If you find a long-forgotten packet of beer yeast in the back of your refrigerator, you may be questioning if it’s still viable to use in your next batch of homebrew. Does beer yeast have an expiration date?
Most commercially available dry beer yeast has an expiration date of between 1-3 years while liquid yeasts have a printed date of between 3-6 months but both can sometimes be used past this date. Canned yeast starters do not need to be refrigerated and have a shelf life of about a year.
Read on to learn about yeast, how to store it, and how to ensure that it’s healthy enough to brew with.
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Does beer yeast ever expire?
If you’re not sure of the age of your yeast, there are ways to determine if it’s still usable, which will vary depending on the type of yeast. There are also ways to extend its shelf life, such as using a yeast starter.
Unlike most perishable food, yeast won’t necessarily “go bad” in the sense that it will spoil, rot, or become dangerous to consume. Typically, commercially available beer yeast will come with a recommended use-by, best-by, or expiration date.
As a living thing it will, however, perish eventually if it’s not properly cared for. Commercially available beer yeast is packaged to survive or lay dormant for a set amount of time, determined by the manufacturer.
Does beer yeast have an expiration date?
Yes, just about any beer yeast that you buy at a homebrew store or from an online homebrew supply will have some sort of expiration date printed on it.
Each yeast manufacturer determines that date based on the type of yeast and the way it’s packaged. This date is usually printed clearly somewhere on the outside of the yeast package and is usually consistent across an entire brand of yeast.
Does beer yeast have a best-by date?
Some commercial yeast may say “best by date” instead of “expiration date”. This is often used in beer yeast as well as other foods that don’t spoil but lose freshness or potency over time.
The use of a “best by” date implies it’s not necessarily dangerous to consume or use the product after that date, it just may not be as effective.
The date on beer yeast may be expressed as a “best by” date. Regardless of whether the date on your yeast is listed as an expiration or a best by date, you should try to use the yeast before that date.
The farther past the recommended date, the less likely the yeast is to be alive and viable.
Can you use expired beer yeast?
So what happens if you have a package or two of expired beer yeast on your hands? Is there anything that can be done?
Depending on what type of yeast you have, there are steps you can take to check its viability. The good news is, no matter what the expiration date on the package says, if you’re able to confirm yeast activity you can go ahead and use it in your next batch of homebrew. It’s perfectly safe to use.
Some liquid yeast packets, like those from the manufacturer Wyeast, have “smack pack” technology. Essentially, by smacking the package of yeast with your hand, you break open a smaller internal packet of yeast nutrients.
The yeast begins to eat these immediately and release CO2, causing the package to swell. The faster the package swells, the healthier the yeast. In addition to the swelling package, you should also be able to hear the yeast bubbling inside if you hold the package up to your ear.
If you’re using another type of yeast without this built-in test system, the best thing to do to test its viability is to “proof” it, similarly to how you may proof baker’s yeast.
To test your yeast, whether expired or not, follow these steps:
How to Proof Beer Yeast to Test if It’s Still Good
- Boil 1 cup water
- Remove water from heat and stir in 1 teaspoon table sugar.
- Cool sugar water to approximately room temperature. NOTE: be sure to keep it covered as it cools to avoid contamination
- Pour in 1 teaspoon beer yeast to the cooled sugar water and give it a bit of a swirl (Note: do not over-agitate.)
- Watch for foaming and other activity.
If your yeast is still healthy, you’ll start to see foaming or bubbles within 20 minutes or so as the yeast starts to eat the sugar. This should be quite clear and over time, the foam should cover the surface of the liquid.
Because of the limited sample size of the proved yeast, it will eventually stop being active. This is totally normal and not a cause for concern.
If you don’t see foam or bubbles after an hour, your yeast is likely dead and not salvageable. In this case, the liquid would look opaque as well as “flat” like tap water (as opposed to carbonated like beer). Avoid the temptation to use it, you’ll only waste a batch of perfectly good beer!
Discard it and start with a fresh batch of yeast.
How long does beer yeast typically last?
Most commercial beer yeast will have an expiration or best by date printed on it that’s established by the manufacturer. They will establish this date based on the type of yeast and the way they package it.
Normally, dry yeast will have a shelf life of between 1-3 years while liquid yeast will carry a shelf life of between 3-6 months. In most cases, both dry and liquid yeast will last longer than the printed expiration date with proper care.
In short, there is no set life span for yeast. As long as the yeast is well cared for, it can last for years. Different types of yeast last for different amounts of time.
How long does dry beer yeast last?
Dry beer yeast has a much longer shelf life than its liquid counterparts.
Depending on the brand and type of yeast, most dry yeast has a shelf life of 1-3 years.
For a long time, dry beer yeast got a bad rap.
It was commonly assumed that liquid yeast was better for brewing beer than dry yeast. Nowadays, both types of yeast have their advantages. In addition to its much longer shelf life, dry yeast is typically more affordable than liquid yeast. It also is more temperature-tolerant, so it does not always need to be refrigerated.
How long does liquid beer yeast last?
Liquid beer yeast is a favorite of many homebrewers as it tends to be very fresh. That freshness also means that its quality degrades quickly.
Liquid beer yeast’s shelf life usually is 3-6 months. During that time, it must be kept refrigerated as the yeast is alive and active.
The primary benefit of liquid beer yeast is the vast variety of strains available on the market. This allows homebrewers to get very specific with their recipes and use ingredients that reach the quality of commercial brewing companies.
How long do canned yeast starters last?
A fresh new innovation on the homebrewing scene is canned yeast starters. Canned yeast starters like this one from Propper allow homebrewers to create a yeast starter without having to boil wort. These cans of condensed wort do not need to be refrigerated and have a shelf life of about one year.
It’s important to note that these products are not yeast themselves, they’re basically supercharged wort that are designed to get healthy yeast working and thriving quickly. This means no boiling a mini-batch of wort, just combining yeast with the can of yeast starter and allowing it to proof for 24 hours.
How to make beer yeast last longer
The key to getting the most out of your yeast is making sure to store it properly. Because yeast is a living thing, it needs to be cared for in order to thrive.
Different types of yeast require different storage conditions.
In general, all types of yeast should be stored in a cool, dry, dark place. Heat can kill yeast so keeping it cool is essential.
Dry beer yeast
Dry beer yeast is the easiest type of yeast to store. Though it can be kept at room temperature for a few days (for example, during shipping if you order it online), it’s best to keep it in the refrigerator. Excessive heat can neutralize some or all of the yeast.
A lot of dry beer yeast is pre-portioned into individual envelopes designed for a 5 gallon batch of homebrew. If you buy it in a larger package, make sure to store unused yeast in the refrigerator in an airtight container.
Liquid beer yeast
Liquid beer yeast is very temperature-sensitive and should be refrigerated consistently. If you order liquid beer yeast online, be sure to confirm they’ll be shipping it on cold packs.
Once you get your liquid beer yeast home, try to keep it in the refrigerator door. If liquid yeast ends up stuck in the back of your fridge where the temperature drops, it could freeze, neutralizing your yeast.
Canned yeast starter
Canned yeast starter is shelf-stable and designed to be stored at room temperature for up to one year. This concentrated wort can be mixed with water to create an ideal environment for yeast to activate.
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