First Berliner Weisse, pt. 3 - boil and pitch

Gravity when pitching yeast: 1.016

PH when pitching yeast: 2.3

After 24 hours, the wort + sour starter was going nuts. A white pellicle covered the entire top, and lots of CO2 was coming off. The pellicle was there in the morning, but when I went back in the afternoon to take a picture, it was mostly gone, but you can still see a bit on the edges:

After reading a bit more about different Lacto strains, it seems most of them are heterofermentative, even the strains from the yeast labs. My pre-boil gravity was 1.028, and when I checked the wort, it had dropped to 1.016 and the pH was down to 2.3. Lactic acid has pretty much the same gravity as sugar. The gravity drop was most likely due to the lactic acid producing alcohol. It tasted fine, a bit sour, but still pretty sweet. I think once it's done fermenting it'll be pretty puckering.

Here's the bit that I did differently from most Berliner Weisse recipes. Most Berliner Weisses aren't boiled, or are only partially boiled. Since my pH was plenty low, and since I had no idea what other nasty bugs I may have cultured from the grain, I chose to boil a little under half of the wort, and pasteurize the rest.

The half I boiled got the hops, then after a 30min boil, I added the rest of the wort and held between 145-150*F (That's 63-65 for the Centigrade folks) for 30min. The process is called vat pasteurization, and should provide a 3-log kill (99.9%). You can pastuerize faster at higher temperatures, but since my bugs made alcohol too, I didn't want to boil off all the alcohol of an already low-gravity beer.

After I chilled it, I pitched about half of a yeast cake from a batch of Koelsch. This is definitely overpitching in normal circumstances. With the low pH, I was worried about poor yeast performance.

I was quickly running out of daylight last night, so I didn't get a lot of pictures, but here's one of my setup. Bayou Classic KAB-4 burner, 60qt pot, little March pump, and a homemade immersion chiller.

First Berliner Weisse, pt. 2 - Mash and souring

Got the wort into the carboy to start souring tonight. Here's a picture of the setup for the sour starters:

After about 24 hours, the starters smelled strongly of lactic acid (think sauerkraut). They may have had a slight acetic (vinegar) smell, but were otherwise very clean. I was worried about mold/funk/terrible aromas and flavors, but none of that happened. PH for the solutions were 2.9, +/-0.1, indicating Lactobacillus activity. While they tasted sour, they also tasted sweet, so the Lacto didn't eat all the sugars from the starter.

The bug I'm interested in is called L. delbrueckii, which I believe is homofermentative and thermophilic, meaning it likes hot temperatures and just makes lactic acid, not acid and alcohol like some Lactobacillus strains do. By keeping the temp as high as possible, but below 120*, the L. delbrueckii should grow preferentially over other bugs that may have been on the grain.

It turns out I didn't really need any of that headspace, so next time I'll fill them up higher to minimize O2 and the risk of acetobacter.

Here's the recipe I made for this beer:

Batch Size (L): 18.00
Total Grain (Kg): 2.62
Estimated OG: 1.034
Estimated SRM: 2.4
Estimated IBU: 5.4
Brewhouse Efficiency: 75 %
Wort Boil Time: 30 Minutes

Grain
------
68.7% - 1.8kg Rahr Pils Malt
31.3% - 820g of Colorado Malting Company Red Wheat Malt

Hops
------
25g - Willamette (Pellet, 2.0% AA) for 5.4 IBU

Yeast
------
Reused Wyeast 2565 Koelsch

Water Profile
--------------
Profile: RO

Mash Schedule
-------------
Saccharification Rest - 8L infusion, 30 min @ 151* F
No mash out

Sparged with cold water ~ 70* F

Notes
------
Collected more volume than anticipated.

Berliner Weisse isn't a very big beer. The grain bill looks tiny in my 10gal MLT. I chose to mashout with cold water because I was pressed for time and needed to finish up in a hurry.

I ended up collecting more wort than I anticipated. I'll check the preboil gravity and volume after it's done souring to adjust boil time and hop schedule as necessary.

First Berliner Weisse, pt. 1 - Sour starter

The next brew in the works is a Berliner Weisse. This will be my first sour beer so I wanted to start off with something easy. The first step is to make a starter for the Lactobacillus delbrueckii. Pure strains are available from Wyeast and White Labs, but malted base grains are lousy with Lacto (among other things). Since my LHBS is an hour away and doesn't have any bacteria anyway, and it would cost too much to buy a culture online and ship it, I chose the grain route.

Here's the recipe I used:

Into 4L water

Add 400g dextrose

Heat to 110* to dissolve sugar

Divide into 3 growlers

Into each growler goes 1 cup of base malt

One growler got wheat malt, one got pils malt, and one got pale malt. PH of the sugar/water solution was 7.1. I placed the growlers in the shed and wrapped them with a brewbelt heater. Target temperature is 110-120* to maximize Lacto growth.

I wanted to do three separate starters to increase the chance of success. When I harvested wild yeast in the past, half of them took off with good bugs/yeast, and half of them got really rank and nasty. So this way, hopefully at least one will come out alright.

The camera ran out of batteries today, but the next update should have some pics.