Brewing: Ale and Lager

So after writing the last post about my favorite beer in Houston, I realized that many probably don’t know a lot about brewing and the differences between a Lager and an Ale.

Brewing Process

I will start with just a quick basics of brewing beer. Even though I know the basics I have never tried myself (besides Kvas) but would like to sometime. Maybe i’ll tell you about my experiments when I do them. Anyways the basic process consists of 7 steps:

1. Mashing

Mashing is the process of mixing the grain with water and heating the mixture to allow the enzymes to break down starch into sugars. This is usually done in a mash tun, that has a fake bottom for separation purposes.

2. Lautering

Lautering is done in a lauter tun which separates the extracts from the spent grain. There are 2 stages, stage one is the extract is separated in undiluted state and stage 2 when the grain is washed with hot water to get the rest of the extract.


3. Boiling

Boiling is the process typically used to get rid of bacteria and it is used for this exact purpose here. The extracts are boiled which ensures sterility. In addition hops are added at this stage which give each beer its own unique flavor and aroma. Standard boil kettles can be used to boil the wort.

For my ChBE friends Boiling is a very energy intensive process so usually energy recovery process is used. Vapor that comes off of the boiler is passed through a kettle vapor condenser to get some of the heat energy back.

Another side note: After boiling the wort has to be cooled so another heat exchanger is used here to bring the wort down to fermenting temperatures and so that the yeast can be added.

4. Fermenting/ 5. Conditioning

Process that starts with the addition of yeast to the wort. Here the yeast breaks down the sugars from the wort into the carbon dioxide and alcohol. CCT’s or cylindroconical tanks are usually used for the fermenting process. This allows the yeast and other “junk” to fall to the cone of the CCT and be easily flushed after the fermenting process. A special device “Spundapparat” is put on the tank in order to keep pressure and carbonate the beer.

Other conditioning is done by cooling the beer to almost freezing while keeping the pressure to prevent the beer from going flat, but still getting all of the proteins and yeat and unpleasant flavors out of the beer.

6. Filtering

Not all beer is filtered. Some of the best beer is not. (As I will later write about the unfiltered Pilsner I had at Hay Merchant) But if the filtering procedure is done, different types of filters can be used to get rid of the “fogginess” of the beer and give it a clear and typical beer look.

Here is a good example of a filtered on the left and unfiltered beer on the right:


7. Filling

Simple: put the beer in containers, whether its bottles, kegs, casks, etc.

Ale vs Lager

Each of these steps is done for Ales and Lagers, but they have a slightly different fermenting process. Ales are known as top-fermenting yeasts, and Lagers as bottom-fermenting. This is because Ales create a foam on the surface during fermentation and the Lagers yeasts tend to collect at the bottom of the fermenting vessel. The Lagers are fermented at a lower temperature sometimes as low as 5-10C. Lagers are also stored in a close to freezing environment for 30 days or longer, which lets the beer mellow and gives it a smoother taste.

Here are the differences between a Lager and an Ale in a quick table:



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