Fermentation Process For Beer – Why the Bubbles?

You probably came to this link wondering how much I could possible talk about the

Fermentation process for beer
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fermentation process for beer. Quite frankly, I am wondering the same myself. Fear not, here I go anyways.

How Does Fermentation Fit in the Process?

The brewing process is relatively simple on paper. You create a wort, ferment it, package the beer, and then enjoy it.

When you set out to make a batch of beer, the first step is to create the wort. In simple terms, you have created sugar water using the ingredients in your kit. This is pretty close to your beer except you are missing the most notable ingredient in the beer…the alcohol. Unless you want non-alcoholic beer you will move on to the next step.

Once you create your wort, you pour it into your fermenter and then add some yeast. I will go into more detail below, but the high-level overview is the yeast converts the sugars into alcohol.

Your recipe will guide you on when fermentation is done, but, when it is, it is then beer. Really really flat beer. You need to package the beer and allow it to carbonate. Most new brewers will bottle their beer with a little added priming sugar to help carbonate.

I will not go into enjoying the beer because you have come this far and I know you didn’t brew all that beer to just give it away. Now, let’s dig into fermentation in a little more detail…

Why The Bubbles?

Fermentation bubblesSo I won’t be going into some larger biology/chemistry discussion to describe fermentation. It took me some time (and lots of reading) and there is still a lot I don’t know, but I can at least explain what is going on.

As I said earlier, your wort is essentially sugar water. Your recipe kit will come with a yeast that is selected for you. There are a lot of factors that go in to deciding which yeast to use, but know that it is selected based on the sugars expected in your wort.

Now, the answer to your question…why the bubbles? Well, as the yeast converts the sugars into alcohol carbon dioxide is formed. This will cause your fermenter to pressurize and eventually the carbon dioxide will make its way out of the airlock.

In general, for the recipe kits used by most beginners the fermentation process for beer is relatively simple. So what could possibly go wrong?

How to Have Bad Fermentation – Sanitization

I am pretty sure I have discussed sanitization in almost every post so far. There is a reason, poor sanitization can lead to bad beer.

Your yeast will produce alcohol (mostly) and some other components that flavor your beer. Keep reading in the next section for more on that, but what happens if you do not sanitize your fermenter?

Well, those other components can be esters (fruity notes) and phenols (spicy notes). Your yeast in your kit is designed to get the optimal mix of alcohol, esters, and phenols during the fermentation process for beer. You know what else acts like yeast? Bacteria and microorganisms…

If you yeast is specifically designed then you probably don’t want anything else “help” convert the sugars. That is what the bacteria and microorganisms will do and you really can’t control what they make (same goes in your bottles too). Like I said earlier, I won’t go deep into the biology, so just remember sanitize for better beer.

What Else Could Mess It Up?

There are two more ways that the fermentation process for beer can be thrown off: too much oxygen and poor temperature control.

Too Much Oxygen: The yeast does need some oxygen to work, but fermenting without the lid on your fermenter would be bad for your batch. There are plenty of contaminants in the air that could cause issues with the fermentation and, depending on the beer type, you could oxidize your beer.

You are probably wondering why I mentioned that. Your brand new kit has a fermenter and air lock for that purpose and you are following the directions. Well, I have seen this happen two different ways:

  1. Your wort was a little warm going into the fermenter. As it cools (before fermentation really kicks in), it can pull a vacuum which could suck the water back into your fermenter. I have seen this happen to a friend so it is a possible issue.
  2. Fermentation was active and foamed up in the fermenter. If there is enough foam, it could get into the air lock. When it dries, it will plug the fermenter and the carbon dioxide won’t have anywhere to go. If this happens, something will come off (probably the lid to your fermenter from experience)

Poor Temperature: I mentioned above how closing up your fermenter too how could lead to pulling a vacuum when it cools. Did you know that is could also throw off your fermentation?

Remember, the yeast is selected for your beer type and has a specified range of temperatures where it will work effectively. If your temperature is not within that range, the ratio of alcohol, esters, and phenols will change and your beer will taste different.

As long as the temperature is close you shouldn’t see too much difference…unless you are a trained beer taster.

There You Have the Fermentation Process For Beer

So we did it! Enough information here to know what to watch for: sanitization, temperature, and oxygen (more specifically a well functioning air lock). If you do well on these three you will get some great beer in the end.

If you have any questions on what to get, comment below or email me at nate@drinkgreatbeers.com.


Fermentation process of beer

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