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Boon Oude Gueuze dregs: isolating the Brett and Sacch

WB-BUG-2026-023 · banked · started 2025 (year approximate)

Complete

Current state

Banked: the Brett, Boon Gueuze - Brett, used multiple times with great success, and the Saccharomyces, Boon Gueuze - Sacch, not used yet. Written up long after the event: few photos and details survive.

Source

A bottle of Boon Oude Gueuze, Boon (see the tasting note): dry with assertive bitterness and pronounced funk. Given I could get hold of this beer early on during my experiments with yeast, I decided to attempt isolating the bugs.

What else was in the bottle

Only dregs micrographs are available.

Bottle dregs under phase contrast: elongated cylindrical cells singly and in short pairs, a few small round cells, large out-of-focus oval cells and clumps of debris near the edge of the field, 1000x oil immersion Bottle dregs · 1000x oil immersion, phase contrast, not to scale

Bottle dregs under phase contrast: elongated cylindrical and sausage-shaped cells, some with granular contents, a pair of small ovoid cells, a large branched debris particle at the bottom and out-of-focus oval cells, 1000x oil immersion Bottle dregs · 1000x oil immersion, phase contrast, not to scale

Bottle dregs under phase contrast: scattered elongated cylindrical cells, some end to end in pairs, small round cells, fine debris and a few bright clumps, 1000x oil immersion Bottle dregs · 1000x oil immersion, phase contrast, not to scale

Plating and colonies

Colony Round Medium Days Temp (°C) Morphology Notes
Brett not recorded not recorded not recorded not recorded not recorded Kept; banked
Saccharomyces not recorded not recorded not recorded not recorded not recorded Kept; banked

This was long ago, so I don't have many photos or details for the journey.

Microscopy

Placeholder

Micrographs of the Brett and Saccharomyces isolates to be added.

Outcome

  • Boon Gueuze - Brett (WB-BUG-2026-007): used multiple times with great success. One of three Brett strains I have that deliver a distinct character: it accentuates hops, making them come across as hop-funk, exactly the character in the commercial beer.
  • Boon Gueuze - Sacch (WB-BUG-2026-014): never used. If I recall correctly, a mini beer showed it was a POF+ yeast, much like the strains I usually ferment with.

Counts and dates are in the bank inventory.

Log

Date not recorded · Source

Bottle of Boon Oude Gueuze opened and dregs examined under the microscope.

Date not recorded · Banked

Saccharomyces and Brett separated from the dregs and banked.

Date not recorded · Mini-beer (Saccharomyces)

If I recall correctly, a mini beer showed the Saccharomyces was POF+.

2026-11-07 · Write-up

Journey written up from notes. Tasting note and organism pages (previously placeholders) filled in; isolate micrographs to follow.