B64 Napoleon
Liquid Ale yeast from Imperial Yeast.
Lab
Imperial Yeast· Ale · Liquid · B64
Imperial Yeast· Ale · Liquid · B64Specs
Attenuation
77–83%
The share of sugars the yeast ferments out. Higher attenuation means a drier, stronger beer.
Optimal temp
18–26°C
64–79°F
The range where this strain ferments cleanly, without throwing off-flavors. Most brewers pitch near the low end.
Flocculation
Low
How readily the yeast clumps together and drops clear once fermentation winds down.
Alcohol tolerance
≈12% ABV
The rough ABV ceiling where the yeast stresses out and stops fermenting.
Genetic traits
Phenolics
POF+
Clove & spice
Throws phenolics — the clove and spice notes (4-vinyl-guaiacol) behind hefeweizens, witbiers, and saisons. Expect a spicy character, not a clean one.
Diastatic
STA-1+
Finishes bone-dry
Carries the STA1 (diastaticus) gene, so it keeps eating sugars other yeast leave behind and finishes very dry. It's also a contamination risk: it can over-carbonate or gush if it crosses into other beers.
Same strain, other labs
Potential substitutes for B64 Napoleon
Usually used in
Saison
Standard for these styles
Styles where B64 Napoleon is a standard pick — from the corpus, not the guidelines.
Common questions
- What is the B64 Napoleon equivalent?
- LalBrew Belle Saison, M29 French Saison Yeast, OYL-026 French Saison, WLP545 Belgian Strong Ale Yeast, and 3711 French Saison — the same strain from other labs, the Belle Saison / French Saison (3711) strain.
- What is B64 Napoleon's attenuation?
- 77–83% apparent attenuation.
- What temperature should I ferment B64 Napoleon at?
- 18–26°C is the recommended range.
- Does B64 Napoleon produce phenolics (clove and spice)?
- Yes. B64 Napoleon is POF-positive — it makes 4-vinyl-guaiacol, the clove and spice character of hefeweizens, witbiers, and saisons.
- Is B64 Napoleon diastatic (STA-1)?
- Yes. B64 Napoleon carries the STA1 gene (S. cerevisiae var. diastaticus). It super-attenuates to a dry finish, and can over-carbonate or gush if it cross-contaminates other beers.
- What beer styles is B64 Napoleon good for?
- Saison.
- What can I substitute for B64 Napoleon?
- SafAle BE-134 (same flocculation, similar temperature range), SafAle BE-256 (similar attenuation, similar temperature range), and WLP590 French Saison Ale Yeast (similar attenuation, similar temperature range).
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