How To Ferment Beer at Home (Easy Explanation)

Fermenting beer in the comfort of your own home is not as complicated as it may seem. All it takes is a little patience, determination, and level-headedness. The perfect homebrew will be within your reach if you’re eager to practice, experiment, and learn from your mistakes.

You can ferment beer at home by making sure that everything you use is cleaned and sanitized. Then, bring your wort down to the ideal temperature, pitch the yeast, and wait. Take note of the original and final gravity to determine your beer’s alcohol content and sweetness before bottling.

In this article, I will talk you through the process of preparing your wort for fermentation, correctly pitching your yeast, measuring original and final gravity, using additives, and, finally, bottling your beer. Let’s begin!

1. Clean and Sanitize Your Tools and Equipment

Wort — the mixture of malt and other grains fermented to produce beer — is prone to contamination, especially when its temperature decreases. 

To help minimize the risk of infection, clean and sanitize all the tools and equipment you’ll use to ferment your beer. 

Cleaning involves the removal of dirt, dust, and other unwanted particles on various surfaces. This typically entails the use of water, detergents, and scrubs to eliminate unwanted buildup and debris. 

Cleaning alone does not guarantee the safety of your tools and equipment, particularly involving sensitive processes like fermenting beer, but it is a necessary step preceding sanitation. 

On the other hand, sanitizing involves the elimination of harmful bacteria, viruses, and microorganisms from surfaces. This usually calls for tougher products that can help make your tools and equipment safe for fermenting beer. 

The FastRack No Rinse Brewing Sanitizer (available on Amazon.com) comes in a non-foaming powder formulation that makes sanitizing reasonably easy. This one-step sanitizer requires no rinsing and works by utilizing the proven sanitizing abilities of hydrogen peroxide.

2. Bring Your Wort Down to Pitching Temperature

Cooling your wort down to the ideal temperature depends on whether it’s a lager or ale strain. Lager strains need to be brought down to about 45-55°F (7 to 13°F), while ale strains can start at about 70 ºF (21°F). 

Remember that your wort needs to be cooled fast to help thicken its long protein chains. This crucial step will bring out your beer’s flavors and produce haze. 

You also want to cool your wort down as fast as possible so that you can add yeast as soon as you can. Yeast will protect your beer. It will also consume the sugars in the wort to produce alcohol and carbonation. 

You should never add yeast to hot wort. Doing so may kill some of the yeast and produce offensive flavors in your beer. 

To quickly bring your wort down to the ideal pitching temperature, here’s what you can do:

  1. Fill your sink with water and ice. Make sure that the water level reaches about halfway up your wort vessel.
  2. Place your wort vessel into the icy water. Ensure that the vessel doesn’t tip over and that no water or ice gets into contact with the wort.
  3. Stir the wort with a spoon. Stir gently and make sure that your spoon is sanitized. 
  4. Use a thermometer to check your wort’s temperature. It typically takes about 15 minutes to achieve the desired result. 

3. Move Your Wort Into the Fermentation Vessel 

Grab your strainer and position it securely over your fermentation vessel. This helps ensure that hop particles will be strained out. They look like green sludge enmeshed in the wort.

It’s essential to filter out the hops to ensure that you end up with a clear brew. Moreover, hop particles might clog your fermentation or carboy and might even cling to the sides, causing a huge mess. 

Aside from using a strainer, there are several other ways to filter out your hops. Here are some of them: 

  • Hop bag. These are typically made of nylon or muslin. Make sure to tie them securely so that they don’t burst open. 
  • Copper scrubber. You can attach this at the end of your kettle tube so it can filter out hop particles as you pour the cooled wort into your fermentation vessel. 
  • Hop blocker. This kettle strainer is on the expensive side, but it’s a great investment if you like brewing beer at home. The Hop Blocker from Blichmann (available on Amazon.com) captures up to 95% of hop pellets and particles. 

It is advisable to pour in the wort vigorously to introduce oxygen into it. The yeast will utilize this added air for faster growth.  

Top up the fermenter with brewing water, ideally up to the 5-gallon mark. Secure the lid and shake the fermenting vessel vigorously to mix the wort and water and introduce more oxygen into the mixture. 

4. Take the Original Gravity

Take a sample from your wort to measure its original gravity. You can do this with the help of a hydrometer, turkey baster, or a wine thief. Make sure you set aside a sufficient amount of wort to fill your hydrometer sample jar. 

The original gravity measures the amount of sugars dissolved in the wort that will later be converted into alcohol during fermentation. These sugars will be consumed by yeast, jumpstarting the process of converting wort into beer. 

The original gravity is compared with the final gravity — measured after fermentation — wherein the difference dictates alcohol content. The higher the difference, the higher the alcohol content. 

