What this is
2.5 kg of pilsner malt, 2.5 kg of wheat malt, 10 g of hops. That is the whole recipe, and its plainness is the design.
This is not a beer so much as a carrier. It exists to be inoculated with a wild or mixed culture, and everything that makes the finished beer interesting comes from what gets pitched into it rather than anything in the grist. Brewing the same neutral wort every time means the culture is the only variable, which is what makes the results comparable.
Why 50/50 and almost no hops
Half wheat is well beyond what a clean beer would take. It is there for protein and dextrin — a mixed culture with Brett and Lactobacillus works for months or years, and it needs something to still be eating after a conventional yeast would have finished.
10 g of Pacific Gem at 60 minutes is an antimicrobial floor, not a flavour. Hop acids inhibit Lactobacillus, so a sour wants just enough bitterness for stability and no more. Owen’s split-fermentation brew left the hops out entirely and worked fine.
A 90-minute boil, longer than the gravity needs, because a pilsner-heavy wort throws DMS and there is no hop character to hide it behind.
Mash at 67°C. Slightly higher than you might expect for a beer meant to finish at 1.002, but the culture will get there regardless and the extra dextrin is what feeds the Brett in the back half.
What has been pitched into it
5 Magics — Paul Fantham’s culture. Matt and Jamie brewed 40 L of identical wort and pitched it onto Paul’s second-generation trub.
House culture — accumulated dregs from multiple sources plus Brett, built up across 2025 and 2026.
Split fermentation — Owen divided a batch between Matt’s mixed culture and his own Rua propagation from Wild Workshop bottle dregs, which makes it the cleanest side-by-side in the series.
Because the wort is identical in each, differences in the finished beers are attributable to the culture and the vessel, not the recipe. That is the entire point.
Related
The Foeder Pale Sour is the same idea at a different scale and with a different purpose — a slightly richer wort with oats, brewed repeatedly to fill a barrel rather than singly to carry a culture.