Thursday, 2 July 2015

Lambic 2.1

After the lambic barrel of 2014 was emptied I decided I wouldn't get involved in the re-filling. This was for a number of reasons, but the most relevant one to this blog is that I already brewed to this formula and used this barrel so I know what to expect from it. Been there, done that, so to speak, without wanting to sound crude. While I'm very happy with the results from that barrel I have always felt it could have had more bite. I don't recall seeing any pH meters on the brew day, but the finished beer only clocked 4.2 on the pH scale a year later. While the beer compares very favourably on the whole, the acid deficiency is clear when commercial examples are compared, which often have a pH of less than 3.5. In Classic Beer Styles 3: Lambic, Jean Xavier Guinard typifies "hard" lambic as having a pH around 3.4 and "soft" as 3.9. (page 36) and the European Union has declared the highest pH to be considered lambic as 3.9. So ignoring geographical origin that beer was not a lambic by other established standards.

I also understand the mashing process a bit better having done a bit more reading and talking to people at Toer de Geuze, so I have refined the procedure somewhat. A couple of things that seem to be missing from a lot of texts is an explanation for the small bit of barley malt that is added to the wheat during gelatinisation. There are conflicting reasons cited for this but some say it's to perform a mash of sorts to help make the gelatinisation of the wheat starches easier. Also there is no need to boil the wheat, it just needs to be kept above its gelatinisation temperature. Anyone who looks at a turbid mash schedule, which is what the genuine lambic breweries in Belgium do will notice that there is no cereal mash and at no point is the wheat boiled. For the reason I've changed some of the steps, simplifying and speeding up the process a bit:

The original quantities gave a water to grain ratio of about 3:1. This is in the regular ale brewing range but from experience I can say that with that much wheat both the mash and sparge are close to sticking point. My new step of adding 3L of boiling water to the gelatinisation pot after the 30 minute gelatinisation rest the "strike" water thins to a ratio of 3.6:1 in the mashtun while also helping to raise the temperature of the pot contents to "strike" temperature. This keeps the mash thin enough not to stick but lots of stirring is still required to aid conversion.

For 20L, revised:

1. Add 2kg wheat + 0.6kg malt to a pot with 15L water and heat to around 62°C
2. Bring to gentle boil for 30 mins
2. NEW: Hold at ~62°C for 30 minutes
3. Let cool to normal strike temp for your gear, plus 3 or 4°C (as you want to mash at 70°C)
3. Add 3L of boiling water to the pot. Apply heat and raise temperature of the pot contents to 3 or 4°C above normal strike temperature (to 80°C in my case).
4. Use as strike water and add to the remaining 2.4kg malt in the mash tun.
5. Hold at 70°C for 2 hours.
6. Sparge with 92°C water until 26L collected.
7. Boil for 2 hours, add 3-7 IBU shitty hops at 120 mins.
8. Collect around 20L in the fermenter.

I have done this procedure twice now (and lambic 2.0.1 twice), and not being restricted to a barrel has allowed me to experiment with different configurations, especially with regard to yeast. The first two were brewed to the 2.0.1 schedule and have WLP-645 grown up from dregs of a Framboise given to me by Nigel Comerford. As of 18 June 2015 these have fermented out, but have not produced a pellicle, three months in. Both done to the 2.1 schedule were actually done as a double brew, and split into 2 x 20L batches. Both were fermented out with a neutral ale yeast before having dregs added: the first had the dregs from the 2014 lambic barrel added, the second had the dregs from Boon Mariage Parfait. Two months later both smell fantastic, though the Mariage Parfait is edging it. Both are showing signs of pellicle development too.

Since I wrote this I had refined the process even more and will blog about it after my next brew. I'm going to call it 3.0 as it's different enough to warrant it. Stay tuned!


  1. Great post Shane, will you be entering these beers in Sourfest?