Alfred Wöhlk, also: Woehlk, Wøhlk, (1868–1949) was a Danish chemist and pharmacist. With his historical detection reaction from 1904, the lactose content of dairy products can be visualized. This is useful because many people are lactose intolerant and avoid dairy products. Countless pharmacy students, but also physicians, laboratory assistants, and recently also chemistry teachers know the Wöhlk test.