Do coffee beans ever go bad?

If you’re looking for a quick answer to this question, then here it is: Yes, coffee beans do go bad.

But this question requires more than a simple ‘yes’ or ‘no’. There are many factors at play that affect the lifespan of a coffee bean.

To explain the how and why of it all, then, keep reading.

A little background: what actually is coffee?

Coffee is commonly thought of as a bean. As consumers, we roast beans, we grind beans, we drink beans. But, like almost every other bean, coffee starts its life growing on a plant, encased in something else: a cherry. And it’s these cherries that give life to the coffee beans we know and love.

As a coffee plant grows, their cherries mature, and when the season is right, coffee farms do what they do best and pick these cherries, harvesting the ‘seed’ or ‘bean’ within.

It’s from this moment that a coffee’s incubation period is over, and its ‘life’ out there in the big wide world begins.

How long does coffee last?

There are many factors that go into answering this section, including to what extent you roast your coffee. It’s not as simple as giving them a squeeze or seeing if they’re brown like a banana.

It also depends on what stage of the lifecycle a coffee bean is in. For example, are they green, unroasted beans? Or are they roasted and in a vacuum-packed bag on the shelf at the supermarket?

Let’s dive in…

Green coffee beans

Many coffee companies will tell you green beans, stored in the right conditions, can last years. Others will tell you that green beans are only good between six and eight months of harvest, while many other companies claim that the sooner a bean is roasted, the better.

It’s a convoluted topic. But, if we consider the biology of it all, we can begin to make sense of this confusion.

When a coffee bean is in its raw state, it’s often been through a process of extraction from the cherry, as well as a washing or drying period, which helps to remove pulp and mucilage from the cherry itself.

Green coffee beans are the seeds of coffee cherries. When they’re uncooked, they differ little to other beans or seeds when in their raw state, like kidney beans, flower seeds or peas – the sort of seeds and beans you store in your pantry for a long time.

Stored in the right conditions, then, green coffee beans can last a very long time. Factors that will affect the shelf life of your green coffee beans include:

–       Sunlight

–       Humidity

–       How you store your coffee

To give your green coffee beans a long shelf life without spoiling them, it’s recommended that they’re stored in a cool, dark and dry place.

Our advice is to roast green coffee beans within their first year of life. Once a bean has been picked, processed and packed, it will begin degrading, as is the norm for any product you purchase.

Roasted coffee beans

Roasted coffee beans are a different story entirely. Much like any food you roast, its shelf life will be considerably shorter, and there are many chemical reactions that occur that both gives coffee its flavour and reduce its life.

A few notable changes include:

  • Decomposition of sucrose
  • Loss of free water
  • Decrease in total protein
  • Loss of chlorogenic acid
  • Decomposition of trigonelline
  • Formation of melanoidins

But the biggest of all (and a big contributing factor to whether or not coffee will expire) is the oxidation process.

When a green coffee bean is roasted, it begins to release carbon dioxide into the atmosphere (much like any living thing) and will react to the oxygen in the air around them. As much as oxygen is essential to life, it also works to suck the life from living things. It is why apples turn brown, why the Statue of Liberty turned green, and, without getting too deep, it’s why all humans die.

Freshly roasted coffee releases more CO2 than aged coffee, and it’s this CO2 release that reduces effects of oxidation and gives coffee it’s flavour and quality.

The best time to drink coffee, then, is as close to its roast date as possible. The longer the gap between roasting and consumption, the less flavour coffee beans have, and ultimately, the closer it is to becoming a lifeless, flavourless and ‘too far gone’ product.

High-quality specialty coffee companies will tell you that coffee is no good 14-days after its roast date. Other places will tell you coffee can be consumed up to a month of its roast date. There is no definitive expiration date, there is only personal choice.

The best coffee is the freshest coffee

When it comes to roasted coffee going bad, the important thing to remember is that the best coffee (i.e. coffee with the most flavour and that retains its quality) is fresh coffee.

Much like a recently yellowed banana, or a soft and green avocado, there is a period of time that coffee is in its prime. But, unlike these fruits, it takes a long time for coffee to reach a point of no return. Sure, it does go bad, but does that mean it’s undrinkable? That’s your call. As author Cassandra Clare once said:

‘As long as there was coffee in the world, how bad could things be?’

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