What Does Infected Homebrew Beer Taste Like? (Plus What To Look For!)

As a homebrewer, it’s important to know the signs of an infected beer for health concerns and quality assurance. But what does infected homebrew beer taste like? 

While most infections are not harmful, the smell and taste of the brew may be unexpectedly sour, skunky, or musty. If the beer smells like vomit or has a severe mold issue, it should be disposed of rather than consumed. Infection in your homebrew usually results from improper sanitation and occurs with bacteria infiltrating the storage container.

If you want to know what to look for when trying to spot infection in your homebrew beer, keep reading!

What does infected homebrew taste like?

Infection in your homebrew can happen when bacteria or contaminated yeast is introduced into the batch. Once introduced, they compete with your yeast strain for the sugars available, often leading to a bad taste or off-flavors. The main reason infection occurs is due to improper sanitation.

Infected homebrew can taste like many different things depending on the type of bacteria that caused the infection. Tastes can range from sour and vinegar to buttery. Some of the worst infected homebrew can even taste like vomit. 

These off-flavors occur because the bacteria can thrive in homebrew due to the availability of sugar. Just as yeast consumes sugar to produce alcohol, bacteria can consume sugar to develop. 

Depending on the specific flavor you are tasting in your homebrew, it is possible to determine what kind of infection or bacteria you have on your hands and whether your brew can be salvaged. 

Fun Fact: In extremely high quantities, sugar can act as a preservative that prevents bacteria from growing. This is due to accelerated osmosis, which prevents the bacteria from retaining water. Dumping a ton of sugar into your homebrew may not be the smartest idea though!

Can infected beer taste good?

Despite the negative terminology, there are instances when an infected beer can taste pretty good. Depending on the flavor notes the infection creates, it can enhance the brew and make it even tastier

Certain flavors caused by infection, such as tart or sour, can taste good in beer and become the most desirable outcome for homebrewers. This has led to a practice of intentionally infecting beer which differs from accidental infection resulting from poor sanitation or improper storage. 

If your homebrew beer is infected but tastes good, feel free to enjoy it! The harmful infections will always taste terrible. 

Can you drink infected homebrew?

Infected beer is not likely to make you sick. However, it is possible

The bacteria that may enter your homebrew due to improper sanitation are not likely to cause you any physical harm if consumed. The exception to this is if the flavor is particularly bad or you see visible signs of mold in your beer. If that is the case, drinking it could make you sick. Discard the beer and thoroughly clean and sanitize all your brewing components.

The most common place you will see mold development would be on the top of the beer. In that case, you can skim the mold off; if you see mold throughout your homebrew, it’s sadly time to dump it. 

Luckily, the development of harmful bacteria and mold is very rare. This is because the environment of beer cannot sustain them due to the presence of alcohol. 

What does infected beer smell like?

Smell combined with taste can be very useful in identifying what went wrong in your homebrew beer, which in turn can help identify if your brew can be salvaged.

Depending on the smell your homebrew is putting off, it is possible to determine what sort of infection you are dealing with:

  • Butter – Infection of the yeast, issues with oxygenation
  • Skunk – Cell breakdown due to UV light exposure
  • Must – Can be caused by mold present on the yeast during storage
  • Vomit – Bacteria produced when the brew is spoiled
  • Vinegar – Bacteria infection or wild yeast infection

How do you know if your homebrew is infected?

In addition to the off-flavors your homebrew might produce when infected, there are other signs to look out for to know if your homebrew is infected. 

Visual indicators alongside bad taste and smells are the easiest way to determine if your homebrew is infected. The appearance of white build-up on the top of the brew, mold, or intense discoloring can all indicate infection. Often this build-up is called pellicles, which can vary in size and shape. 

Pellicles are formed when Brettanomyces and various lactic acid bacteria are present in the homebrew. These bacteria can reproduce anaerobically (without oxygen), making them perfect for the airtight storage we use when homebrewing beer. 

These are not the only type of bacteria that can infect your homebrew, though. 

What kind of bacteria infect homebrew?

There are a few different types of bacteria that can infect your homebrew beer.

Here is a quick list and description of the most common homebrew bacterial infections:

  • Lactobacillus – Often described as a ‘good’ bacteria, typically present in fermentation and found in the gut naturally.
  • Pediococcus – A lactic acid bacteria that can live without oxygen and can spoil alcohols such as beer and wine.
  • Brettanomyces – A wild yeast that can negatively impact the flavor and smell of your beer.

These are the most common bacteria found in beer, and all result from improper sanitation in your equipment. If you notice your homebrews are consistently getting infected, be sure to replace any equipment that has been overtly contaminated to prevent further infections. 

What should you do with infected beer?

Depending on the type of bacteria and how quickly you catch the infection, you can do a couple of things with infected beer. 

If your homebrew checks all the boxes for infection, you now have the choice to dump or salvage your beer. If you catch the infection early enough and it is not a harmful bacteria, you can adjust the ingredients and skim any infection off the top of your beer. However, if severe mold has developed and the entire batch smells of vomit – it’s time to dump.

Dumping does not mean you have to pour all your hard work down the drain. Several methods of disposing of infected beer can still benefit you, such as creating fertilizer for your garden. 

For more useful ways of disposing of your infected homebrew without wasting it, check out this resource