Ideally, gravity is measured every few days to ensure that it is continuously declining. Gravity is associated with density, wherein the wort becomes less dense as more sugars are converted into alcohol. 

Never put the sample wort back into the fermentation vessel. This has been contaminated and might infect the rest of your wort. 

5. Pitch the Yeast

Yeast, a living organism, is a type of fungi that feeds on sugars to produce alcohol and carbon dioxide. It is highly efficient in doing its job, capable of consuming its own weight in sugar every hour. 

The type of yeast used for fermenting beer is Saccharomyces cerevisiae. Unlike alcohol, carbon dioxide is usually considered a waste product, but in the case of beer, this is what makes the beverage fizzy. 

Remember that yeast is highly sensitive. It won’t activate properly if it is not pitched at the right time and in the right way. 

Pitch your yeast only when the wort has reached the desired temperature. Also, “pitching” means throwing the yeast into the wort, similar to how baseball players pitch a ball. 

There are 2 main ways to pitch your yeast:

Dry Pitching 

Dry pitching is the easiest and simplest way to add yeast to your wort. Here’s how to do it:

  1. Shake the packaging and direct the yeast into one side.
  2. Cut open the packaging on that side and drop the yeast into your wort.
  3. Stir the mixture gently with a sanitized spoon.

Hydrated Yeast

Some homebrewers like hydrating dry yeast before pitching it into the wort. This jumpstarts the yeast, enabling it to work more efficiently.  

Experts say that this helps the yeast to better absorb water in its membranes so that fermentation is activated. Here’s how it’s done:

  1. Boil a cup or 2 (240-480 ml) of water in a bowl.
  2. Let it cool down a bit.
  3. Add your yeast and allow it to absorb.
  4. Cover the bowl. 
  5. Let the mixture sit for about 15 minutes. 

After about a quarter of an hour, the room should smell like you’re baking bread. Bubbles should have also formed on the surface. These are indications that your yeast is ready to be pitched into the wort. 

If there are no bubbles and the smell of bread doesn’t permeate throughout the room, this typically means that your yeast has died. 

Avoid using inactive yeast, especially if it concerns something you will be ingesting, since it may cause unfavorable reactions to those sensitive to its components.  

6. Seal Your Fermentation Vessel

Seal your fermentation vessel tightly shut. Attaching an airlock and stopper is a great way to ensure that fermentation transpires correctly and efficiently. 

An airlock ensures that bacteria, air, and other contaminants do not enter the fermentation vessel while allowing carbon dioxide to escape. 

If gas doesn’t have anywhere to escape, the pressure will continue building, eventually causing your lid to pop. The resulting explosion will undoubtedly be a terrible mess!

Don’t forget to fill your airlock with water up to the designated level. Make sure to attach it as tightly and securely as possible because any leaks will compromise the anaerobic atmosphere necessary for proper fermentation. 

You’ll know that your airlock is fitted correctly when you see bubbles forming in it. Active yeast will consume more sugars quickly and will thus create more bubbles in the airlock. 

The Brewland Carboy Airlock (available on Amazon.com) is perfect for homebrewing because it can quickly be taken apart for cleaning and sanitizing. It comes with a #6 rubber stopper, fit for a vessel with a top diameter of 32 mm (1.26 in) and a bottom diameter of 26 mm (1.02 in).

What Is a Krausen Blowout?

Krausen is the foamy substance that forms on top of your fermenting wort. It is not necessarily a bad thing since it indicates that the yeast is active and fermentation is vigorous.

Ideally, the krausen should crash in a couple of weeks, depending on the ale strain you used. This is when bubbles stop forming in your airlock, indicating that fermentation is complete. 

Even if you use a top-quality airlock and you’ve made sure that the lid is securely attached to your fermentation vessel, a blowout can still occur. 

This can happen when the yeast consumes sugars extremely fast, so fermentation is highly vigorous

When this happens, it means that carbon dioxide is being produced way faster than it can escape through the airlock. Bubbles and foam are formed vigorously, resulting in clogs and buildup. 

A krausen blowout starts as a leak in the airlock, eventually leading to a complete blowout. Sometimes, when the pressure is too much, the fermentation vessel explodes. 

How To Prevent a Krausen Blowout

There are several ways to prevent a krausen blowout. These strategies are not foolproof, but they can help reduce your risk of you having to clean up a huge, foamy mess. 

Here are some of your options:

  • Choose a sizable fermenting vessel. The extra space can better handle extreme pressure. 
  • Brew in smaller batches. The bigger headspace inside the fermentation vessel will help in preventing pressure buildup.
  • Use an anti-foam agent. The Fermcap-S Foam Inhibitor (available on Amazon.com) effectively prevents foam formation while increasing the bitterness of the beer. Yeast removes it from your beer when the fermentation process has finished. 

