Wild Yeast Culture Experiments - Update and Recipes

I have yet to publish notes on several of my sour beer experiments, so I thought I would give one large update on several works-in-progress. Before leaving for NHC, I tasted all of the batches and recorded notes to reference during my presentation and to start planning storage and/or fruit additions.

Though I'm grouping them together, I learned (and am still learning) a great deal from each brew. So far, 2 of 5 batches have been dumped, both of which for the same reason: unpalatable levels of DMS.

DMS can be produced by some wild microorganisms, but I am confident the starchy, corncob-like flavor in these beers was created in the mash tun/kettle. DMS is fairly volatile, but since I did not boil either of these batches, the DMS that formed was not driven off and remained in the finished beer. After boiling half of one of these batches proved effective in removing the off-flavor, I concluded that a full boil is necessary to produce clean beer at the SHPB, especially those with a considerable amount of Pilsner malt.

I specify this necessity is unique to my brewery, as I have read about (and tasted) clean, corncob-free examples of low-gravity, light-colored beers produced without boiling. Perhaps a faster chilling method will make this method a reality for me (I've had my eye on a Blichmann Therminator for awhile!).

Though no-boil Berliner Weisse (and the like) is a definite possibility, I have also come across numerous commercial and homebrew with high levels of DMS. To significantly reduce the risk of DMS in the finished beer, I recommend boiling as normal. Even a small amount of DMS is perceivable (and overwhelming) in this light and simple style. In the re-boiled batch mentioned, color pickup was minimal, and will be even less in a steam-jacket kettle.

Sour Brown

Split batch of oatmeal brown (the other half was served during our wedding).

Brew Date	11/11/12
OG	1.062
Grist	16 lbs Rahr 2-row (61.5%) 3 lbs Briess Victory (11.5%) 2 lbs Flaked Oats (7.7%) 2 lbs C-60L (7.7%) 1.75 lbs Pale Chocolate (6.7%) 1.25 lbs Debittered Black Malt (4.8%)
Hops	35 IBU Apollo (60 min)
Primary Yeast	N/A
Conditioning	Inoculated with 3 shots of American Wild Ale (11/11/12) Pitched 500mL lacto slurry (02/25/13) Pitched dregs from 3F Gold Blend (early June)

Tasting notes:

02/22/13

Very musty, Not much acidity. Drier than the original but not completely attenuated. Needs a lot more time.

04/19/13

Solid pellicle has formed. Aroma is complex, but still has some stinky, blue cheese notes. Very tart, with cherry pie, fruity flavors, and some musty flavors. Thin. Needs another few months.

06/24/13

Chocolatey aroma. Acidity is picking up; a nice level for a sour brown, with still some residual sweetness at the end of the swallow. There is astringency, probably from the significant amount of ‘junk’ in the sample – yeast, trub, pellicle, etc. Maybe a slight alcohol note, but that could be the combo of the acid and the astringency. OK overall, headed in the right direction, will continue to age and see what happens.

No-Boil Berliner Weisse

Split batch of Saison wort – this half was taken off after bringing the wort to boil.

Brew Date	02/24/13
OG	1.056
Grist	15 lbs Castle Pilsner (68.2%) 6 lbs Flaked Wheat (27.3%) 1 lb Aromatic Malt (4.5%)
Hops	None
Primary Yeast	N/A
Conditioning	Lacto Slurry, mixed culture slurry, Madam Rose 2012 dregs (02/24/13)

Tasting notes:

03/06/13

SG = 1.011 (6.0%). Very aromatic. A hint of lemon, but dominated by a nutty aroma (maybe peanut butter? Also similar to the aroma of UCBC’s Winged Nut). Prickling acidity, not as forceful as I’d like but very pleasant. Nutty flavors are also present, some wheat cracker from the wheat. Simple, but extremely enjoyable already. Great candidate for dry-hopping (Amarillo? Chinook?).

06/24/13

Tasting from keg. Keg was chilled for a period of time. In that time, tasting revealed ‘nutty’ flavor as DMS

Nutty aroma/flavor (DMS) still present at similar levels to prior tastings. I don’t believe it will ‘drop out’. It’s a shame – the acidity level is wonderful. Otherwise a very nice beer.

07/15/13
Dumped keg.

