There are a lot of things to consider when choosing a coffee roast profile. Are you aiming for a light, medium, or dark roast? How was the coffee processed, and what does that mean for your roast curve?
Brewing method also has a role. You’ll likely make different roasting choices dependent on whether the coffee will be used to make an espresso or a pour over. But why and how do we roast differently for filter coffee and espresso? Read on to find out.
Lee este artículo en español La Diferencia Entre Tostar Para Café Filtrado y Para Espresso
Inside a coffee roasters. Credit: Neil Soque
Why Have Separate Filter & Espresso Roasts?
Espresso and filter coffee are fundamentally different brewing methods. When preparing an espresso, we force hot, pressurised water through a compact puck of coffee. There is an extremely short opportunity for extraction, so we use finely ground coffee and very hot water to allow the compounds in the coffee to extract quickly.
With filter coffee, there is longer opportunity for extraction so we tend to use a coarser grind than in espresso and water that is lower in temperature. In a pour over, a larger volume of water is allowed to absorb the compounds at its own consistent time and pressure, instead of by force. The result is coffee with lower acidity and less body than an espresso made with the same beans.
Learn more in Espresso vs Filter: What’s The Difference?
Bags of green coffee ready to be roasted. Credit: Ana Valencia
Coffee that is roasted dark is more porous than light roasts. This means that medium and dark roasts are more soluble, extract more quickly, and may be better suited to different brewing methods than light roast.
Of course, we can adjust variables such as grind size to compensate, but the general rule is that a light roast works best with a slower extraction method, such as a filter coffee, and a darker roast with a quick method such as espresso. This is because of the differences in solubility. But it’s not always that straightforward.
“You can have filter coffee that’s dark, espresso that’s light, and vice versa,” says Trey Cobb, Co-Founder of Greater Goods Coffee Roasters in Austin, Texas. “In some cases we’ll roast the same coffee that may perform best for filter or espresso with the same end temperature but the roast profile is drastically different. It’s down to what you want to convey in the coffee, knowing how it’ll be brewed.”
Brian Webb is a roaster and SCA Trainer at Pacific Coffee Research in Kona, Hawaii. He says, “I generally approach roasts for filter brewing and espresso in very different ways. A fast, light profile that presents floral notes and sparkling acidity in a filter brew might be unpleasantly tart and funky in the espresso machine”.
This difference would be caused by different rates of extraction. Fruity and acidic notes are extracted first, followed by sweetness, and then bitterness. So if a coffee doesn’t have enough opportunity for the sweet compounds to be extracted, it will taste tart.
Learn more in Understanding Coffee Extraction For Your Perfect Cup
A bag of roasted coffee beans. Credit: Nadia Valko
How to Roast For Different Brewing Methods
With espresso, light roasts are at risk of being under-extracted and tasting sour. So many people roast darker for espresso, to ensure the beans are very soluble. But there are roasting techniques that allow the beans to become more soluble without being dark roasted.
“The most common misconception I encounter among novice roasters is that well balanced espresso requires a darker roast,” says Brian. “This is not always true. I almost always roast slower for espresso compared to filter, but almost never go darker.”
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A carafe of freshly brewed filter coffee. Credit: Neil Soque
Lukasz Jura is the owner of Coffee Proficiency, a green and roasted bean supplier in Krakow, Poland. He says, “Filter roasts are usually more dynamic and shorter. That helps us to preserve origin flavours in our final products. Espresso is a bit different, because we need coffee to be a little more brittle, easier to extract and control. That’s why we roast [these coffees] with longer development time.”
Brian says, “Don’t rely entirely on cupping when developing espresso profiles. Things change dramatically when you put your coffee under nine atmospheres of pressure, so make sure you taste your espresso as espresso.”
Freshly roasted coffee spills out of the roaster. Credit: Battlecreek Coffee Roasters
- Roasting for Filter
Filter coffee highlights a coffee’s individual flavour notes, so roasting for filter should focus on preserving the specific characteristics of that coffee. Generally speaking, the longer beans spend in roast development, the more body the coffee will have, but the more acidity and fruitiness will be sacrificed.
In general, coffee that endures a longer development stage will have more caramelisation and sweetness. If you want to highlight fruit flavours, roast with a shorter development stage. For a more chocolatey flavour, try keeping it here a little longer.
