How to make home-brewed beer: the science behind the beer

Everyone likes to make something homemade with their own hands and enjoy it the moment they eat it, so why not do the same with beer? In this post we are going to tell you all the secrets behind this ancient drink, how to make it at home and all the science behind it.

Although it may not seem like it, brewing beer is an extremely complex process. simple and in a few two weeks the most critical point of the whole process is to avoid possible contamination that could interrupt the fermentation process and spoil the final result.

What ingredients are needed to make home brewed beer?

The ingredients you need are four:

• malted barley
• hops
• yeast
• water

And since it is a home brew, we can play with different additives to “tune” our beers, such as fruits, spices, sugars, etc.

So, how do we brew it?

1. The first step is to make the barley juiceIf we are going to consider that we want to make 10 litres of beer, we first add 10.5 litres to a pot to try to compensate for possible losses during the cooking process. And with the help of a thermometer we control the temperature and let it boil during 1 hour and a half at 85ºC. This allows us to extract all the sugars from the grain into the water, thus obtaining the juice.
2. While we are cooking, 45 minutes after we have started the cooking process add the hops we have chosen for our beer and leave it until the brew is complete.
3. Once the time has elapsed, we transfer the wort to the tank in which we plan to ferment our beer, and we wait for the temperature to drop.
4. Once the wort is at room temperature we add our yeast and close the fermentation tank. If we don’t have a fermentation vessel, we can use previously disinfected glass bottles and put a balloon punctured in the nozzle to let the CO₂ but do not enter oxygen. After about two days, you should be able to see the gas coming out.
5. After leave to ferment for at least 2 weeks we proceed to distribute the juice in different bottles where we plan to keep our beers, and we add to them 1 spoonful of sugar at the bottom of the bottle before filling, and once filled, close the bottle and leave to ferment for a further 7 days. This step is crucial to try to get our beer to have the gas strength typical of commercial beers.
6. And that’s it, serve very cold and enjoy!

What’s the science behind it all?

The science behind the beer can be divided into 2 fundamental processes.

The first is malting, which we explained in an article on this website which you can find here.

The second step is fermentation, and it is the most fundamental process, as it is from this that the beer is made to contain a reasonable alcohol content.

To do this, the yeast that we add to the wort uses the sugars that have been extracted from the barley and through these processes transforms them into CO₂ and ethanol.

Depending on the type of yeast and the temperature at which fermentation takes place, there can be 2 groups of beers. Top-fermented beers, usually known as “ale” and bottom-fermented or “lager” beers and a small minority group of spontaneously fermented beers.

Ale beers are fermented at a temperature between 15-25 degrees Celsius and lagers are fermented at 5-9 degrees Celsius. Spontaneously fermenting beers are produced at room temperature.