From Vol. 4, No. 3, July 2020
During the fourteenth century, Emperor Charles IV made exporting hop cuttings from Bohemian plants punishable by death. Farmers understood that not all varieties were alike and already knew how to divide the underground stems to propagate more plants. The variety the emperor sought to protect was likely an ancestor of Saaz, but probably not identical.
A massive fire in the town of Žatek in 1768 destroyed historic documents that might provide more information about early cultivation, which apparently began in the first millennium. Few references to Bohemian hops exist before the fourteenth century, but from the time Charles IV actively promoted the product it flourished. In 1553, the Bohemian town of Plattau became the first outside of Spalt to receive its own hop seal, issued because dishonest merchants packaged inferior hops and sold them as “genuine Saaz.”
Karel Osvald, who began the Czech hop program in 1925 feared attempts to increase yield by hybridization would result in loss of aroma quality, and instead relied on clonal selections of original landrace hops. He made it clear the plants would have evolved over hundreds of years.
“Current hop cultures are a mix of vegetative posterity of various genetic origins. Issue of varieties is absolutely unclear, and we can talk neither of Czech old-Saaz red-bine hops nor of Semš hops. Semš hops originate from old-Auscha hops, which come from old-Saaz hops. Today the cultures of hops are thoroughly mixed, even though there are no great differences between neighboring plants in a hop yard. Hops are plants that can adapt to growing conditions, since the soil and the climate lend them a certain character.”
The Basics: 3-6% alpha acids, 4.5-8% beta acids, .4-1 ml/100g total oil. Many brewers think a lower level of cohumulone (23-26%) results in “smoother” bitterness. Other research suggests that an alpha/beta ratio of less than 1 (many hybrid American varieties have a ratio closer to 3:1) is responsible.
Aroma qualities: “Fine,” whatever that means to you, is often mentioned first. Often described as herbal, but look for the subtle character that lingers, often retronasal: citrus (lemon zest), cedarwood, spicy.
Noteworthy: The Czech Hop Research Institute has released multiple interesting varieties, but Czech growers devote more than 85% of acres to Saaz. That’s where the demand is.