Roasted coffee beans. Coffee and I
Trey says, “We have a lot of customers who judge our coffee based on a pour over or batch brew,” he says. “The goal is a profile that balances acidity with sweetness and builds ample body. We like a layered flavour profile and a distinct start, middle, and finish.”
He tells me that there is no one roasting profile that creates an ideal filter roast. “We want the coffee to take the drinker on a journey as it cools, not one that screams one primary note and then falls apart. How we get there differs with each coffee but we can usually land on a profile that achieves this goal.”
Freshly roasted coffee in cooling tray. Credit: Devon Barker
- Roasting for Espresso
Espresso roast needs to be more soluble than filter roast, but how do you achieve this? Several roasters told me that they use a longer roast than with filter coffee, but don’t necessarily increase the temperature or create a dark profile.
“When roasting for espresso, we think about opening the window of ideal extraction [through solubility] and how the acidity will be amplified,” Trey says. “Often that requires a longer roast to further break down the bean and its chemical compounds. Maybe that’s post crack development, maybe before first crack, or a combination of both. We typically find the latter is the case.”
“On the cupping table, it may not be as balanced or dynamic but so long as the sweetness is dominant, we find it works well when brewed as an espresso, which highlights the acidity to finish out the end result.”
Shots of espresso. Credit: Neil Soque
Lukask says that extended development time makes coffee “more delicate” but easier to extract in a shorter brewing time. “It changes coffee a bit so it’s easy to recognise the roast characteristics on a cupping table, but when you brew it properly, you can enjoy well-developed and extracted coffees,” he says.
Brian tells me, “I’ll typically roast to the same time and temperature post-first-crack, but I’ll extend the Maillard phase for espresso in order to develop more pleasant bitterness and base-notes which help to maintain balance under pressure.”
Coffee beans and ground coffee in portafilters. Credit: Zarak Khan
What About Omni Roasting?
Omni roasting is when you roast beans to be brewed in any method. This doesn’t mean that the coffee will always taste the same – brewing method will still impact flavour and body. But in theory, omni roasted coffee will taste good prepared as both filter and espresso.
Brian says, “From a business standpoint, I like it a lot. It saves on labour, packaging costs, and eliminates a lot of logistical burden in the roastery. I don’t think it’s always going to lead to the best presentation of a coffee though”.
In omni roasting, you’re likely to want a middle-ground amount of time in development. This will allow the beans to become soluble enough to work in an espresso but preserve a range of flavour compounds to allow the coffee to taste balanced with any brewing method.
As with all roasting, each coffee will have different characteristics and you should sample a variety of profiles in test roasting. With omni roasting, try each profile with several different brewing methods.
Roasted coffee drops into the cooling tray. Credit: Neil Soque
Trey tells me that omni roasting “appeals to home consumers who may or may not have an espresso machine at home”.
“When we’re selling online or through our cafés, we don’t know how they’re going to brew it,” he says. “Omni roasting gives us a firm middle ground to hopefully appeal to a larger portion of the market. It also helps with our wholesale customers, one of whom may choose to batch brew a coffee while another runs it as their featured espresso.”
But he acknowledges that omni brewing may not allow the best qualities of a coffee to shine. “Omni roasting can lead to the coffee underperforming for some customers and baristas, who are judging us as a roaster based purely on their preferred brewing method. It’s tricky when trying to impress a new potential account.”
Lukasz tells me, “I’ve never done an omni roast that I was happy with both as filter and espresso. I’m not saying it’s impossible to achieve, but so far for us it’s always been best to roast separately for filter and espresso.”
Find out more in Omni Roast: Is There One Roast to Rule Them All?
A roaster checks the beans. Credit: Battlecreek Coffee Roasters
There’s no one roast profile for espresso or filter and each batch of green coffee beans will have its own qualities. But by understanding extraction and roast development, you can make a more informed choice of whether to roast differently for espresso and filter.
Regardless of whether you choose different roast profiles or to go with omni roasting, it’s important to cup regularly. You should also sample brew the coffee with the method it’s intended for. By paying close attention, you’ll be able to roast delicious coffee for any brewing method.
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