A20 Citrus
Liquid Ale yeast from Imperial Yeast.
Lab
Imperial Yeast· Ale · Liquid · A20
Imperial Yeast· Ale · Liquid · A20Specs
Attenuation
73–75%
The share of sugars the yeast ferments out. Higher attenuation means a drier, stronger beer.
Optimal temp
19–27°C
66–81°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
≈10% ABV
The rough ABV ceiling where the yeast stresses out and stops fermenting.
Genetic traits
Phenolics
POF−
Ferments clean
Phenolically clean (POF-negative). No clove or spice, so malt, esters, and hops come through unmasked. The norm for American and British ales and most lagers.
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
Usually used in
Hazy IPAAmerican Pale AleImperial IPARed IPAWhite IPARed AleAmerican Wheat BeerBlack IPARobust PorterAmerican StoutWinter Seasonal BeerAmerican BarleywineImperial StoutAmerican Strong Ale+2 more
Common questions
- What is the A20 Citrus equivalent?
- Cerberus, OYL-200 Tropical IPA, and WLP644 Saccharomyces brux-like Trois — the same strain from other labs, the Trois (Saccharomyces 'brux-like') strain.
- What is A20 Citrus's attenuation?
- 73–75% apparent attenuation.
- What temperature should I ferment A20 Citrus at?
- 19–27°C is the recommended range.
- Is A20 Citrus diastatic (STA-1)?
- Yes. A20 Citrus 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 A20 Citrus good for?
- Hazy IPA, American Pale Ale, Imperial IPA, Red IPA, White IPA, Red Ale, American Wheat Beer, Black IPA, Robust Porter, American Stout, Winter Seasonal Beer, American Barleywine, Imperial Stout, American Strong Ale, Wheatwine, and Cream Ale & Blonde Ale.
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