Monday 30 June 2014

Collaboration Home-brewing. Yes, it is a thing. Part 2

This is the second post about some of the collaboration home-brewing we've been doing with fellow home-brewers. We started this post back in March after publishing Part 1, but due to additional time commitments with work (Chris is now brewing one day a week with Weird Beard Brew Co) and volunteering (Emma has been tutoring an A Biology student), we've struggled to find time for blogging.

Part 2

Our second collaboration arose from a piece of brewing equipment we bought. Tired of constantly swirling a 2L conical flask every time we looked at it, we decided to invest in a stir plate. If you're serious about ensuring you're pitching the right amount of yeast, one of these little toys is a good buy. However, we love having scientific kit in the brewery (kitchen) so that made it an easy decision. When our friend, Andrew Drinkwater, heard we'd bought a stir plate, he pitched a hard-to-resist idea to us. Why not brew an all Brettanomyces IPA and use the stir plate to grow enough yeast cells for a 100% Brett beer?

Where do you start with an all Brett IPA? What flavour profile do you aim for? Which strain of Brett do you use? We threw around some ideas between ourselves initially and, then when we bumped into him at IndyManBeerCon, we asked Thornbridge's ever-helpful Dominic Driscoll for advice. We particularly wanted help with which strain to use and how to make a decent starter for it. Dom consulted some of his fellow professional brewers (Ryan Witter of Siren Brewing deserves a credit here) and came back with an answer for us - use Brettanomyces clausenii (we used White Labs WLP645) in normal sized starter running on a stir plate for about 36 hours.
Our Brett starter on the stir plate.

So with that vital information on how to build up the yeast count answered, we ploughed into phase 2 of recipe formulation. We knew we wanted a very hoppy beer to jostle a little with the inevitable Brett aroma. Doing a bit of research, especially focusing on a presentation by Crooked Stave's Chad Yakobson's on the effect of lactic acid in brewing with Brettanomyces (Chad's presentation to the American Homebrewers Association can be found here) and the formation of ethyl lactate, which produces a pineapple aroma in beer. Coupled with this, we decided to go for a hop bill that would complement the pineapple aroma so we choose Australian (Vic Secret) and New Zealand (Pacific Jade, Southern Cross, Wakatu, Motueka and Kohatu) hops. We stuck with a fairly basic grain bill of Maris Otter, malted wheat, Pilsner malt, acidulated malt (for the lactic acid) and Carapils. We aimed to mash for a medium body to give it enough punch but without it being too sweet.

The day before brew day, we took stock: yeast starter heading towards high krausen, hops all accounted for, malt... Whoops, we had forgotten to order the acidulated malt. After a short collaborative panic, our co-brewer Andrew offered to drive down to the Home Brew Shop in Aldershot to collect some on his way to stay at his parents' house in Gloucestershire for the night. Phew, disaster averted.

We got everything set up on Sunday morning in readiness for Andrew's arrival. Bacon defrosted for sustenance, cheese plus a good selection of beers in the fridge for later. Then we got an unexpected message from Andrew. He had just reached Clapham Junction only to find that the acidulated malt wasn't in his bag. Where could it be? PANIC! CONFUSION! DISASTER! It transpired that his mum had tidied the acidulated malt away with his other grains which he stores at his parents' house.

While Andrew made the rest of his journey on to our place, we desperately scoured the internet. Could we get any acidulated malt on a Sunday? No, was the apparent answer. Could we acidify some pale malt? Maybe. Could we buy some straight lactic acid? Not easily and it might involve a journey into an obscure part of London. What else contains lactic acid which is perfectly safe for consumption? Emma's previous life working as a lab tech in yogurt manufacturing made her pause for a moment... yogurt? But you can't put yogurt into a beer....and the bulb over her head flickered and died. Just like our brewday by the looks of things.

