Do coffee beans go bad?
First off - do coffee beans ever go bad? At first glance, visually, it might seem like coffee beans never go bad, but that isn’t actually the case. While coffee beans may not mold like bread or rot like fruit, that doesn’t mean that old coffee will provide you with a good experience or a good flavor.
When preparing coffee, it’s all about freshness. Freshness is the key to great coffee, which is why it’s so important to use fresh coffee beans that have been protected from exposure to air, light, and heat. The freshness of your coffee is hugely impactful on flavor and aroma and directly impacts your enjoyment of a cup. Let's take a look at these factors and how to avoid them.
How long does coffee last?
Coffee beans have a lifespan that varies with their roasting and grind status:
- Green coffee (industry jargon for harvested beans that have yet to be roasted) can last for up to a year if stored properly - away from light, heat, and air. If you're purchasing green coffee beans for home roasting, make sure to store them properly before you roast, just like you would with roasted coffee.
- Once green coffee beans are roasted, the clock is ticking. Try to consume fresh-roasted beans within 1-2 weeks following the roast date to maximize cup quality.
- Grinding the coffee beans further speeds things up - the grinding process increases the surface area of the coffee, which in turn increases exposure to the air. Ground coffee will quickly lose flavor and aroma after grinding. So whenever possible, brew as soon as possible after grinding.
How can you tell when coffee beans are “old” ?
Oxidation begins when roasted coffee beans are first exposed to the air. We can slow this process with best practices for storage, but never stop it entirely. Best practices for storage slow the oxidation process, so you can consume the coffee at its peak.
You may notice old coffee is lacking in flavor and aroma, or worse, has a distinct musty smell. Coffee can also taste undesirably bitter as it ages.
To evaluate coffee beans, use your eyes, nose, and sense of touch:
- the roasting process encourages natural oils within coffee beans to rise to the surface; so fresh beans should be shiny.
- If the beans are dull and the grounds feel dry, the coffee might be old.
- Check the roast date on the bag - then you’ll know exactly how much time has passed since roasting and when to consume it.
What is de-gassing, and why is it important to coffee?
After roasting is complete, the de-gassing process (during which carbon dioxide is released from roasted beans) starts immediately, and can take several days. It’s important to allow carbon dioxide to escape during this process, but at the same time, we want to keep oxygen away from the fresh-roasted coffee, to prevent oxidation. See below for more information on the special one-way valves on coffee bags that allow de-gassing.
Fresh coffee beans may need some time for the de-gassing process to complete after roasting before reaching their best. The de-gassing process could take from a couple days to a week, depending on the specific beans. Coffee is a living, breathing thing - so get in tune by experimenting. Your specific coffee might be best immediately after roasting, after a few days, or a week.
Check the “roasted on” date on the bag so you can allow some time before grinding and brewing if desired. A few days to a week is ideal depending on the specific coffee - it’s OK to experiment and find out what suits your tastes! For fresh-roasted coffee shipped to your home or office, the time in transit while the coffee is with the shipping carrier is typically enough time to allow the de-gassing process to complete before the coffee arrives to you.
How to store coffee for best results
It’s OK to leave coffee beans in their non-resealable store packaging for a short time, as long as it remains sealed. Remember, freshness is key to great coffee! Once you cut open the bag and leave it open, you’re allowing all the important gasses to escape.
Recall that oxidation begins when newly-roasted beans are exposed to the air. Some oxidation is unavoidable, but you need to take preventive measures to slow it down, ensuring your coffee can last longer. Think of that bag of chips that you left open, the next day they are stale and flat, just like your coffee will be if you leave it exposed.
Once opened, transfer beans to an airtight container if they won’t be used immediately. If your bag is resealable with a little zipper on top, you can also leave it in the bag, but still store it in a cool, dry place away from direct sunlight!
Once you open the coffee:
- Don’t grind until you're ready to brew
- Use an airtight container to store any unused cofffee
- Put the container in a cool, dry place
- Avoid light, heat, and moisture
- Re-seal the bag with the "zipper" closure, if it has one
How much coffee should you buy and store?
