POF- Technology gives brewers the opportunity to explore the unique ester profiles of traditionally phenolic strains without the flavor impact of phenolic compounds. Each POF- strain’s distinct flavor profile brings something new to both juicy, hop-forward beers and takes on traditional ales.

POF- Tech

Honestly, we were curious: what happens when you remove phenolics from a Belgian strain?

POF stands for phenolic off flavor, and brewing strains that are POF+ are able to produce the clove-like phenolic compound, 4‑vinylguaiacol, utilizing a gene called FDC1. This FDC1 gene is present in all brewing yeast strains, however most have an inactivated version — those strains are considered to be POF-.

Our POF- Technology uses CRISPR/Cas9 to inactivate the FDC1 gene in POF+ strains, revealing the hidden and unique fruity characters of select phenolic strains, without any of the phenols. Think Hefeweizen without clove or Belgian Dubbel without spice.

How do I use POF– Technology?

Currently there are two strains in our catalog that use POF- Technology: Bananza® Ale (OYL-400) and Sundew® Ale (OYL-401). We’ve seen great success with these strains when used in recipes that aim to really amp up fruity characteristics. During test brewing, the absence of phenolic character allowed both yeast esters and complementary hop fruitiness to come forward in a new way, and was indeed perceived as an increase in the beer’s overall fruit character.

If you are looking to further amplify the fruity profile: experimenting with lower oxygenation rates, higher temperatures, lower pitching rates, and higher gravities beers can boost the ester expression in these strains.


Bananza Ale (OYL-400)
Bananza’s ripe banana flavor boosts tropical character in beer. Bananza is great for dropping more banana notes into your pastry stouts, milkshake IPAs, fruited sours, and other modern tropical fruit-driven styles. View strain info →

Sundew Ale (OYL-401)
Sundew has luscious strawberry and stone fruit esters, which combine to support desirable notes in modern fruity hops. Sundew sets a great foundation for hoppy styles like juicy pale ales, West Coast IPAs or hazy IPAs, or its jammy profile can be paired with more malt forward stouts, milds, and brown ales. Think versatile like West Coast Ale I (OYL-004), but jammier. View strain info →

POF- Technology key points:

  • POF- Technology inactivates the gene in select POF+ strains, giving brewers access to strong ester profiles without phenolic compounds
  • POF- strains reveal unique ester profiles to use in American and British styles

Further reading:

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