7. Monitor and Wait

Ale takes about 2 weeks to ferment, while lager takes around 6 weeks. A telltale sign is when the yeast clumps together and falls to the bottom of the vessel. This means it is already inactive. 

Another sign is when the gravity has stayed at the same level within the past few days. This means all the available sugars have been consumed and converted into alcohol. 

Lastly, when you see that bubbles are no longer forming inside your airlock, it means that fermentation has been completed.

For more information about how long it takes for beer to ferment, you can watch the video below:

8. Incorporate Your Beer Additives

Now that your beer is done fermenting, you may move it to a bottling bucket. This is where you may add the bottling additives you prefer. 

Beer additives can affect the brew’s flavor, clarity, and smell. It all depends on your taste and preference, so here are some additives you might want to consider:

Gelatin

Derived from animal collagen, gelatin is odorless and tasteless. It helps make beer particles settle out of suspension, resulting in a clearer brew. 

To add gelatin, this is what you should do (pertains to a 5-gallon batch):

  1. Set aside 1 cup (240 ml) of pre-boiled water.
  2. Add 1 teaspoon (5 ml) of gelatin and allow to dissolve. 
  3. Allow the mixture to cool down to room temperature. 
  4. Pour over your beer.   

Irish Moss

Irish moss is a coagulant made from seaweed that helps protein particles clump and settle out of suspension. To utilize this additive in your brew, simply pour half a tablespoon at the latter part of the boil (ideally on the final 15-minute mark).  

Isinglass

This additive won’t affect your brew’s flavor even though it is made from fish bladder. Just add a teaspoon to every 5-gallon (19 liters) batch of beer, and you can look forward to a clearer brew. 

Here is how you can use it:

  1. Prepare 1 cup (240 ml) of pre-boiled water.
  2. Add 1 teaspoon (5 ml) of Isinglass.
  3. Lightly stir, allowing the additive to dissolve.
  4. Wait for the mixture to cool down to room temperature. 
  5. Pour over your beer.

Calcium Carbonate

This additive, also known as “chalk,” helps enhance beer’s bitterness. It is a food-grade mineral blend that helps lower beer’s acidity by raising the beer’s overall pH. Use it sparingly and refer to the product label.

Ascorbic Acid

Popularly known as “vitamin C,” this additive gives your beer a bit of tang and scavenges for oxygen. Oxygen in beer produces stale flavors. Just half a teaspoon of ascorbic acid added to your beer will make a huge difference. 

Priming Sugars

Priming sugars are added to beer just before bottling to give it more fizz. It can also enhance your beer’s flavors and aroma. When you add priming sugars to your beer, you’re maximizing the yeast’s full potential by giving it an additional source of sugar.

9. Take the Final Gravity

Measure your beer’s final gravity. Follow the same procedure you observed when you measured the original gravity. 

Remember that the difference between the original and final gravity estimates your beer’s alcohol content. Furthermore, a high final gravity indicates that there are more sugars left after fermentation, resulting in a sweeter brew. 

10. Bottle Up Your Beer

When all is said and done, it is time to bottle up your beer. You can reuse commercial glass bottles or purchase new ones for your homebrew.

Reusing commercial bottles is obviously the cheaper option, but you must ensure that the bottles are thoroughly cleaned and properly sanitized. 

On the other hand, purchasing new glass bottles affords you the benefit of enjoying uniformity. A row of identical beer bottles on your shelves will be more aesthetically pleasing than random bottles of varying sizes, shapes, and colors. 

Here are some valuable tips to keep in mind during the bottling process:

  • Ensure all tools, equipment, and bottles are cleaned and sanitized. The bottling process exposes your beer to an increased risk of infection. 
  • Avoid splashing beer or pouring it vigorously. Introducing oxygen into your homebrew will significantly reduce its shelf life. 
  • Use a siphon or bottling wand. These help make transferring beer easier.
  • Invest in a bottle capper. Correctly capping your beer bottles is crucial to their preservation. This also helps ensure that your beer will not be contaminated by bacteria, dirt, or other unwanted substances. 

Final Thoughts

Making your own beer at home may seem daunting, but given enough time and practice, you’ll soon find yourself becoming braver in your attempts at coming up with your ideal brew. It will be a hit-and-miss experience at first, but the learnings will prove to be invaluable.

About HomeBrewAdvice

Hello, my name is Simon. Together with a group of writers I write about brewing beer and making wine. We all share a passion for the great things in life, such as making stuff from scratch.

The business of HomeBrewAdvice is to bring you great information, stories and product reviews from brewing at home, and making wine


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