Yeast-derived flavors are present in all beers, but a strong yeasty flavor can indicate an issue in your brewing process.
Yeasty off-flavor commonly occurs in young (“green”) beers. Maturing your beer for longer is often the most common solution. Other factors include pitching inviable yeast or stressing the yeast, which may cause autolysis. Alternatively, the issue could be that your beer rested too long on the yeast cake, or was improperly separated.
Start by properly cleaning and sanitizing your brewing equipment, especially the fermenter. After brewing your wort, pitch viable yeast at the proper quantity. Take care of your yeast to avoid yeast autolysis or yeast bite. After waiting the recommended fermentation time, check the gravity of your beer to ensure completion. Separate your brew carefully from the yeast cake, without stirring up the trub.
Why does my homebrew beer taste yeasty?
Yeast is the primary component in your beer, so some taste of it is unavoidable. When your beer tastes too yeasty, you may have made a mistake in the process. Some beers, like English ales, are characterized by ester from yeast. While others, like lagers, should have little yeast flavor.
Without cleaning and santizing your fermenter, you may overlook leftover yeast caked inside. This excess can interfere with your freshly pitched yeast, causing yeasty or other off-flavors.
The most common reason for yeasty beer is incomplete fermentation. In other words, your beer is still too young. Yeast cells settle in your homebrew at different rates, depending on the strain. Alternatively, your beer may be “overripe,” so to say, if it sits too long on a yeast cake after fermentation.
Take care to ensure the proper environment for your strain of yeast. Stressed yeast can cause autolysis, resulting in improper fermentation and yeasty off-flavor.
What is yeast bite?
According to Drayman’s Brewery and Distillery, yeast autolysis (or “yeast bite”) occurs when yeast cells rupture, causing undesirable off-flavors to “leak out.” This can result in an excess of yeasty flavor in your finished beer. There are a number of reasons that cause yeast autolysis:
|Unhealthy yeast is more likely to rupture during fermentation when exposed to stressors, such as overly hot or cold temperatures.|
|In the same vein, older yeast cells have weaker membranes, therefore more likely to rupture.|
|In terms of stressors, sudden changes in temperature can “shock” healthy yeast cells, causing some to lyse.|
|Beer stored with yeast for too long can cause the inactive yeast to lyse. This includes young beer before secondary fermentation and completed beer with too much residual yeast.|
|Poor storage condition of cropped yeast.|
Fun fact on (intentional) autolysis:
Did you know that autolysates can taste good? (Just not in your beer.)
For instance, Marmite is a savory spread made from yeast extract. It was invented in 1902 by Justus von Liebig, a German scientist, from brewers’ leftover yeast. Originally, Bass Brewery provided the yeast for Marmite. And it’s nutritious! Marmite contains B vitamins, including niacin, riboflavin and thiamine, and several vitamins.
How do you get rid of yeast taste in homebrew?
As yeast is a primary component in brewing beer, this question challenges a simple answer. All beers have yeast-derived flavor, but a specifically yeasty flavor is not present in all.
For instance, esters are common yeast-derived flavors, which tend to taste fruity. For instance, isoamyl acetate tastes like banana and ethyl caprylate tastes like apple or pear. Ester flavors occur during fermentation, so they are directly impacted by temperature and yeast strain.
There are also phenols, which occur from both yeast and other ingredients, like hops and malt, which contain tannins. The prominent flavor of Hefeweizen, for instance, is results from the interaction of yeast with ferulic acid, found in barley.
How do you reduce the yeast taste in your beer?
If your beer tastes too strongly of yeast, it may be too young, which means that it has not yet matured. In this case, you should store it for longer in a cool, dark place. Over time, the yeast flocculates naturally.
Some brewers choose to cold crash their beer, to encourage the yeast to flocculate. The process involves rapidly decreasing the temperature of your brew, causing the yeast (and other sediments) to settle faster. An effective temperature should be near-freezing, but not quite. (We don’t want a beer popsicle!)
The most common method is simply to place your fermented brew in a fridge. (Check first that fermentation is complete!) The resulting beer looks and tastes cleaner.