Golden Sour 1 – Double Batch

A double batch (10 gal) of low gravity, malt-based wort. No boil initially, one half was boiled after primary fermentation to reduce the (extremely) high levels of DMS. The other half never recovered.

Brew Date	03/24/13
OG	1.043
Grist	9 lbs Castle Pilsner Malt (47.4%) 9 lbs Rahr Pale Malt (47.4%) 1 lbs Flaked Oats (5.3%)
Hops	None (Heated to 170F)
Primary Yeast	A – Lactobacillus (slurry from growler culture), 3711 (after souring) B – Dregs from No-boil Berliner weisse (before re-boil)
Conditioning	A – N/A B – WY3522 (Ardennes), WL644 (Brett Brux Trois) – after sour, boil

Fermentation/Tasting notes:

03/29/13

A: No bubbles in airlock throughout the week. SG = 1.021. White foamy “krausen”. Sample was very cloudy. Very odd aroma, off-putting (corn stalk - DMS?), carries through in the flavor. Fairly tart, but lacks tartness of a Berliner Weisse. Not much to it other than that.

B: Bubbled vigorously in airlock for ~ 2 days. SG = 1.030. More corn stalk in flavor and aroma than A. Not nearly as sour. Aweful.

03/30/13

B: Boiled for 90 minutes (down to 3.1 gal), added whirlfloc tablet at 15 min left, added 1 gal distilled H2O at KO. Left open to cool to 140F, then covered (flies started to swarm).

04/03/13:

A: Added 1 smack pack 3711 (French Saison)

B: Added 1 smack pack 3522 (Belg Ardennes), Brett Brux Trois (WL culture), mixed culture

04/10/13

A: SG = 1.010. Still very cloudy, much more so than B (looks like thin buttermilk). Corncob in the nose, but has diminished and fades more quickly. Still very tart, and now light on the palate, which leaves less slickness to carry the corncob flavor. The corn flavor is still there, but in lesser quantity. Not much else to the flavor. Prickly acidity on the tongue (more acidic than B, I like this level better). No yeast flavors/aromas.

B: SG = 1.012. Cloudy. Tart, thinner (will be nice with carbonation). Corny flavor is yielding to a crackery, bready flavor (graham/saltine?). Acidity is very pleasant, but I believe it would be more so if further attenuated. The carbonation may give this effect. I’m mostly surprised at the lack of yeast character after fermentation. Maybe it was because of the low fermentation temp (ambient ~ 62F), but I assumed the low pH would stress the yeast and cause some sort of flavor compound, good or bad.

06/24/13

A: Developed a thin, translucent pellicle in bucket. Flavors developing but covered up by DMS. Still gross.

B: Formed ¼” thick white, knobby pellicle in carboy. Not much aroma. Acidity is sharp and lemony, but not much else in terms of flavor. Fairly clean, with a tiny hint of DMS left. Great candidate for fruit (especially in the 1/3-full carboy!).

07/14/13: Dumped A

Golden Sour 2

Brew Date	04/07/13
OG	1.060
Grist	9 lbs Rahr Pale Malt (47.4%) 5 lbs Castle Pilsner Malt (26.3%) 5 lbs Weyermann Wheat Malt (26.3%)
Hops	None (85 minute boil to reduce DMS)
Primary Yeast	Lactobacillus (starting at 110F, apple juice/grain starter). Bucket was left in fridge for a few weeks. Developed sharp acidity in 1-2 weeks.
Conditioning	Wild yeast?

Tasting notes:

06/24/13

Developed thin, translucent pellicle (from either wild yeast in bucket or Lacto starter). Caramel apple aroma. Toasty malt flavor with sharp, lingering acidity. Hints of apple in aroma/flavor from lacto starter (made with apple juice).  Otherwise clean. Another great candidate for fruit!

07/14/13

Racked ½ of batch (~2.5 gal) on 6 lbs of whole, pitted apricots and golden apricots from Farmers Market. Fruit was washed with luke-warm water before pitting. Added ~ ¼ cup slurry from Cantillion Iris Brett C1 (from BKYeast) and mixed starter to fruit portion.

I will most likely add fruit to the (currently) plain portion as well. I have some canned raspberry puree, but I am thinking about adding a comparable amount of canned apricot puree from my LHBS to evaluate the differences of fresh fruit vs. canned puree. More updates to come!