In order to prepare your ingredients for fermenting you’ll first need to boil the extract with water, adding hops and other flavours at various stages of the process. When complete this liquid should be given a good stir to oxygenate it, and cooled as quickly as possible – we do this by only using half the water for the boil and keeping the remainder in the fridge. Putting your boiling pot in a sink of iced water also helps.
Once the liquid has cooled (to below 24°C/75°F) you’re ready to add the yeast and allow it to get to work on those sugars. Yeast is supplied in various liquid or dry forms, the use of which varies according to type and manufacturer. For the beginner we recommend individual sachets, which you should add according to the instructions on the packet. For most beers in this book a warm (but not hot) room at around 15–24°C (60–75°F) is sufficient for fermentation, although lagers prefer it cooler.