Mashing in, wort transfer, the boil and hop addition
In ‘normal’ times, Tuesday is brewday here at Bellfield.
We thought you might be interested in some of what goes on during the initial stages of the brewing process and so Sally, our assistant production brewer, has taken some photos along the way.
First, the grain (malted barley and flaked maize, in our case) is carried up via the hopper and auger, into the hydrator where it’s mixed with hot water and drops into the mash tun.
We use a big rake arm inside the mash tun to spread the grain out evenly as the mash tun fills up with water at around 65°C.
The grain then sits steeping for about an hour to extract the sugars out of the grains – this is what we call ‘the mash’.
We then draw the liquid (called ‘wort’ ) off the bottom of the mash tun.
Initially the wort running off the mash is full of suspended solids mostly pieces of grain. It is ‘brown and bitty’.
We ‘vorlauf’ (recirculate) the wort back through the mash; the grain bed acts as a filter to catch the ‘bits’.
The first run off is dark brown, due to the concentration of sugars released from the grain.
Once it is clear of solids we stop the vorlauf and begin the transfer of the wort, to the kettle.
While we do that, we spray more hot liquor onto the top of the grains – this is called ‘sparging’.
This lets us wash all the sugars out of the grains to achieve our required original gravity (sugar concentration) which will determine the eventual ABV of the beer.
During sparging, the wort gets lighter and lighter in colour.
Once we’ve drained all the wort off the grain, the grain is ‘spent’.
It’s emptied out and taken to a local farm, to be used as animal feed.
We then end up with around 2200 litres of ‘wort’ in the kettle, and this is then boiled, usually for about an hour.
This is the stage where we add hops.
The first hops are added for bitterness – that typical bitter taste at the back of your throat that you taste in beer.
If we add hops later in the boil - and especially if we ‘dry hop’ the beer - they don’t give us any bitterness, but they help create the aroma of the beer.
(So our new Jex-Blake Mosaic IPA for example, is a single-hop beer. It has juicy, tropical fruit aromas of pineapple and mango and pine and citrus flavours, thanks to the Mosaic® hops we’ve used at three stages of the brew: in the boil, in the kettle and then dry hopping.)
Once we’re finished boiling, we then draw the wort off the bottom of the kettle, and send it through the heat exchanger into the fermenting vessels.
This is where the magic happens and we’ll cover this next stage in another blog.