How to prevent homebrew from having a yeast taste
Clean your fermenter thoroughly
Cleaning and santizing your brewing equipment are vital steps in brewing your beer. I understand that you’re eager to start, but without preparing properly, you may just spoil your brew. Keep in mind that cleaning and sanitizing are separate steps. Cleaners remove inorganic materials from surfaces, while sanitizers remove the organic leftovers, such as bacteria.
Before starting a new batch, be sure to complete both steps. There may be leftover yeast at the bottom of your fermenter, which would interfere with the freshly pitched yeast.
Let your beer mature for longer
During fermentation, the yeast converts the sugar in your wort into alcohol and carbon dioxide. Fermentation can take from a couple of weeks to a couple of months, depending on the type of beer. (See my article on fermentation times.) Don’t worry if it does not start immediately, the yeast may need up to 48 hours to activate.
When primary fermentation is complete, most of the yeast should settle at the bottom of your fermenter, leaving young, or “green” beer. This beer needs to complete a secondary fermentation in another vessel, such as a bottle or a secondary fermenter. If you taste your beer prematurely, it will probably taste yeasty, indicating that the fermentation process is incomplete.
Pitch fresh, viable yeast
Have you ever tried that apple-onion challenge? Without sight or smell, many cannot differentiate between the two.
Sometimes, your homebrew may taste alright, but smell too strongly of yeast. Smell directly influences taste, too much of a yeasty aroma can promote that yeasty off-flavor. Less vital or mutated yeasts can promote a strong yeasty or sulphurous smell. Likewise, beer that contains inviable yeast sediment for too long can cause yeast autolysis.
To check if your yeast is viable, make a small starter before brewing day. If it does not begin fermenting by the next day, replace it. The date on the package is also a good indication.
It is possible to reuse the remaining yeast cake (sometimes called “slurry”) for your next batch, but can be tricky. There are several factors to consider, such as the style, hops, and gravity of the previous brew. For those interested in learning more, take a look at this discussion to start.
Avoiding yeast autolysis or yeast bite
Yeast is a living organism, influenced by its environment, which is your wort. Before beer, there is fermentation, which is contingent on the yeast. For your yeast to perform properly, you must provide it with the correct nutrients and temperature. There are a number of stress factors, which can cause yeast autolysis.
Keep these in mind, in order to avoid them:
|Inadequate temperature control during fermentation or storage. Abide by the temperature range recommended for your yeast strain.|
|Nitrogen starvation. This should not be an issue if you brew your wort properly. Malt contains carbon and nitrogen, which the yeast needs.|
|Vitamin or mineral deficiencies. These are normally found in malt and water, namely traces of calcium, magnesium, zinc, phosphate and sulfate. Hard water is generally better than soft water for brewing.|
All-malt beer has the necessary nutrients that yeast requires, but all-extract beers may cause some problems. These types often have insufficient free amino nitrogen for the yeast to grow. If you use malt extract in a starter, you may want to add some nutrients to ensure the right environment, in which your yeast will thrive.
Separate your homebrew from the yeast sediment
To avoid the problem of excess yeast or worse, yeast autolysis, separate your beer at the right time. Pour your young beer carefully into the secondary vessel, without stirring up the trub. A small amount of yeast is necessary for the secondary fermentation, but leave the rest at the bottom.
To check if your yeast is inactive, monitor the gravity of your wort at the end of the recommended fermentation time. If the gravity reduces, it means that active yeast is still processing sugars. If the recipe requires longer fermentation, you may want to resuspend your yeast by gently swirling. (See my article on fermentation time .)
If the gravity reading does not change over three days, your primary fermentation is complete. Transfer your beer, do not let it sit on the yeast cake for too long.
Fermenting it Over
A yeasty flavor is appropriate in a number of beers, but it should not remind you of Marmite. With the discussion here in mind, you should be set for avoiding that yeasty off-flavor in your new brew.
If you would like to dig deeper into yeast science, I recommend Yeast: The Practical Guide to Beer Fermentation, by Chris White.