Hallertauer Mittelfrueh (Hop) is considered the king of German hop varieties and has a solid reputation as one of the world’s finest aroma hops. Its name derives from the Hallertau in Germany, the world’s largest hop growing region, and from its optimum harvest time in the early middle of the growing season (mittelfrueh means “middle-early”). See hallertau hop region. Because of its exemplary delicate and pleasing aroma qualities, this hop is often referred to by hop marketers as the quintessential “noble” hop. See noble hops. Mittelfrueh is an old “landrace” hop variety. This designation implies that it simply emerged from the land and that its origins are so old that they cannot be documented with any certainty. It also means that clonal variations in the hop exist because of long periods of separate evolution of different plants. In actuality, as is the case with all landraces, such as Saaz, there has probably been plenty of natural cross-breeding with wild male hops. See saaz (hop). Hallertauer Mittelfrueh has a spicy-herbal, complex aroma and produces a smooth bitterness that fits well into the flavor profiles of most lagers, especially pilsners. See lager and pilsner. The hop may take on some cedar, leather, and tobacco notes as it ages. Its alpha acid content ranges from 3% to 5.5%, its beta acid content from 3% to 5.0%, and its cohumulone content from 18% to 28%. Its total oil content is 0.7% to 1.3%.

Although an indigenous hop of the Hallertau, Mittelfrueh is also grown in the Tettnang and Spalt regions of Germany, where they are referred to as Tettnanger Hallertau and Spalter Hallertau, as opposed to Hallertauer Hallertau. See spalt hop region and tettnang hop region. Technically, most Mittelfrueh currently grown in all three German areas is “clonal selection 102,” a clone selected and propagated by the Hop Research Institute in Hüll in the Hallertau. It owes its selection to its vigor and its conformity to the variety’s flavor standards. Through much of the 20th century, Mittelfrueh was the predominant hop grown in the Hallertau.

Hallertauer Mittelfrueh, often referred to as simply “Hallertau,” is a low-yielding hop, averaging about 1,250 kg/ha (1,115 lb/ac) that is susceptible to downy mildew and especially to verticillium wilt. Either may be fatal to the plant, especially the wilt. An outbreak of downy mildew in the Hallertau in the 1920s was responsible for the founding of the Hop Research Institute in Hüll in 1926. The new Institute’s nearly exclusive mission was to search for hops that were less susceptible to these diseases and then find ways to control the diseases themselves. In the mid-1950s, an especially aggressive strain of verticillium wilt began to spread in the Hallertau and even caused the infected fields to collapse into commercial non-viability. Because all efforts to find effective means of controlling the wilt had failed, the wilt was so widespread by the 1970s that much of the area was replanted with other hop varieties that were known to be more wilt resistant. See brewer’s gold (hop), hersbrucker spät (hop), and northern brewer (hop). New aroma cultivars that could stand up to the wilt were also released by the Hüll Institute. See perle (hop). Whereas in 1970, 58% of the Hallertau acreage was planted with Hallertauer Mittelfrueh, by 1990, that number had dropped to only 1.5%. Acreage increased in the 1990s, however, largely because of a continued high demand by brewers around the world and because of—by then—improved agronomic practices. Currently, Hallertauer Mittelfrueh represents slightly more than 10% of all German hop plantings.

Because of the reputation of Hallertauer Mittelfrueh and continued demand for it by specialty brewers, the Hüll Institute continues to be focused on breeding hops with similar brewing characteristics that have made Mittelfrueh famous, but with better disease resistance and higher yields. Of these, Hallertauer Tradition has been the most successful variety. The more recent Saphir and Smaragd show much promise, too. See hallertauer tradition (hop), saphir (hop), and smaragd (hop).

Many American brewers in the 1970s wanted a secure source of Hallertau, largely because of the wilt-related production problems in Germany. Thus, they explored other options, the most obvious of which was to grow the hop in the United States, where the wilt was less of a problem. Hallertau plant material was, therefore, imported and propagated in the New World. Much of the material was clearly genuine Hallertauer Mittelfrueh, but some material seems to have been mixed up with some other unknown variety, a problem that is not uncommon in the industry. Hallertauer Mittelfrueh plants in Germany produce red-stripe bines, as do genuine plants in the United States, but the questionable Hallertau plants produce green bines without the telltale red stripe, and the hops themselves are more Fuggle-like than Hallertau-like. Because many brewers were subsequently disappointed by the American-grown Hallertau found in the trade, these transplant efforts were largely unsuccessful. One exception is Hallertauer Mittelfrueh grown in northern Idaho. See idaho (northern hop region). The second pathway to a secure source of New World Hallertau was through breeding Hallertauer hybrid hops with better yields, but similar flavor characteristics. See crystal (hop), liberty (hop), mount hood (hop), ultra (hop), and vanguard (hop).