How to Ferment Beer – 5 Steps Explained

Alright so you are either just starting to look into making beer or you are just about to wrap up brew day and it is time to ferment your newly created sweet nectar of the gods; and now you are quickly scrounging around trying to figure out how to ferment beer. Hopefully the latter is not the case, but either way have no fear and read on…

Whatever the case may be Big Robb has you covered because in this post I am going to give you a quick crash course on how to ferment your wort and turn it into delicious beer… after reading this post you will be a fermenting wizard…

So let’s get at it!


What Equipment You Need

So the equipment is pretty basic when it comes to fermentation. It makes no difference what method of brewing you are engaging in, whether it is beer kits, partial mash brewing, all grain or BIAB. The process and equipment is the same.

You are going to need:

1) A Primary Fermenter

This is the vessel or container that you are going to ferment the beer it. Some people just use 5 gallon plastic buckets, while others use the glass carboys that most wine makers use to make their wine, and than others uses fermenters designed for beer making (my preference).

I have a few buddies who use the glass carboys and they work fine but I do not like that they are not opaque; meaning they are clear and light can get in. Light can cause problems with your beer turn it skunky tasting and it is why most beer bottles are brown or green and not clear.

The other reason I do not like the carboys is that they are trickier to clean due to the mouth of them being so small. Fermenters designed for making beer have nice wide mouths on them designed to be able to clean the fermenter after the fermentation is complete.

If you do decide to use a carboy than put a blanket or towel around it or of course you could put it in a completely dark space in your home. And when it comes to cleaning it give it a good rinse with hot water and than fill it up with warm water and add PBW or OxiClean to it and let it soak for a couple of days and the gunk build up should come off for you.

So as indicated I personally prefer a fermenter that was designed for making beer. They are opaque so the light does not get in. They typically have a spigot at the bottom so you can pour the beer from it without a siphon. And they have a nice wide mouth that allows you to get easier access for dry hopping, adding any fruit additions and of course as we discussed for cleaning.

My two favorite fermenters are:

Coopers Fermenter and the Speidel plastic fermenter. I have both of these fermenters and I am torn between which one would be better than the other. They both work great and make fermenting a snap.

2) A Secondary Fermenter

The jury is out on whether you need a secondary fermenter. If I am very upfront I very rarely if ever use a secondary fermenter. But those who do swear by them.

The purpose of a secondary fermenter is to help clear and condition your beer. So beer gets better with age and sitting in a fermenter up to 4 weeks makes for a better tasting beer than rushing it out of the fermenter and into bottles or a keg within 5-7 days.

So let’s back up a bit here… during fermentation what happens and what you will notice is a layer of krausen form at the top of the beer. You will also notice matter floating in your beer as well as moving around during active fermentation. So where does this “stuff” go? Why obviously to the bottom of the fermenter. This stuff is of course the krausen, but also grain particles, hop particles and dead yeast particles.

When they drop to the bottom as a collective group they are known as the trub. So letting your beer sit on the trub for 1-2 weeks is actually a good thing. (depending on the style of beer). Anything longer than that and some people claim it gives the beer off flavors. I concur that if you let your beer sit on dry hops for too long that flavors you do not want will occur.

So this is where secondary fermentation comes into play. People rack their beer from the primary fermenter over to a clean and sanitized secondary fermenter. As for the container it would be the same type of container as you used during primary fermentation. They rack their beer and leave it for another couple of weeks to finish fermenting and it also helps condition and clear the beer.

By getting the beer off the first fermenters trub you are leaving a lot of that “stuff” behind and while in the second fermenter even more of the “stuff” will drop out of suspension and when you go to bottle or keg your beer in theory it should be much clearer than if you bottled/kegged from the primary fermenter as you are leaving all the “stuff” behind.

However what I have found is if you cold crash your beer, meaning put it in a fridge or in a container of some sort at fridge temperatures for two days after fermentation is completed your beer will clear up incredibly well and as such there is no need for the secondary fermentation process if your goal is a clear beer.

3) Air Lock or Blow off Tube

OK so for most beers you are going to brew you will only need an air lock on your fermenter. An air lock is simply a gadget you place in the hole on the top of the fermenter to allow C02 to escape out the top of it but will not allow Oxygen or any bacteria, bugs etc to get into your beer.

We have all seen these gadgets. They bubble away during fermentation and as home-brewers we all love to sit and stare at them during fermentation. Nothing better than watching that little air lock bubble up and down as the yeast go to work making you your brew!

You will also need StarSan, which is a food grade sanitizer. Besides sanitizing your fermenting equipment to include the fermenter and airlock, etc… you will also fill the airlock up to the fill line with the StarSan.

