Effect of Growing Conditions on α-Acids Content of Hops Grown in Mexico. J. R. Francke, A. B. Muñoz, and M. Treviño, Depto. de Proyectos Especiales, Instituto Technológico y de Estudios Superiores de Monterrey, N. L., Mexico. J. Am. Soc. Brew. Chem. 40:0050, 1982.

In an 11-year project aimed at establishing the cultivation of hops in Mexico, a number of old and new varieties were grown at various locations in the northern states of Baja California, Chihuahua, and Nuevo León. The range of soils, climates, day lengths, and other factors tested were greater than in any published study on hops known to us. Certain standard varieties, notably Late Cluster but also Talisman, Cascade, and Comet, were grown in every location in every year, permitting us to establish the effects of the various factors on the yield and quality of these varieties. Established varieties require days 1-2 hr longer than Mexican locations can provide. The missing light can be supplied by overhead lights, or new varieties can be bred that do not require illumination. A short period of frost in the winter is essential to break dormancy. The highest α-acids contents of 10-16% are found at summer temperatures in which the daily maximum ranges from 28 to 32° C and the daily minimum from 5 to 10° C.

Keywords: α-acids, Day length, Environment, Maximum temperatures, Minimum temperatures