Do Coffee Beans Go Bad?
I’m the kind of coffee fiend who usually makes the mistake of brewing more than I can consume in one sitting. Hours later, though, after a shocking sip of what was perfectly brewed coffee, this thought comes to mind:
Do coffee beans go bad and why does coffee spoil?
If you’ve been ‘surprised’ by your brew going rancid, or your beans not living up to your super high coffee standards - and wondered just how long coffee beans last - read on and discover how your most favorite thing in the world can ‘go bad’, and how to deal with it:
It Starts with the Beans
So what was your coffee before it became that deep, dark cup of goodness? The journey starts way back from its raw state, where technically, the ‘beans’ are the seeds of the coffee cherry. As is, these little green beans are not fit for grinding or brewing.
They first have to go through the roasting process (1), which subjects them to very high temperatures, bringing out the caffeol that produces that distinct coffee aroma and flavor. Right after roasting is when your coffee beans are considered to be at their ‘freshest’. From this point forward, the roasted beans face their greatest enemies in the environment - oxygen/air, moisture, heat, and light.
How Long do Coffee Beans Stay Fresh?
Good question - and we’re happy to answer that for you. The fact of the matter is, not that long, unless you take the precautions we’re about to arm you with. You see, the delicate compounds in coffee quickly react to the elements mentioned above and hasten the process called oxidation, which affects the concentration of important coffee oils in the beans.
The longer the newly-roasted beans are exposed to the air, the faster they oxidize, sacrificing their taste (adding that unwanted bitterness) and aroma. This is what roasters try to avoid by packing and delivering their beans as soon as possible after roasting.
Ask any coffee expert how long coffee beans stay fresh and they will tell you that freshly-roasted beans should always be consumed within a week to one month after roasting, to make the most of its quality. After that, it’s kinda hit and miss!
The Art of Keeping Roasted Beans Fresh
Now that you’re aware that newly-roasted beans can lose their freshness relatively quickly, it is important that you also know you’re not entirely helpless. You can begin by taking more conscious efforts in properly storing coffee beans.
There are 3 important factors to consider in storing your coffee.
First and foremost, you want to keep it away from exposure to air or oxygen. Packaging is key. The most convenient packaging to use, and something you will most likely find in supermarkets and some coffee shops, are valved packs.
Valved packets of coffee beans are equipped with a specially designed hole that allows the release of carbon dioxide, without letting any air in that can make the beans go stale. These are not meant for long-term storage however, so always check on the roasting date stamped on the pack.
Another storage option are airtight, opaque jars. While mason jars can beautifully showcase your shiny brown coffee beans, they let in too much light, which can also affect the quality of your coffee.
Instead of clear containers, you may want to go for especially-designed ones called coffee vaults. which are typically made of stainless steel and secured with lids to keep the vaults airtight.
Once you have a good-sized, airtight container, it is important to avoid exposing it to high-temperature or hot environments. This includes areas like your windowsill, the cupboard near your stove, or the counter space beside your toaster.
Heat can accelerate the non-enzymatic browning and degradation of the aromatic properties of your beans, which also makes them go stale faster (2).
"The loss of carbon dioxide from coffee occurs due to diffusion forces, which move molecules because of differences in pressure and/or gradients of molecule concentrations. When coffee is ground, the porosity and surface-to-volume ratio increase, which accelerates degassing and staling." - Emma Sage, SCAA
A common storage question often gets asked: can you freeze coffee to keep it fresh? We answer that question here, but here's the short version:
Moisture figures into the equation when you place it in cold places, like your freezer. Even if it’s sealed tight in a quality coffee vault, taking it out, opening it, and returning it in the freezer, can cause temperature changes that allow condensation to form on the beans.
If freezing is at all necessary, we suggest you set aside the coffee beans you do not plan to use or grind for at least a week, and make sure to place your beans in a guaranteed airtight container. You can also divide them into small portions, so you only unfreeze what you need.
This video gives a great insight of how to store your precious, freshly-roasted coffee beans.
Do Coffee Grounds go Bad?
You’ve taken every care to choose amazing beans and store them properly to secure that heavenly brew that makes makes waking up worthwhile. The next stop in your coffee beans’ journey takes place in a grinder. This is where you process your beans to achieve the size and texture that’s right for the brewing method of your choice.
But, how much do you grind and how long do you keep ground coffee before you use it? This raises the question: do coffee grounds go bad? Coffee experts suggest that you use ground coffee for brewing within thirty minutes from grinding.
This is because the grinding process further hastens oxidation in your coffee (3), which in turn reduces the freshness and strength of its flavors. If immediate brewing is not possible, store your ground coffee as you would your freshly-roasted beans.
And in case you are curious, yes, your brewed coffee can go stale too - even faster than whole beans and ground coffee! This is because water helps release more solubles, causing coffee to oxidize at an even quicker, accelerated rate (4).
Keeping your brew in a thermos may keep it hot and ‘fresh’ for a bit longer, but you’ll already notice a change in taste no more than an hour later - it becomes a bit more sour and a little bitter. If you want more fresh coffee to consume, brew only as needed.
There you have it, you’ve learned that your coffee - from beans to brew - can indeed spoil, as its oils, acids, and other chemicals can succumb and react to its natural ‘enemies’ in the environment. Just like any other organic food item, coffee requires proper storage and handling so you can maximize its freshness, flavor and taste.
Keeping it Fresh:
- Always purchase freshly-roasted beans.
- Be ready with proper storage containers for your coffee.
- Keep your stored coffee away from oxygen, heat, and moisture.
- Grind only the amount you need for your brew.
- Brew only what you can consume for the next hour.
Now that you know the answer to the question 'does coffee go bad?' is YES - it’s no longer scary, because you've just learnt how to keep it fresher, for longer. You'll never have to worry about a stale and bitter brew. Keep it fresh and you'll keep yourself and your guests happy.
Frequently Asked Questions
How long can you keep coffee beans?
You can keep coffee beans for about a month, as long as you store them properly. Use an airtight, lightproof container and store them away from heat or moisture. Buy only as much as you expect to drink in this time, and buy the freshest and most recently roasted coffee you can.
How do you know if coffee beans are bad?
How do you know if coffee beans are bad: smell them. Stale coffee beans have a dull, lifeless, and even rancid or musty aroma. If the beans smell musty, the brewed coffee will taste that way.
Are old coffee beans safe to drink?
Yes, old coffee beans are safe to drink. They won’t taste as good as fresh beans, and they will probably have a musty or even rancid aroma, but they will not make you sick.
- 10 Steps from Seed to Cup. (n.d.). Retrieved May 23, 2019, from http://www.ncausa.org/about-coffee/10-steps-from-seed-to-cup
- Sage, E. (2012, February 15). What is the Shelf Life of Roasted Coffee? A Literature Review on Coffee Staling. Retrieved May 23, 2019, from https://scanews.coffee/2012/02/15/what-is-the-shelf-life-of-roasted-coffee-a-literature-review-on-coffee-staling/
- Smrke, S., Wellinger, M., Suzuki, T., Balsiger, F., Opitz, S. E., & Yeretzian, C. (2017, November 1). Time-Resolved Gravimetric Method To Assess Degassing of Roasted Coffee. Retrieved May 23, 2019, from https://pubs.acs.org/doi/full/10.1021/acs.jafc.7b03310
- Calderone, J. (2015, September 28). Why Coffee Gets Stale. Retrieved May 23, 2019, from https://www.businessinsider.com/why-coffee-gets-stale-when-sitting-out-oxygenation-2015-9