Yeast Test - Fresh Pitch vs Slurry

BJCP Style: German Pilsner

Something went terribly wrong with a recent double batch I did of Festbier and Märzen. The festbier tastes like a saison. The Märzen is better but that saison-y character is still hiding in the background. It might lager out. It might not.

What happened? Last year (2018) for Oktoberfest I brewed about 6 different beers from a single packet of SafLager W34/70. I started with a Helles, split that slurry for Festbier and Märzen, then went on to make some other lagers for our annual Oktoberfest party. Everything came out great. Because of timing, trips, and brew schedule I couldn't go from beer #1 (a German Pils made a few weeks prior) to to the festbier/märzen brewday. I had however saved 1L of yeast slurry in a jar as usual. Thinking that could be stretched for two batches I pitched half into the Festbier and the other half into the Märzen.

And here we are with two lagers that taste like saison. Underpitched? Or did the yeast get infected with Something Wild? At this point I'm leaning towards underpitch, but a wild entry to the game is also possible.

This test is to make sure the repitch method can reliably produce Good Beer provided I use the whole liter. In this case it is a saved slurry from a Dunkel brewed on 7/28.

The Dunkel acted as a control for the bad batches: it was made with a fresh pitch of 34/70 and came out as expected.

2019-10-8: results: I didn't like either of these beers. Maybe I went a little too heavy with the bitterness or the malt/hop combo just wasn't a good match. It was too "dusty?" had somewhat of a wet cement flavor in the background. Next time I think I'll go back to using Weyermann Pils for Pilsner (and probably everything else).  
Having said all that, the fresh pitch was indeed superior in EVERY WAY than the slurry batch. Could it still an underpitching issue? One more test to find out! TL;DR: Yes. It's probably underpitching. The Dortmunder came out not-funky and tastes normal except for the dusty malt flavor.  
The differences between these beers were apparent right away. The slurry batch was obviously darker and slower to clear. The fresh pitch batch had beautiful foam and would easily form a thick meringue when slow poured whereas the slurry batch foam was lackluster and pretty floppy/droopy when slow poured. I could easily pick out the oddball in a triangle as the slurry batch did indeed have a slight funk though not nearly as bad as Frankentoberfest. 

Full recipe is on BrewersFriend but here's the TL;DR
  • Brewday: 2019-8-31
  • Malt: CO Proximity Pale
  • Hops: [Magnum] (Tettnanger)
  • Yeast: SafLager W34/70 - fresh pitch OR slurry
  • OG: 11.6°P (77% efficiency); FG 2°P; ABV 5.1%
  • 2019-9-11 (+11): cold crashed in fridge + added gelatin to both batches
  • 2019-9-16: kegged, burst carb'd @ 40psi for 20hrs
I'm not including all the process shots for this. If you want to see a full brewday process check out the Munich Helles from last year

Mash temp

Bag out - double batch of anything makes for a reeeeally heavy bag

46L of wort to boil. This will end up at 44L and get split into 2 22L batches.

Nutsack. Eating our peaches.

Fresh pitch

Away we go: fresh pitch on the left and slurry on the right.

Post brewday tasties at Call to Arms

2019-9-9 (+9): fermenter samples. Neither one tastes like saison! The slurry (right) is a bit darker but we'll see how they look once clear.

2019-9-12 (+12): Cold crashed with gelatin

2019-9-17 (+17): kegged... in NEW torpedo kegs!

potato quality. happens when trying to take a pic with one hand and hold the auto-siphon with the other...

Labels - carbonating now and will have some foamy pics soon

2019-9-18 (+18): carbonated and initial results are in: not looking good for slurry-side. color is darker, there's less foam and lacing, and I'm picking up some tart fruit off-flavor like the failed Festbier/Märzen batches though not as pronounced. It still has a chance to improve.

2019-9-29 (+29): more samples. Still darker/hazier on the slurry side

Top down

Foam comparison. The foam on the fresh pitch is far superior. Much more retention and lacing and will create a nice meringue if slow poured.

2019-9-28 (+28): slow pour with the fresh pitch side. Nice foamy head