When we’re crazy about coffee we often go to great lengths to secure the best beans from great farms and roasted by roasters we love, but we’re often less careful about making sure these coffees are consumed when they are at their very best. Fresh is good, but it isn’t a case of the fresher the better.
Coffees have a flavor peak at some point after roasting when they taste their best. The right amount of rest varies based on a number of factors, including roast level, variety and origin, intended brewing method, the type of roaster they were roasted on, how you store the coffee, and more! In this post, we’ll dive into why resting is so important, how it works, and I'll share some guidelines to help you get the best out of your beans.
I learnt a lot about resting coffee and how much difference it can make when I started roasting myself. It can still astound and sometimes unsettle me! I roasted a wonderful Colombian geisha not so long ago and shared a good number of samples of it with people in the local coffee community. It was a coffee I knew well and I’d roasted it using a roast profile that had given me great results in the past. At a coffee event some friends invited me to brew my coffee at their booth. It tasted ok. But not in any way what I was expecting. When I got home, I immediately brewed the coffee again and while it tasted a little better with my water, it was still not up to what I'd expected. I posted a quick story on my insta account encouraging people to wait a few days before brewing. When I brewed the coffee again myself 4 days later the flavour was so much more intense and just as I remembered previous roasts of this coffee! (It turns out that this coffee peaks at around 2-3 weeks and stays there -- albeit still evolving -- until about 5 or 6 weeks off roast.) Let's break it down step-by-step.
What Does "Resting" Coffee Mean?
Resting coffee refers to the process of allowing freshly roasted beans to sit for a period of time before brewing. Right after roasting, the beans are packed with carbon dioxide (CO2), which is released during the roasting process. Brewing filter coffee too soon after roasting can lead to uneven extraction, sour or bitter flavors, and most often just subdued and "distant" flavours. Overly fresh espresso can have a real biting edge to it.
How Long Should You Rest Coffee?
The optimal resting time can vary depending on the roast level, the type of roaster used (drum of fluid bed, for example), storage conditions, temperature and the variety/origin of the bean. This might sound like a lot but don’t panic – there are some general rules of thumb which can help us get in the right ballpark.
Light Roasts: Light roasted beans typically need a good 7–14 days of rest to allow the CO2 to dissipate and the flavors to stabilize. Light roasts tend to have more volatile compounds that need time to settle. They may well even need longer than this and if they taste flat when you try them, then put them away for a few more days and see what they are like after a bit more rest.
Medium Roasts: Medium roasts (such as Full City) benefit from 7–10 days of rest. This period allows the beans to reach their ideal flavor profile, balancing sweetness and acidity with a smooth body.
Dark Roasts: Dark roasts generally require a shorter resting period, usually 3–7 days. Since dark roasts have less CO2 trapped inside, they settle faster and are ready for brewing sooner.
The Effect of Temperature and Bag Handling on Coffee Resting
While resting is essential, how you store your coffee during this period also plays a significant role in its freshness and flavor development. Warm room temperatures and frequent bag opening can accelerate the aging process and negatively affect your coffee’s flavor. If you know the roast level and brewing method then it’s probably best to just wait until you think you are in or near that peak taste window before opening.
Warm Room Temperatures: A Quick Way to Accelerate Aging
Coffee is sensitive to temperature, and high room temperatures can cause beans to age more quickly. Storing your coffee in a warm environment can lead to oxidation, where the flavor compounds break down faster. This can result in stale, flat-tasting coffee that loses its complexity. Ideally, store your beans in a cool, dark place (around 60-70°F or 15-21°C) to maintain freshness and slow down the aging process. Don't store them in the fridge though.
Opening and Closing the Bag: Letting Oxygen In
Every time you open a coffee bag, you expose the beans to oxygen, which accelerates the oxidation process. Oxygen can cause degradation of aroma compounds, leading to staleness. Most specialty coffee bags come with a one-way valve to allow CO2 to escape without letting air in. However, if you frequently open the bag to sniff the coffee or check the contents, or even just every time you make a coffee, you're introducing oxygen and speeding up the degradation process.
Incidentally, this was a big factor behind my choosing to sell retail bags of coffee in small sizese: 6oz/170g for coffees that are very high-scoring which age less well and tend to be drunk less often compared to daily drivers which you might drink every morning to start your day. These coffees are sold in 10oz/285g bags. If you buy coffee in larger amounts, then I would highly recommend dividing into smaller amounts and then freezing them. See my blog entry on freezing coffee for more on this topic.
Recommendations from Coffee Roasters: Wide ranging recommendations.
Different coffee roasters have varying recommendations based on their roasting profiles and experience with their coffees, Curious Coffee roasts are generally best when they’ve rested for two weeks. More specific recommendations for different coffees where this deviates from this, can be found on the website shop entry for the coffee in question.
In Summary: Resting Is an important part of the equation but don't get too hung up on it
While freshness is important, resting your specialty coffee is a vital step in getting the best flavor. Depending on the roast level and rother factors outlined above, coffee can benefit from different resting times. Lighter roasts typically need more rest than darker roasts. If you’re not sure, then check with your roaster and they will likely be able to help with some guidelines for their coffees. Finally, proper storage is key. Avoid storing your coffee in warm places and don't let all your freinds open your bag to get a sniff of your new beans! If you follow these simple guidelines, you’ll get the most out of your coffee.
So next time you get a fresh batch of specialty coffee, don’t rush to brew it. After all, coffee is a craft—and sometimes, the best things really do come to those who wait.
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