Understanding Sweetness in Coffee

For some people, coffee tastes like coffee. For coffee people, nuances and aromas are what make drinking coffee one of life’s greatest gifts. When we talk about the language of coffee, coffee characteristics like ‘acidity,’ ‘bitterness,’ and ‘sweetness’ come up a lot, as does the topic of naturally sweet coffee.

Understanding sweetness in coffee is a tricky subject because it’s still a bit of a mystery. But we do know a few things.

For one thing, coffee comes from a fruit tree. The coffee we know and love is the seed of a fruit called coffee cherry. When coffee cherry is picked, the fruit part is removed in processing and what’s left is the seed. Because the fruit has naturally occurring sugars, it imparts some of its sugars into the seed. The raw, green coffee seeds have a small amount of sucrose, fructose, and glucose, but once you apply high heat in the coffee roasting process, whatever residual sugars were in the raw coffee get burned off. In a cool process that science nerds call the Maillard reaction and what most of us call caramelization, when heat is applied, molecules change. And it’s this process—and the amazing flavors it draws out of roasted coffee beans—that make us think of sweet things, like dark chocolate. And our minds remember having eaten dark chocolate and think “sweet!” More science talk: this is called cross-modal perception, and for you and me, what that means is memory.

The aroma you enjoy from a cup of coffee reminds you of something sweet you’ve had before; alfajores cookie, a handful of fresh blueberries, an oozing chocolate bar, or a bouquet of flowers. And this perception is then translated into what you’re tasting.

Since your sense of smell has the strongest link to emotion and memory of all your senses, if we put that in the context of flavor and sweetness, that perception makes you think you’re tasting something sugary sweet in your cup of coffee, even though you’re not.  And since sweet smelling things conjure positive feelings—and we’re talking about coffee, after all—that’s probably why the first whiff of our morning brew fills us with such joy. So, first things first when it comes to enjoying a naturally sweet cup of coffee: take a moment to enjoy the complex aromas of your coffee as you brew.

Now for more fun: do a little research to see which coffees taste the sweetest to you. This shouldn’t be hard, as it means doing homework that consists of drinking coffee. (Easy A+) Most of your sense of taste is based on your own biology and is subjective to what you like or don’t like. Challenge yourself to try a wide array of blends, roast levels, different origins. For example, naturally processed coffees are typically much more fruit forward than fully washed coffees. Do natural process coffees taste too sweet? Try a washed Guatemalan or a Central American blend. Want to shoot straight down the middle? Try a medium to dark roast single origin Colombia. 

Go even deeper and explore the vast world of brewing. Different brewing methods, total brew time, your ratio of water to coffee, all affect the flavor profile. Coffee tasting too bitter? You might be experiencing too long of an extraction. Coarsen up your grind setting just a bit, reduce your brew time, and try again. When you play around with your brewing technique, you get the opportunity to really control your variables AND enjoy that sweet, sweet aroma up close and personal. 

- Jamie Smith: Coffee Expert, Peet's Research and Development