Boiling and Topping Up
The wort needs to boil for 60 minutes and there is plenty to keep you occupied during this time. Put the kettle on - not just for a coffee but also because your yeast will need pre-boiled water which has cooled to below 23°C. Wash up and put away your sparging equipment and the mash tun. (I put the spent grain (and hops) on the compost heap, some brewers use the stuff as a mulch on their flower beds.) You also need to sterilise your immersion wort chiller. Don't forget to weigh out the remaining batches of hops and have the Protafloc to hand. Boil your filter bag for 15 minutes to sterilise it.
(Common sense dictates that your wort will reach boiling point faster if you put the lid on while heating. But I suggest you don’t keep the lid on (or fully on) once boiling begins. There are two reasons for this. Firstly, as a safety issue – having the lid fully on increases the chances of a boil-over. Secondly, a school of thought says that boiling in an uncovered pot, or in a partially covered pot, drives unwanted compounds out of the wort that can give off-flavours. The most common of these is dimethyl sulphide which can make your beer taste like boiled cabbage. Another school of thought says it makes no difference whether the lid is on or off during the boil, so as always, the choice is up to you. I tend to take the middle road and boil with the lid partially on – that helps to achieve and maintain a vigorous rolling boil but also allows these unwanted compounds to escape in the steam.)
As per the recipe, when the wort starts to boil add the first batch of hops and if called for in your water laboratory analysis, the Dry Liquor Salts. Write down the time of the start of the boil in case you forget, and work out (and write down) what time you should add your next batches of hops by referring to the recipe. Don't forget to add a quarter of a teaspoon of Protafloc granules 15 minutes from the end of the boil.
So you've followed the hop schedule in the recipe and added the right batches of hops and finings at the appropriate times and the 60 minute boil has come to an end. Stretch the filter bag over the top of the fermentation bin, switch off the heat and CAREFULLY jug out the wort into the bin, through the straining bag.
When all the wort has passed through, hold up the straining bag to drain the hops. Be careful with this stage and try not to splash - this stuff is HOT! Finally discard the straining bag containing the hops by dropping it into a pan or a bucket. I wouldn’t recommend emptying the bag until the hops have cooled as they get very hot.
You’ll remember the recipe is for 25 litres. Simply pour your later spargings from your stockpot into the fermentation bin to make up the difference (you'll remember how you measured what 25 litres looks like in your pan on 'The Mash' page). Now it’s time for Cooling and Pitching...