Andrew arrived and we got stuck into our staple brewers' breakfast of bacon + cheese + some form of bread. This fired the synapses in Emma's brain and the light bulb flickered back into life. The answer to our lactic acid problem was Yakult. For those who've never heard of it before, it's a 'health food drink' that's made with sugar, Lactobacillus spp. and a few other odds and ends (mostly proteins) but the main point is the Lactobacillus eats the sugar and turns it into lactic acid. We looked up the data sheet for Yakult on the interwebs and estimated the volume we might need from the approximate amount of lactic acid they stated was in each bottle. A quick trip to Sainsburys and we were sorted.

With the brewing liquor now on to heat, grains measured out we were finally ready to start. The Yakult went into the mash with the grains because although there are many different ways to make sour beers, in this case (to get the flavour profile we wanted) the acidic pH had to be established during the mash. After we added what we thought we needed, we tested the pH and in the end we had to add more to get the pH down to our target of 4.7.

The rest of the brewday proceeded as planned and we got the wort into the FV in good time with the yeast pitched. We had a little bit of a heart in mouth moment the next day when we realised that after 24 hours there wasn't any activity in the airlock but with a 1degC raise in the temperature using the Chamber of Fermentation, it was soon bubbling away happily. (Note: Chad Yakobson's presentation does mention that Brett strains typically have a 24 lag period, so I guess we should have read it more thoroughly!)

We dry-hopped with Moteuka and Vic Secret and dry-zested it with lemon zest soaked in a small amount vodka to sanitise it, which we pitched also as it had clearly dissolved some of the oils from the lemon zest. We cold crashed the beer to drop the dry-hops out and then kegged the beer before force-carbonating it to 2.7 volumes of CO2 to help lift the aroma and make it zesty and refreshing.

The beer came out really well in the end and we named it 'Sabotage B.A.Y' after the unintentional sabotage by Andrew's mum, that nearly scuppered our whole brew day, and B.A.Y which stands for for Brettanomyces And Yakult. Then we brewed it again, this time with actual acidulated malt and more dry-hops, which came out much better, but this beer only came about because Andrew had convinced us to give the idea a go in the first place.

After the success of the Sabotage B.A.Y, we decided with Andrew that we should try to make another hoppy Brett IPA but this time with US hops instead of NZ/Australian hops. We also decided to change the yeast strain and after a bit of research, we opted for Brettanomyces Bruxellensis Trois (White Labs WLP644) which is a more traditional Belgian strain that produces a slight tartness along with flavours of mango and pineapple. We used the same grain bill as Sabotage B.A.Y but this time hopped with Magnum (bittering), Centennial, Cascade and Amarillo. We dry-hopped with Amarillo and Cascade pellets along with a dry zesting of orange zest soaked in vodka.

This beer came out really well, with a more subtle Brett character than the Sabotage B.A.Y and strong orange and mango flavours. After struggling to name this beer, we settled on 'Helius' after the Greek god of the Sun, which we felt was appropriate with the refreshing orange aroma and flavour blasting out of it. Definitely a beer to brew again.

Probably one thing left to mention that some people are likely to ask questions about - contamination. We used Brett yeast strains in two beers - how did we clean our kit? Well, firstly, anything that the Brett encountered in large quantities (FV, carboy, keg) was labelled with a big piece of Duck Tape with 'Brett' written on it. This way we knew what had to be cleaned using more rigorous methods. Secondly, Brett can be killed like any other organism - heat (steam, boiling water) or sterilisation (various sanitisers) both work pretty well. We opted for the latter in this case with Emma obtaining some Virkon (an oxidiser) that kills almost all microorganisms it comes into contact with. We filled the vessels up with the correct dilution and let the Virkon do its work for at least 30 minutes before rinsing off. We also had a mini-cornie (9L) with Virkon in it for use in cleaning our counter-pressure bottler or dispense line if we've let any of our Brett beers sit in them for a period. As of yet (touch wood), we've not had any problems with Brett contamination in any of our other beers.

No comments: