definitely great for beers with a lot of crystal malt in the grain bill, and it is always fun to have a fancy special yeast. If you're bottle conditioning, though, consider doing what I did or else plan on waiting 6 weeks for the bottles to really carb up.

 

[SickTransitMundus]

I had some pretty significant bottle conditioning problems with pacman, had really uneven carbonation in some batches, really slow carbonation in others. My theory is that even after about three weeks of fermentation (sometimes racked to a secondary, sometimes not), there wasn't enough yeast left in suspension to carbonate properly. That, or I got a bum batch of corn sugar, because the rest of my process was pretty much the same, and the carbing problems really only arose when I started using pacman.

Yeah, pacman is uber-flocculant - more so than cali. I keg and force-carb exclusively, so I hadn't run across bottle conditioning problems. Combined with whirlfloc this stuff makes a spectacularly clear brew.

I buy pacman smack packs whenever they're available and hoard them. I use a lot of it. I think I've got about five in my fridge at the moment. Every so often I make a big starter and split the slurry into sterile canning jars.

I've had trouble repitching onto it, though - good attenuation but some off-flavors. I stopped reusing yeast cakes a while ago - not just for pacman but everything - and the problem went away.

 

[pfooti]

I've had trouble repitching onto it, though - good attenuation but some off-flavors. I stopped reusing yeast cakes a while ago - not just for pacman but everything - and the problem went away.

Kind of off-topic but yeah, there's definitely a difference between reusing yeast and repitching onto an existing cake. Usually when you pitch onto an extant yeast cake you're really overpitching and you're adding a fair bit of extra trub and crud into the brew. I will harvest yeast from an older batch, rinse it, and repitch part of it into the next generation of brew. Saves a lot of money on yeast; a proper pitch into a moderately-sized beer (1.065) would usually be two smack packs or vials per five gallons. Even starters start to get pricy when you calculate how much you're spending on DME (not as much as more vials, of course, but still).

Back to the OP: I would suggest your first brew be a moderate-strength American Pale Ale or American IPA with a fair amount of crystal malt. Like I said, pacman loves crystal malt (and so does Rogue, they have up to 20% crystal in a lot of their brews, which is why pacman is the way it is). Yooper's Dogfish Head 60 clone with 12-16 oz of crystal 40 or 60 thrown in is roughly the house IPA I've been fiddling with for a while now.

I would also suggest you try and get an estimate of how much yeast you have in your growler and use Mr. Malty to figure out how much you need. Use the repitching from slurry calculation, but if you just measure the stuff at the bottom of the growler you can increase the yeast concentration slider up to 3.5 or 4.0 billion/ml.

One good way to estimate how much yeast material is in your growler is to take a second, identical growler, and add 10 mL at a time to it until you get it filled to the same level that the yeast are at in the fridge.

If it turns out you need more yeast than you already have, what you can do is this: figure out how many billion cells you have right now (volume * density) and set that as the viability percentage of a "vial" on the vial of liquid yeast tab on Mr. Malty. So if you've got about 180 billion cells, but need 250 billion (because you're doing 5.5 gallons of 1.065 beer), you tell mr malty that you have 1 vial of 180% viable yeast, and it tells you that you need to put that vial into 1.43L of a simple starter or 1L of stir-plate starter.

 

[weirdboy]

I wouldn't think that all the yeast in the cake at the bottom of the growler is 100% viable. Nor is it even 100% yeast.

 

[pfooti]

No, but that's why you adjust the "non-yeast percentage" (although I typically leave that alone if I don't have a good reason to make it high or low) and the "harvested on" date to get viability. Viability * (1-nonyeast) * density * volume is as good of an estimate of yeast cell count as you're going to get without a hemocytometer and a microscope.

 

[Ultima]

Thank you all for the information. I am also kegging/force-carbing so the high flocculation is desirable. What I'm not sure of is how to estimate the density of the yeast slurry, and how much of it may or may not be yeast. My theory with pitch rates is "just make sure it's enough" and I have never fussed too much over cell counts, nor brewed a beer that wasn't great. My LHBS moves a good amount of yeast so I am confident in viability, and unless I'm making a 1.100 monster brew or something, I will just pitch a vial or smack pack without a starter even.

I'm thinking about making a porter with this yeast. Nothing too strong or fancy, I just haven't made a porter yet. Thoughts on if I should use amber LME and a couple other grains, or some light LME and a few more grains?

 

[pfooti]

I generally advise people to avoid amber or darker LME in any recipe they're putting together themselves. It's hard to know what's actually in those darker LMEs. Recipe kits from good sources are put together knowing that, but it's probably a lot easier to get consistent and predictable results just using light LME and more steeping grains.

Light with some crystal 40, chocolate malt, and black patent would probably be good, say 24 oz of c40, 12 oz of choc, and 4-8 oz of black patent. Maybe a mixture of light ME with wheat ME for some body/head.