I think I have finally found my favorite way to sour quickly, which is with unmilled 2-row. I discovered this after trying all other methods a few times. What’s interesting to me about this is that it’s probably the most risky when it comes to potential off flavors.
According to Milk the Funk, “If unmilled grain is added it is thought that filling the head space of the kettle with CO2 will help decrease off-flavors such as ‘footiness’ from Isovaleric Acid which are produced by aerobic microbes that are naturally present on the grain.” In order to allow Lactobacillus to do it’s thing while discouraging the stinky acid from forming, it needs to be kept very hot—somewhere between 109-115°F.
The first time I did this, I threw the grains in a kettle and kept it at around 90F, which resulted in a 4 day souring process and what I’m sure was mold that grew on top. Somehow it turned out ok, but mold in beer is bad and should be dumped (though I have salvaged bacteria by harvesting and re-growing it up). The second time I followed the steps better by filling the headspace in the jug to the top, purged it before and after transferring with CO2, and I kept it at 112F for 2 days (of course getting the pH to 4.4 first as well to help with head retention later on).
The other half of this is going to get probiotics. I am going to use GoLive probiotics and also keep it at 112F along with the unmilled one. 100F is ok in using probiotics, but I needed to keep it hotter as I am going to sour it at the same time as the grain one. I will be using one probiotic packet, purge everything CO2, and pre-acidify the wort as well to 4.4.
For the yeast after souring, I will be using WLP648 Brettanomyces Bruxellensis Trois Vrai. The reason for using brett is it can handle a lower pH for fermentation (though I’ve been hearing recently that some brewers use ale strains without problems). The other reason for brett is to play with ethyl caprylate. Why and what you ask? I will be using some buckwheat in this, and caprylic acid can be found on this grain. Caprylic acid, combined with brett and ethanol, ethyl caprylate can form, which can be fruity and pineapple.
Lastly, because I can’t help myself, I plan on using prickly pear puree for a secondary into one of them. I’ve always wanted to use commercially bought puree.
This was my moment.
Batch Size: 2.5 Gallons (split)
Est ABV: 5%-ish
Boil Time: 10 Minutes
Full grain profile:
(84.6%) – 2-Row
(11.5%) – Raw Wheat
(3.8%) – Buckwheat
60 Min @ 156F
20 IBUs 50/50 split Rakau and Dr. Rudi @ 10 Minutes
Jug 1: 1 oz 2-row unmilled
Jug 2: 1 packet of GoLive probiotics
Secondary (both jugs):
WLP648 Brettanomyces Bruxellensis Trois Vrai
Brew day 4/27/18
Collected 2 gallons of wort, cooled it down to 115F, and split it into two 1 gallon jugs. One jug got the GoLive and the other unmilled 2-row. Set the temp to 112F on the Inkbird, with a heating pad set to high, and let it go.
4/29/18: The pH on the probiotic one was 3.5, the unmilled one was 3.3. However, fermentation happened on both. The probiotic one was at 1.038, and the 2-row one was 1.046. Lactobacillus can’t ferment anything more than a .004 gravity drop, so something else got into the GoLive one (or was already present in the packet). Brought each one to the high 170sF and added hops for a 10 minute steep. Cooled to the low 80sF and pitched the brett and let it go for two weeks.
5/19/18: Added 0.8 lbs of the prickly pear puree to the unmilled grain sour.
5/26/18: Bottled the GoLive sour.
6/9/18: Kegged the puree sour.