I (and some of my friends) enjoyed the last batch, so I’m having another go at this. Same recipe as last time, but today I remembered to only put the lager and wheat malts in the mash tun for the main mash.
Speaking of which, given the challenge I had last time to control the temperature (a tiny mash, followed by the souring at 50C for 3 days), I’m trying a new (and I think cunning!) approach: I’ve put a grain bag in my smallest fermeting bucket (my original 25 litre one). I then put this inside my HLT, which is a slightly larger diameter plastic bucket with a kettle element in it. The HLT has water in it, and an upside-down pyrex casserole dish on the bottom to prevent the mash busket from making contact with the element. I’ve got the HLT being controlled by one of my temperature controllers, and set at 67C to maintain the mash temp. When I come to the 50C rest for 72 hours I’ll put the whole lot inside one of my fermenting fridges (so it’s not just sitting in my unheated garage), and with luck it should maintain a nice steady temperature for the entire time.
Well, that’s the theory. The practice so far has been that by the time the HLT water bath had reached 67C, the mash itself had dropped to about 58C. So I’ve got the HLT set at 70C for now to bring it back up. I also haven’t decided how I’m going to drop the mash down to 50C – I’ll probably just let it drop on its own.
I’ll also dry-hop this one when I’m done, with something different to last time’s Galaxy. I’ve got quite a variety of hops in the freezer, so I’ll pick one when the time comes.
- Length: 19 litres
- OG: 1.030
The mash went ok in the end – the temp rose back up to 62C, so I’ll probably have a very fermentable wort. I threw a couple of towels over the top to try and keep the temperature stable.
Now the mash is done and the acidulated malt added, the setup is in my fridge, and I’m letting it cool towards 50C. The temp probe is in the mash itself, but when we’re down to 50C and I’ve added the remaining lager malt, I’ll move the probe to the HLT water bath so the clingfilm cover can remain undisturbed and airtight. At that point I’ll also throw the towels back over it to help maintain the temperature.
2016-03-29: Finished its sour mash – smelling pretty bad, to be honest. When I got at it and removed the clingfilm, it was clear that the clingfilm hadn’t covered all of it, and some aerobic bacteria had got hold on the non-filmed bits. They were grey, blotchy, and quite nasty smelling. I skimmed them off and ended up with a lot better (if not nice) smelling wort. I heated up 15 litres of sparge water to 76c in the HLT, then dropped the grain bag into it. I found more grey goo in the bottom of the mash tun, so skimmed that as well, then poured into the grain bag (in the hope that the bag and grains would act as filter for the remaining bits of goo that were too small to skim.
I kept it all in the HLT and brought it up to a boil (I’d forgotten how long it took – my gas burner is quicker!), added the 16g hops (Saaz this time), half a protafloc, and gave it a 15 minute boil. I then (slowly – the immersion chiller was running very slowly for some reason) cooled it to 37C and syphoned it into a FV (syphon as no wort chiller on the HLT). A few bits of hops made it through to the FV, but never mind… Gravity measured at 1.030, and it didn’t taste bad at this stage, so that’s a bonus. Noticably sour, if not as much as last time. Tomorrow morning when it’s down to 18C I’ll pitch the yeast (Nottingham) and add a teaspoon of yeast nutrient for good measure.