How Does Coffee Age?

Coffee, like most foods, ages slowly but surely over time. Here's how to taste for it—and make the most of it.

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We talk a lot about freshness in coffee. By and large this is a good thing, because it’s a simple acknowledgment that coffee is an agricultural product, and that it ages over time. You probably know to grind your coffee just before you intend to brew instead of getting it pre-ground, or to look at the roast date on a bag to determine how old it is. But freshness isn’t always so linear. 

On the latest episode of the Boss Barista podcast, I chatted with Baylee Engberg, head roaster for Trailhead Coffee in Portland, Oregon. We delved deep into the topic of “past crop” coffees, or coffees that are generally over a year old and still on hand when the new year’s harvests come in. Because COVID-19 has disrupted coffee buyers’ projections, more roasters and importers than ever have past crop coffees in storage right now—and no firm plan on how to handle them. 

It’s true that coffee degrades over time. Usually coffee is at its peak between six and eight months after being harvested, and the conditions under which a coffee is picked, packaged, shipped, stored, and roasted can all affect how fresh it tastes. But the pandemic means many businesses are not moving through coffee as quickly as they used to, so as an industry, we have to contend with what to do with coffees that don’t taste quite as good as they did at their peak. 

Why does this matter? It’s an issue of sustainability: 

I think past crop is almost an eye-roll because we all assume that it’s just becoming this terrible thing in our warehouses. And it likely isn’t, but for whatever reason, I think the U.S. has this connotation with past crop where they’re like, “Oh gosh, no old coffee, never,” and I just don’t think it’s sustainable...

And as far as sustainability with coffee goes, we all, I hope, care about farmers and we all talk about caring about farmers, but frankly, if there’s coffee on the ground, why are we not buying it up before we produce more? 

I think that that’s incredibly wasteful and I’m not necessarily pitching for everybody to go buy some past crop right now, but it usually is cheaper. And why would you waste it? I’m sure there’s a menu offering where you can plug that in, whether it’s your cold brew or... 

The topic of past crop coffee is one of the most complex conversations within our industry, in part because there’s no definitive marker of a coffee’s age. You can look at a piece of fruit or a bunch of herbs and know when they’re past their prime, but there’s no visual indicator of age when it comes to coffee. Instead, you have to roast it and taste for age, which is also one of the most tricky flavor notes to identify. 

“I think it’s hard to detect. People say ‘paper’ and I think it’s expected to be this big prominent defect, but it’s really not,” says Mandy Spirito, head roaster for Little Waves Coffee in Durham, North Carolina. “It’s more of an undercurrent. I think maybe it’s difficult to identify because you have to be cupping these coffees continuously to start identifying that papery taste.” 

Mandy credits their Q grading certification—a program where you rigorously taste coffees to establish a shared lexicon and understanding of their flavors and defects—as one of the reasons they understand what age tastes like. “Everything else sticks out like a sore thumb, like quakers, phenol, mold … but age is always an issue.” they say. 

Mandy recommends two strategies when approaching older coffees: First, know which questions to ask before buying a coffee; and second, train your palate to taste for age. 

You should begin by having a clear sense of the coffee you’re purchasing. Mandy recommends establishing strong relationships with importers, having tight projection Excel sheets so you know exactly when a coffee is running out, and being direct—it can be as simple as asking an importer when a coffee was harvested, which Mandy says was a question they sometimes forgot to ask during their early days as a coffee buyer. “A good conversation to have with yourself is: ‘How do I facilitate relationships with producers/importers to be purchasing these coffees in a sustainable way?’”

Palate-training is another key. “For me, I had a lot of trouble identifying [age] from the start—I was like, what IS this nebulous age thing?—and ended up sample roasting a bunch of ancient samples we had,” Mandy says. “And it really stuck out. [It w]as like chewing paper.” 

You have to taste to really gauge how a coffee has aged, so if you can get your hands on past crop coffee, give it a spin. On the cupping table—where coffees are intentionally roasted lightly to expose their inherent flavors—that papery note might shine through more clearly. But once you taste age, what are you supposed to do with that coffee? 

Mandy agrees with Baylee: Roasters can concentrate on the sweetness that’s inherent to the coffee, and prioritize building up the Maillard reaction flavors, or the toasty browning notes, that are directly controlled by the roasting process. Past crop coffees can also find another life in a blend, or in cold brew, where acidity and flavor clarity aren’t the main goals. 

Coffee aging is a difficult topic to navigate because there are very few resources on how to buy green coffee in the first place. “Planning and projecting is HARD—I’m not here to drag people for what is ultimately a really difficult thing to do,” Mandy says. “Where’s the big info book about this? It doesn’t exist.” 

Perhaps the biggest lesson on how to deal with past crop coffee is prepare to be dexterous. Expand your palate and taste aged coffees so you know how they’ll behave, and learn to push your roasting skills when you do encounter a bag that’s potentially past its prime.

For the sake of sustainability, we can’t ignore past crop coffees just because they don’t taste pristine. Instead, find a bag of green coffee from 2018, sample roast it, give it a taste—and think about the creative options available for making the most of it.

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