Yeast & Fermentation

Is Estrella Damm top- or bottom-fermented? Bottom-fermented, like almost every major Spanish lager. Bottom-fermenting yeast works at low temperatures, settles at the bottom once fermentation finishes, and leaves behind a clear, clean beer. The Alsatian founders knew this technique from home, where it was part of the southern German brewing tradition.

Research has shown that lager yeast is a hybrid of two yeast species. The Dane Emil Christian Hansen isolated the first pure culture of such a yeast in Copenhagen in 1883. Since then, every brewery has been able to keep its strain clean, so a batch brewed in Barcelona today tastes just like the one brewed the day before.

After primary fermentation comes cold conditioning. The beer sits in tanks for weeks while the yeast breaks down byproducts that would otherwise taste of butter or green apple. Exactly how long and at what temperature is something each brewery determines for itself, and no reliable figures are available for the Catalan brands.

Craft breweries work more often with top-fermenting yeasts. These ferment at warmer temperatures, develop fruity esters, and pair well with hop-forward beers. In Barcelona, small stainless steel tanks are used for this, often standing right next to the bar — sometimes visible through a glass panel.

The witbier component in the Estrella Damm Inedit blend ferments top-fermented, like any Belgian-style wheat beer, while the barley malt portion ferments bottom-fermented in the lager tradition. According to the brewery, the two beers are then blended together.