This brew was supposed to be something else entirely. I wanted to brew a Dopplebock for Christmas, so I built a recipe and ordered the grains. Brew day comes along and I’m happy enough, until it comes to taking a post-mash gravity reading. I was targeting 1.065, but it came out at 1.050!! What the hell?! I carried on anyway, and decided to add another 15 mins to the boil – I would have added longer but the first charge of hops had already gone in.
Once chilled and transferred, I took another reading. 1.076 was the goal, 1.055 was the reading. A little bit bemused, I carried on any way and figured I could still make a Munich Dunkel. I went back over the brew day and tried to find a reason for it to have been so low. Things I verified were:
- Iodine test – correctly showing full conversion
- Volume into FV was correct
- Checked for dough balls in the mash – none were present
- Tested with 2 hydrometers and a refractometer
The only thing I could think of was that maybe the crush of the malt was too coarse, leading to very poor efficiency. I asked the wider Homebrew cub members and they couldn’t offer any further advice than what I’d tried, so I sent an email to Malt Miller explaining the situation. AFter sending them a photo of the Munich malt, they confirmed the crush was poor and that they’d send me out a new batch!! Awesome customer service, they sent me out another 6kg of Munich I malt and three packs of Mangrove Jacks dry yeast for me to have another stab.
Where it went wrong, again
After letting it ferment out for over a week, I took a gravity reading at 1.020. Thinking it was still on its way, I ramped the temp up from 11 to 13C to try and get it to finish. Also, after another three days it was still at 1.020. I tasted it and it was really bad, sugary and poor flavour. So I decided I was going to dump it and make something else. That is, until I saw some empty demijohns sitting in the garage that had been there for months unused. And then the idea hit me – how about inoculating with some bugs and seeing if I can make some sours? I’d never done sours or wild fermentation beers before, so I started reading up.
Project Sour
With three clean and sanitised demijohns ready, I racked off a gallon of Dunkel into each. Then I added the dregs of some commercial sour/wild ferm beers into each one:
- Kernel Centennial Foeders
- Boon Kriek
- De Konninck Wild Jo

Given that the dopplebock had been hopped, I wondered if the Kriek would actually do anything, but as this is an experiment, why not try it?
After about 3 days there was definitely some signs of life from the Kernel bugs. Wild Jo was lagging, so I added some dregs for a Dupont in as well. Kriek wasn’t really doing anything yet. After 7 days though, there were signs from all three of them, and nice pellicles started forming. There was also a fair amount of activity in all the air locks.



We’re now up to 21 days. I haven’t tested the gravity to see how far it’s dropped, or how funky it may have got so far. With Brett though, I’ve heard it’s a slow actor so best to give it a few months. I’m hoping that at least one of them will turn out to be a really nice oud bruin!
