There are good bacteria, and then there are bad bacteria. The latter of the two can be, quite literally, deadly. The former, however, the good ones, are essential: we need them to stay healthy and to make some of our favourite foods – foods like cheese, for example. If you want to harness the help of these good bacteria cultures, you need above all to give them the kind of conditions they like; and since I’m going to need their help during my experiment, I run them a nice, warm milk bath on my stove as a way of currying their favour. Next to me is a do-it-yourself cheese-making kit (ordered from www.kaese-selber.de) and a whole host of cultures just waiting – so I hope – to get to work.