We now know that Barley (or other starch sources) are malted before they could be used. At this point, the grains are simply called 'malt'.
Here's how things go down in the brew house fro here on -
Step 1 : Milling
During this step, the malt kernels are broken down and seeds separated from the husk. This exposes the carbohydrates and sugars which will be later extracted. The milled malt is now called grist.
Step 2 : Mashing
The grist obtained in the previous step is now mixed with hot water in what's called a mash tun. Here's what it looks like -
Mashing allows the natural enzymes present in grist (our milled malt) to break down the starch into simple sugars
. These sugar molecules on release, mix with the water and this sweet liquid is called wort
Step 3 : Lautering
This step involves separating the soaked grist (called mash) from the wort. It's done by passing the mash-wort mixture into another vessel which has holes at the bottom (called a lautering tun). This helps in straining the wort out into another vessel for further processing.
Step 4 : Boiling
Once the wort is strained out, it is gathered in a copper vessel to be boiled with hops. During the boil -
- The wort gets sterilized to remove unwanted bacteria.
- Hop releases it's bitter flavour which gets mixed with and removes the sweetness of the wort.
- Wort becomes more concentrated and aromatic.
Step 5 : Wort Separation via Whirlpool and cooling
After the boil, the mixture of hops and wort is transferred to a vessel called a whirlpool. This allows the hop and remaining grist or malt particles to settle down separating the wort.
After separation, the wort is run through heat exchange channels which cool it down to a temperature (20-26 degree celsius), apt for addition of yeast and fermentation.
Step 6 : Fermentation
After cooling, the wort is passed into a fermentation tank where yeast is added. Yeast turns the sugar present in the wort into alcohol, carbon dioxide (responsible for the sparkle) and other components. This is when the wort starts to become beer. There are two major ways this is done and both produce majorly different results -
- Warm fermentation - This is done at around 15-20 degree celsius. Ales are usually fermented this way and are ready to consume within three weeks of fermenting.
- Cool fermentation - This is done at about 10 degrees celsius, post which the beer is stored for 6 months at a near freezing point (a process called lagering) allowing . Lagers are prepared this way. The yeast used for this kind of fermentation is different from the ones used for warm fermentation.
Step 7 : Ageing or maturing
Once fermented, the beer is moved to a cleaner container, away from the dead yeast and other debris. Aging the beer could take from several weeks to months to even years, depending on the desired outcome.
Next up - Cool resources ->