The idea for this came from the Hill Farmstead web page and from the Mad Fermentationist web page’s Neverwhere all brett IPA and later on from the book American Sour Beers, the idea being a IPA fermented only with Brett and in this case WLP644, White Labs Brettanomyces bruxellensis Trois.
Due to the small amount of yeast in the vials supplied by White labs it was a bit of a job to grow the brett up to enough to pitch into 40L of wort and took 5 steps. step 1 was 2 x vials in 0.4L -> 0.8L ->1.5L -> 2.5L ->4L, this was then calculated to be enough for the fermentation, I really need to get using the microscope and counting plate to get more accurate with yeast pitching rates. Below is one of the early steps of the starter.
The recipe is below, Mashed for 60min at a temp of 67degC and mashed out at 74degC, the wort was then transferred to the boiler and boiled for 90min.
|Est Original Gravity: 1.060 SG|
|Est Final Gravity: 1.015 SG|
|Estimated Alcohol by Vol: 5.9 %|
|Bitterness: 72.3 IBUs|
|Est Color: 9.2 EBC|
There is a pile of hops added from 30min to go, with a big addition of hops at flame out for a 30 min steep.
The IPA should take 3 ish weeks to ferment out and then will be dry hopped for 3 days with a big addition of Citra and Centennial (or Galaxy if i can find some pellets).
The idea is that a IPA only fermented with brett will develop a citrus character from the yeast alone and this combined with the citrusy hops will end up being something special!
The main difference between the above recipe and the one in American sour beers is that i have not used Acid malt, the idea behing the acid malt is that the Lactic acid from it will allow the brett to develop more of a citrus fruit character from the production of ethyl lactate, time will tell if this causes a problem or reduces aroma. For further reading on all things to do with brett fermentation have a look at this Brettanomyces Project by Chad Yakobson.
I have had to abandon the beer in the fermenter to come to work so I am hoping on my return it will have fermented out and is ready for dryhoping, updates to follow.