Continuous fermentation system

For the millions of years before Morton Coutts (b. 1904, d. 2004) was alive, beer was brewed in pretty much the same standard way. The basic method was developed by the Egyptians, who in turn taught the Romans. They, in the process of conquering the rest of Europe, also brought the gift of beer - and good roads, apparently.

To make beer, Barley is soaked in water and allowed to sprout, then the sprouting process is stopped and the result is called 'Malt'. This malt is then crushed and mixed with hot water, and the resulting liquid taken away and renamed the 'wort'. Hops are added and the whole mess has yeast added to it. The yeast grows and grows until there is 5 times as much as there was initially. The fermentation process starts, converting sugars into alcohol. This carries on for a few days, and then the beer is aged for weeks or months before being bottled, and shipped to pubs, where you buy it, drink a lot of it and wake up with a sore head.

There's nothing wrong with this process, except that it takes a while and in the 1950s and 60s people were drinking more and more beer in New Zealand, and Coutts' employer, Dominion Breweries, was keen to quench their thirst.