JY104 was handed to Jasper Akerboom when he toured some small microbreweries in the Netherlands and Belgium by a friendly microbrewer. This strain originally belonged to a small brewery in Flemish Brabant in Belgium. The brewery was acquired by a large macrobrewery, and management decided to do away with this precious yeast. Fortunately passionate homebrewers and beer enthusiasts were able to keep some of the yeast going and you can use it now as well! This strain ferments fast, and aggressive. It can be under pitched easily, and attenuates deep. Great esters and phenols, can be slightly peppery. Flocculates slow, but can withstand spunding without a problem. This yeast is great for lighter colored Belgians, but is great for darker Belgians as well.


This strain has not been fully characterized so we do not know until what gravity this yeast will ferment. We do know that it attenuates very well, and the inital tests have indicated that can ferment easily to 10% ABV.


Origin:                   Flemish Brabant, Belgium
Temperature: 20-25ºC (68-77ºF) 
Attenuation: 75-80%
Oxygenation: Medium
Flocculation: Low

All Major Belgian Styles (Single, Blonde, Dubbel, Tripel, Quadruple, Golden Strong, Witbier, Saison), Belgian-style IPA, Belgian-style Stout

Alcohol tolerance: At least 10%