English to German Science Food & Drink Brewers\' yeast

Here's the definition:

A method of inserting a small portion of a previous batch of fermented food into the start of new batch of food to be fermented.
http://www.creativeglossary.com/fermentation/backslopping.ht...

Text: Scientists, like Louis Pasteur and Emil Christian Hansen, pioneered microbiological techniques in the 19th century, but the yeast strains they dealt with had probably become accustomed to the conditions present in beer production long before that time. Through rather unsophisticated inoculation and maintenance techniques using a practice known rather unappealingly as “backslopping”, individual yeast strains were gradually selected for certain traits.

Inverted commas already in text. I did not add them.