As for the blow off tube you would use this if you have concerns that your fermentation will be so active that you are going to blow the airlock right out of the fermenter or jam it with krausen. This could happen if you have a high gravity beer and there are lots of sugars to ferment or if you have brewed more than a single batch and have really filled your fermenter up close to the top of it with wort.

A blow off tube is basically just a liquid tube or hose that you put into the “bung” that the airlock would typically sit in. You than run the other end of the hose down into a bucket, pail, pop bottle, etc that is filled with StarSan. This way all of the “stuff” bubbles out of the fermenter and into the bucket, pail, pop bottle instead of out of the air lock and onto your floor.

4) And lastly you may need an Auto Siphon.

If you are using a glass carboy or just a 5 gallon bucket to ferment in than you will need an Auto Siphon to transfer your beer to and from the container. Be sure to sanitize the Siphon before each use with StarSan.

The 5 Beer Fermentation Steps

OK so you have your equipment and are ready to fermen

Home brew beer in beer glass on coffee table
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t up some homebrew baby!

The actual steps involved are not that difficult and are really quite straight forward.

Step 1) Chill Your Wort to Right Temperature

The first thing to do is to make sure you have chilled your wort down to the right temperature to pitch your yeast.

I cover 5 ways you can to that on the following post: How to Cool Wort

However the basics of it are you want to make sure you get your wort (not fermented beer) down to the temperature that the yeast you are using calls for. Typically, that will be around 65 – 70 degrees F (18 – 21 C).

If you pitch the yeast (add it to the wort) while the wort is too hot it can kill the yeast. And if you pitch the yeast and the wort is too cold it can put the yeast to sleep. It is better to put the yeast to sleep as it will wake back up as the wort warms up to room temperature.

Step 2) Add Wort to Clean & Sanitized Fermenter

The second thing is to now add the chilled wort to your cleaned and sanitized fermenter.

It is imperative that your fermenter is cleaned and sanitized. If you mess this up and get lazy here you have wasted your time and money brewing this batch of beer as it is going to go bad. Which will result in you having the terrible experience of having to pour it down the drain. Not Fun! Doing so has made many a tough man drop to his knees in tears!

Check out this article on how to clean and sanitize your equipment

Step 3) Pitch Your Yeast

The third thing you do is to now add the yeast to the fermenter. Make sure you open the yeast with a sterilized knife or scissors and just slowly pour the yeast around on top of the liquid in the fermenter.

Once it is all added, take a sterile spoon and give it a good stir, this is the ONLY time during the brewing process Oxygen is a good thing.

As for what yeast to use, typically your recipe will tell you which yeast to use, however I am a huge yeast snob and prefer Safale us-05 for American style beers and Danstar Nottingham Ale yeast for my European Style beers. You can’t go wrong with either of these yeasts.

Step 4) Cover It Up

The forth step is that you simply put the cover and airlock on the fermenter (don’t forget to add Starsan to the airlock) and you place the fermenting pail away in a room in your home and let it ferment.

The key here is to make sure the room you ferment in is at the right temperature. Again same thing applies as when you are pitching the yeast. If the temperature is to warm or hot it will create terrible off flavors in your beer and ruin it. If the temperature is too cold it will put the yeast to sleep and nothing will happen.

Room temperature is usually fine. You want to shoot for a range of between 65 – 70 degrees F (18 – 21 C). A little warmer than that will also work, but if you get over 80 degrees F you are in for trouble.

Now what we have just talked about is for fermenting Ale’s and not Lagers. Lagers are a completely different animal and if you have interest in brewing a Lager I would recommend you check out this post: What is the Difference between Ale and Lager?

Step 5) Keep Your Hands Off It

The fifth and last step is you simple leave it alone. Let it sit for 2 weeks and you can be assured that all of the fermentation is over and the beer will be ready to be bottled and kegged.

You will notice that after 4-5 days what I call active fermentation is over. Meaning all of the violent movement in the fermenter is done.

And yes most of the fermentation is actually done at this point. And I have bottled beer within 7 days of fermenting it and it turned out just fine. But if you let it sit for the two weeks you are guaranteed to have better beer. Beer is simply better with time.

You can of course also use a hydrometer to take readings during fermentation to confirm when it has completed. If you wish to do that the following post is how to use a hydrometer to do so. How to Read a Hydrometer

Get To Fermenting

And that is it my friend. Pretty straight forward stuff.

Your next steps after fermenting beer are to either bottle or keg your beer.

The following posts will help you do both:

Bottling Homebrew Beer

Kegging Homebrew

I trusted you enjoyed this post on how to ferment beer and even more so I trust you found value in it.

If you have any questions at all do not hesitate to ask me in the comment section below. I will be sure to reply to you.

Cheers and happy fermenting!

Big Robb he gone!

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