How far back does biotechnology date?

The term is largely believed to have been coined in 1919 by Hungarian engineer Károly Ereky.

This is from wikipedia In the 1860s, institutes and remunerative consultancies were dedicated to the technology of brewing. The most famous was the private Carlsberg Institute, founded in 1875, which employed Emil Christian Hansen, who pioneered the pure yeast process for the reliable production of consistent beer. Less well known were private consultancies that advised the brewing industry. One of these, the Zymotechnic Institute, was established in Chicago by the German-born chemist John Ewald Siebel. hope this helps

A. radioactive dating