Have you ever wondered if coffee can go bad, like most other foods?
We only consume small amounts of actual, ground coffee every day. Other than that, coffee sits unused for longer periods of time than most other foods that we consume every day. Sometimes months! So the question needs to be asked: Does it go bad?
Well, the answer isn’t simple. It can go stale which is one thing but, since it has been roasted and thus doesn’t have any water in it, it doesn’t rot or “go bad”. Because it’s completely dry, it lasts longer without attracting bacteria that are responsible for food going bad.
To better understand what’s going on here, we need to take a look first at what a coffee bean is and how it does it go from farm to cup.
What is a Coffee Bean?
A bush named coffea is grown. With the right amount of love and nutrients, it’ll give cherries in a year or two. These cherries are small, round; they are of a yellow color which turns a vibrant red when ripe. And it is then that they are picked – almost always by hand.
After they are picked, they are left to dry out in the sun. There are also other processes, but sun-drying is the most widely used because it yields a better flavor. Then, the fruit is carefully removed to reveal the seeds inside- they are green and come in pairs. These are the coffee beans, which are actually seeds!
Because of the stickiness of the coffee berry, a good wash is in order. This removes loose pieces of fruit as well as a thin membrane that forms on the surface of the bean that is neither fruit nor bean. Once this is done, the beans undergo a slight period of fermentation.
At this point, the green beans are naturally dried and shipped out to the roasting facility.
Seeds, usually, are quite resistant to going bad. This is because they don’t contain as much water- they are mostly fiber and fat. This protects them from the elements- so coffee beans, even when green, are quite resistant.
Green beans travel, inside cloth bags, hundreds of miles from farm to a shipping port. From there, they travel across countries or continents to get to the roasting facility. And throughout this process, 99% of all green beans are still in good condition.
Roasting consists of technically baking the beans. This will remove what little water they had and now they are even more resistant to going bad.
After roasting, coffee beans are usually packaged in sealed bags. And this is key: the bags are never transparent and are made of resistant material- they are certainly not just a bit of plastic, but good material.
Bad or Stale? Is it the Same?
We’ve established that coffee can’t really go bad because there isn’t much water in coffee beans to begin with. You’ll never get sick from drinking coffee made from bad beans, nor never open a bag to find a rotten stink.
What can happen, however, is that the oils in the beans go rancid. This gives it both a sour smell as well as a distinct sour taste that isn’t pleasant like the usual acidity in coffee. It’s also possible that coffee becomes bland in taste, or that it tastes like something it shouldn’t – such as rubber, or something else.
Because coffee is very absorbent, whenever the seal is compromised in packages, it’s as good as gone. It will take in smells from outside and soak them in. Some of them can be very, very unpleasant.
Alternatively, if coffee is exposed to too much heat or warm for prolonged periods of time, the oils will go rancid and ruin your coffee.
It is absolutely possible that you’ve had stale coffee before. It’s hard to tell the difference because it could easily just be a bad batch. Sometimes, we even convince ourselves we did something wrong during the brewing process.
How can I Prevent my Coffee From Going bad?
Four things: humidity, oxygen, sunlight, and temperature. These four things are what compromises the integrity of our coffee. If we learn how to properly control these four things when we store coffee, we can keep our fresh and tasty for much longer than you think.
- Humidity is the most obvious one. It attracts bacteria and mold. Since coffee is usually stored in dark places, mold is one of our primary concerns here. It can spread quickly if we’re not careful. Keep coffee stored somewhere dry, inside a seal container. Whenever you need to use it, close the container as soon as you’re done using it because of the humidity in the air.
- Oxygen is very dangerous. It will oxidize the fats in coffee and turn them rancid. This is why we need containers that are very effective at keeping oxygen out, and why we can’t leave our coffee hanging around in the kitchen after we’ve used it.
- Sunlight kills the compounds responsible for flavor in coffee. It’s so dangerous that all coffee packaging is as opaque as possible (except for instant coffee containers). Even grinders have tinted glass where the coffee beans go to protect them as long as possible from the sun.
- Temperature exacerbates all three previous factors. If there is some humidity but low/medium temperature, you’re fine. But if it’s warm for too long, it’s a big problem. High temperatures will make bacteria spread faster, it will make oils go rancid twice as fast, and it will kill all aroma and flavor. If nothing else, see that your coffee is guarded from high temperatures. Anything over 95°F is considered high.
Coffee canisters have emerged in recent years and they do a great job at keeping coffee fresh. They don’t let any air in, are opaque, and some of them even have a CO2 valve which lets gas through, but not oxygen. Coffee beans emit CO2 naturally and having an escape valve for it will further protect your beans from unwanted odor.
To put it simply, store your coffee beans in a dark, cool, dry place. Ensure they are in a sealed container and they should stay in great condition for a long while.
Ground Coffee vs. Whole Bean
Another thing to take into account is that ground coffee has a much shorter shelf life than whole beans. Because ground coffee consists of very fine particles, it’s much more vulnerable. They are all exposed to the elements in a way that whole beans aren’t because they are still whole.
By rule of thumb, whole bean coffee lasts anywhere from three to six times longer than ground coffee. Ground coffee can last up to three weeks in good condition after the container’s been opened. Whole beans can last up to six months as long as they are stored properly.
This is why some ground coffee can already be bad as soon as you open it: you don’t know how long it’s been sitting there. It could have been roasted in another country (or even continent) and then shipped to your area. There, it sat in storage for at least a few days. Then, it was put up on the shelves.
In general, it’s a better idea to buy whole bean because of this. Ground coffee is of course much more convenient (not everyone has a grinder), so if you do buy ground coffee we suggest you stick to buying small quantities – and storing them according to what you’ve just read here. You’ll definitely notice a big difference in taste.