28B Mixed-Fermentation Sour Beer
Wild Sour — Split Fermentation
ABV4.2% OG1.034 FG1.002Grain bill
| Gladfield Pilsner Malt | 2.5 kg | 50% |
| Gladfield Wheat Malt | 2.5 kg | 50% |
Adjuncts
| Yeast nutrient | half tsp @ 10 min |
Yeast
| Matt's Mixed Wild Culture (the 'Other Half' / O/H) | half of Matt's wild culture, pitched into one 12 L fermenter |
| Rua Cultivar (Owen's propagation from Wild Workshop Rua bottle dregs) | Owen's own propagated culture, pitched into one 12 L fermenter |
Water additions
| Calcium Carbonate | half tsp in mash |
| Magnesium Sulphate | 1 tsp in mash |
| Calcium Sulphate | 1 tsp in mash |
| Calcium Chloride | half tsp in mash |
| Lactic acid (88%) | 5 drops in mash + 5 drops in sparge water |
Tasting notes
About This Beer
Owen’s first wild sour, a joint project with Matt. One wort, no hops, split 50/50 across two fermenters, each taking a different wild culture so the two could be compared with every other variable held constant.
- Other Half: half of Matt’s mixed wild culture, split between the two brewers.
- Rua Cultivar: Owen’s own, propagated from Wild Workshop Rua bottle dregs.
A classic Berliner Weisse template, half Pilsner and half wheat. No hops at all, which is the defining choice: iso-alpha acids inhibit lactic acid bacteria, and here the cultures carry all the character.
Brew day
Brewed 17 February 2026. Mash pH came in at 6.0, a touch high, but less critical for a wild sour where post-fermentation acidity is the goal. Sixty minute boil, yeast nutrient at 10 minutes, nothing else.
Split 12 litres into each fermenter, both pitched around 23°C, then into a cool room.
Two cultures, one wort
Both attenuated rapidly to 1.005 by day 4. The pH split is the more interesting reading:
| Other Half | Rua | |
|---|---|---|
| Day 4 | pH 3.4 | pH 3.6 |
| Day 84 | SG 1.002, pH 3.1 | — |
| Day 116 | SG 1.001, pH 3.1 | SG 1.003, pH 3.4 |
Matt’s culture is more aggressive on early acid production, and it held that pattern the whole way, pushing further on both attenuation and acid. Rua may have more Brett character coming through over a longer age.
Both kept drying out and acidifying, and both threw good pellicles, which is the sign of healthy Brettanomyces activity.
Where it went
At about four months both halves tasted clean and fruity with a sharp but restrained sourness, nowhere near biting a lemon, in line with the pH. No off-flavours, and the two were judged similar enough to blend rather than package separately.
Combined into the Other Half fermenter with a 1 L medium-DME charge added to throw CO₂ and purge the oxygen picked up in the transfer. That 22 litres became the souring engine for Owen’s 57L Flanders Red barrel: 19 L into the barrel on 21 June 2026, the balance held as reserve.
Cost
$24.50 all up, about $1.02 a litre, and comfortably the cheapest batch either brewer has recorded. No hop bill, no commercial yeast, and a two-malt grain bill.
Lineage
- Berliner Weisse, kettle sour (January 2026): the previous sour, by kettle technique rather than wild fermentation
- This brew: true wild fermentation, split across two cultures
- Flanders Red 57L Barrel (June 2026): where the combined sour ended up