What Happens if You Add Too Much Yeast to Beer (Or Can You?)

If you know anything about homebrewing, you know that there are many things that can go wrong during your process. What happens if you add more yeast than the recipe calls for? Is your beer ruined?

When you add too much yeast during the brewing process, chances are good that your beer will be fine. It is difficult to overpitch beer in a way that negatively affects the final product. The extra yeast causes the beer to ferment faster so it may develop less complex flavors or, in extreme cases, cause the beer to develop off-flavors or be dry.

Keep reading to explore the effects of yeast on beer brewing and find out how much yeast is too much in your homebrew.

Can you add too much yeast to your homebrew beer?

Unlike science experiments in those B-horror movies that are best enjoyed with a few drinks, adding more yeast than you meant will not create some unholy abomination. 

In reality, it is difficult to overpitch when homebrewing. Even when you do add more yeast than necessary, it is not considered too much as it may change your beer but shouldn’t ruin it.

Of course, the overpitch may be too much for your individual preferences. If you are aiming for a particular style and use too much yeast, the changes that would introduce may cause the beer to miss the mark. 

It may still be a good beer, however, depending on the severity of the effects.

A good rule of thumb for homebrewing is to pitch a little more than you think you’ll need. Underpitching will have worse effects and is much easier to do.

What happens if you pitch too much yeast in the beer?

With that said, if you do manage to overpitch, you should know what to expect. This way you know what to attribute to overpitching as opposed to other factors.

Overpitching can result in faster fermentation which can, in turn, reduce ester production. It can also lead to a dryer beer. In extreme cases, overpitching can increase the chances for autolysis which results in undesirable off-flavors.

Faster fermentation is the most likely effect when overpitching. Since the yeast cells don’t have to build up to a viable cell count they can begin fermentation much sooner. It is this reduced reproduction that reduces ester production.

This makes the beer cleaner overall which can be beneficial or detrimental depending on the beer style.

Another possible effect is drying out the end product. This doesn’t happen as much and again can be good or bad.

Autolysis can occur as a result of over-pitching. However, it is usually only noticeable in extreme cases. Doubling the pitch rate likely won’t cause noticeable autolysis. You would have to multiply the pitch rate by four or five to have a chance of this.

This process is the main cause for any off-flavors generated by over-pitching.

Beer styles and yeast strains that you do not want to overpitch

While so much of homebrewing is judged by personal taste, there are a few beer styles and yeast strains you should avoid overpitching.

Any beer style that gets most of its flavor from yeast should not be overpitched, including Hefeweizens and Belgian-style Tripels. You should also avoid overpitching ale yeasts such as WLP400.

Overpitching the above styles and strains would be a waste of good yeast. It would ruin the flavors that these beers are known for. Misusing yeast in these cases will be easily apparent. 

Related questions

Now you have the answers relating to the effects of over-pitching. If those answers led to more questions keep reading to see if I have answered them.

Does adding more yeast add more alcohol?

It may seem logical to assume that adding more yeast would increase the final ABV. Unfortunately, this is not the case.

Adding more yeast does not add more alcohol. Yeast consumes sugar to produce alcohol and carbon dioxide. The alcohol content is limited by the amount of sugar in your wort.

However, yeast can only process certain types of sugar. One common example of sugar that yeast can’t ferment is lactose.

Learn more about adding lactose to beer in this article.

What is the best sugar to use for brewing?

Since yeast can process some sugars more easily than others, it is important to know which sugars are best for brewing.

The two best sugars for homebrewing are dextrose and sucrose. These two sugars are 100% fermentable and relatively simple for yeast to consume. 

Yeast usually gets the sugar it needs from the grains, but extra sugar can be used for a variety of purposes. Dextrose and sucrose work very well for many of these purposes.

Does adding more yeast speed up fermentation?

Fermentation is a somewhat complicated process, but it becomes easier to understand when broken down.

Additional yeast can speed up fermentation because fermentation lasts as long as there are available nutrients. More yeast will consume the nutrients quicker.

When yeast is pitched into a wort it goes through a few stages. In general, the more yeast cells there are, the faster fermentation will move on to the next stage. 

Usually, it ends when all of the nutrients in the wort are used up by the yeast, but sometimes it can end early if the yeast flocculates early.

Does adding more yeast make my beer toxic?

Most of the time, homebrew beer is safe because the alcohol content will kill any bacteria. That said, it is possible to make toxic beer.

Luckily, adding yeast is not a factor that can result in toxic beer. In fact, a good yeast pitch can reduce the chances by speeding up fermentation.

This is primarily due to the drop in pH that comes about as sugar is converted into alcohol. The faster this happens, the lower the chance for harmful bacteria. As I have already covered, overpitching will speed up fermentation.

It is still very important to maintain good brewing practices. You should sanitize everything that comes in contact with your beer.

If you use a plastic fermenter, check out this article for how to sanitize it properly!

What does it mean to have different yeast strains?

Yeast does the same basic job no matter the strain. This makes it easy to think that the strains aren’t all that different. 

Yeast strains are different because they all have different characteristics that affect the result. They are all suited to various beer styles based on these characteristics. They include attenuation rate, temp range, flocculation rate, and alcohol tolerance.

The common types of yeast strains are lager, ale, German ale, seasonal, and Belgian ale. They are divided into two categories: ale and lager. The former are top fermenters and have higher temp ranges. The latter are bottom fermenters and have lower temp ranges.

What is overpitching vs. underpitching?

Missing the pitch rate for a brew will either result in underpitching or overpitching. Both will change the fermentation process in their own way.

Overpitching will result in a faster fermentation process. It can change the resulting flavor profile in a couple of ways. Underpitching on the other hand can result in stuck fermentation. It will also affect the flavors, often in worse ways.

The first will always result in beer. It may not be exactly what you wanted to make, but it will be beer. The effects of this are covered above.

The second can still result in beer. However, it can also stop fermenting before completion unless helped along. The effects of not adding enough yeast are usually worse than if you had overpitched.

I’m new at this…what is the best homebrew kit?

If you want to get into home brewing, a kit can be a great way to dip your toe into the water. But which one is the best?

You can find homebrew kits for a plethora of beer styles. A quick look through a homebrew supply store will show you a beer kit for your preferred style. 

Popular homebrew kits include:

Homebrewing has become such a popular hobby that there are kits for nearly every style. There are even homebrew kits for popular macro brewery beers!