The 2 week brew
A handy, repeatable method for producing a crisp clean Berliner Weisse
It's been a fantastic Summer so far and the Cricket World Cup is starting in a couple of weeks. Perfect conditions for an easy-drinking, refreshing fruit-beer.
Most of this method is based on this presentation by Jess Caudill – Wyeast Laboratories Inc. and Jason Kahler – Solera Brewery.
Step 1 - Lacto Starter - 5 - 7 days
You'll need a starter for the first 'fermentation' with Lactobacillis. (This is not a yeast but it does produce a small amount of alcohol). Pitch a smack pack of Wyeast 5335 in to a 1L starter at 1.020. This will use roughly 50g of DME. Leave for 5 to 7 days in a warm area. Do not aerate the starter!!
If you want to make a second batch, save some of the Lacto slurry from the first fermenter and use this instead of a starter.
Step 2 -Brew Day
Brew 23L of wort, roughly 1.024 SG, with 60% Pilsner Malt and 40% Malted Wheat. You can mash-hop or add hops to a 15 minute boil and you should aim for about 5 IBU. Cool the wort to 30'C and pitch the Lacto starter in
Step 3 - Lacto 'Fermentation' - 3 - 4 days
Here's where a pH meter would be handy. You should aim for a reading of about 3.3 pH which should take 3 or 4 days. You can use taste as a guide. There will be airlock activity and a krausen will form and dissipate.
Step 4 - Saccharomyces Fermentation - 3 - 4 days
Here's where it gets interesting. I've racked to another fermenter and added 450g of DME (what was left over after I used 50g in the Lacto starter). Then I've pitched brewer's yeast - Wyeast 2124 and 1007 or White Labs WLP036 would be the most acid-resistant choices but I'll be using US-05 next time.This will be a very quick ferment and it should finish very dry.
And add some fruit. Lots of fruit. I can personally recommend 100g per L of thawed blackberries, or a similar amount of stewed rhubarb.
Step 5 - Packaging
I prefer kegging for this beer as it's made for quick drinking and filtering into bottles is too fiddly - there's a lot of fruit in there. My normal process is a 48 hour crash chill and syphon directly into a keg. This beer does not get better with age so no problem with force-carbonating.
Alternate Endings -
For a bit of complexity, rack off the fruit and pitch some Brett in to the fermenter when the second fermentation has stopped. You'll need to taste frequently but about 6 to 8 weeks should be enough time for the Brett to develop. If you don't feel like splashing out $22 for a Brett culture, buy a bottle of Lambic and tip in the dregs. Warning - Brett has a habit of contaminating a brewery. If you use it, please set aside some equipment specifically for testing / tasting / bottling / kegging sour beers.
I've split batches after the Lacto phase to try different fruit combinations - rhubarb and Black Doris Plum with Brett is my current favourite.