For the absolute best cup, buy and store only what you can use in the short term - like 1-2 weeks. Again, think of fresh-roasted coffee beans like a bag of chips, they should be used in the same time frame once opened. This is a good reason to buy smaller bags of fresh-roasted beans as you need them, instead of purchasing and storing larger bags that will take months to consume.
While it can be tempting to “stock up,” (since going to the store frequently is a hassle) - don’t buy a larger bag just to minimize trips. Subscription services are ideal for putting delivery of small quantities of fresh-roasted beans on autopilot - no last-minute trips to the store.
Where to store your coffee beans
It’s important to find a great place to store coffee beans in your home or office. Heat speeds up the oxidation process, which in turn affects the flavor and aroma of your coffee. Some oxidation is unavoidable, but take care not to needlessly accelerate it with careless storage.
Coffee is best stored in a cool, dry place away from moisture, heat, and light sources:
- Store coffee away from the stove.
- Store coffee away from windows. Even the light from a window on a warm afternoon can be too much - a dark pantry is ideal.
- Keep coffee away from moisture sources.
What about the storage container? Opaque or transparent?
An opaque container is a better choice for preserving coffee aroma and flavor profiles. This is the same reason most craft beer is shipped in dark-colored bottles, by the way - to protect it from light before it’s consumed.
While there may not be any hard data specifically comparing opaque and transparent containers, we’d encourage you to think about fresh-roasted coffee just like fresh produce - it has a shelf life and a window after it’s harvested during which it will taste best. Using an opaque container and storing the coffee away from light sources can help extend that window.
When is the optimal time to grind coffee beans?
Specialty coffee roasters want you to have the best possible cup. While some drinkers might choose to grind all the beans at once, we’d encourage you to grind only what you need, while storing any remaining beans in an airtight container.
- Grind immediately before brewing. The grinding process increases surface area, which in turn speeds up the oxidation process. Don’t unnecessarily speed it up by grinding more beans than you need.
- While it’s best to grind at home/office using a high-quality coffee grinder, that may not be realistic for everyone due to noise, space, or time constraints. Specialty roasters like Klatch Coffee offer a courtesy grind (on some coffees) to customer specifications based on the planned brewing method (fine, medium, coarse, and so on.)
- If you buy pre-ground coffee for convenience, consider buying smaller bags that you replace more frequently to minimize the time between the grinding and brewing process.
Why do some coffee bags contain a valve?
You may have noticed some specialty coffee roasters use bags with special one-way valves. Those valves serve a unique purpose - allowing carbon dioxide (released as part of the de-gassing process) to escape, while preventing oxygen from entering at the same time.
At Klatch Coffee, we roast and bag the same day, which helps guarantee that our customers receive only the freshest roasted coffee possible. The one-way valve on our resealable bags allows de-gassing to occur while the coffee is in transit with the shipping carrier, so no additional waiting is needed once your coffee arrives - you can grind and brew it immediately.
What about freezing?
Freezing coffee is often proposed as a low-cost alternative for storage. It’s understandable - you want your specialty coffee to last. But be aware - when you thaw the beans, they can start absorbing moisture from condensation, which can ruin the crucial oils that hold the flavor of your beans.
For this reason, if you choose to freeze coffee, you should use it all immediately after taking it out of the freezer. If that doesn’t work for your usage habits, larger batches can be frozen by pre-portioning them into smaller individual batches, each of which can be independently thawed when needed.
What everyone should know about storing coffee
We want you to be able to enjoy the best possible cup of coffee, which is consistent and repeatable from day to day, but don’t overthink it - the best “trick” of all is simply implementing the well-known, best practices for coffee storage and sticking to them!
To make sure you can appreciate the distinct aromas and flavors that were carefully curated by the roaster, stick to the core principles:
- Purchase fresh-roasted whole bean coffee whenever possible
- Buy in the quantities you plan to consume in the short term
- Don’t grind the coffee until you’re ready to brew it
- Store any unused coffee in an airtight container
- Keep the container in a cool, dry place away from light, heat, and moisture
To make sure you are able to enjoy and appreciate the nuances of specialty coffee, nail those basics - you’ll be ahead of the game and well on your way to enjoying a better cup of coffee!
