Light and Dark Roast Coffees: What are the Differences?

Why do different coffees have such different tastes? After all, they’re coming from a similar bean, right? Could it be climate? Bean origin? Roast time?

It may surprise you to know that flavor profiles have little to do with the beans’ origin and primarily derives from the roast process: temperature, time, and even the capacity of the roaster. Roasting coffee beans for delicious light and dark roast coffees with dependable flavor profiles is a science.

Light Roast and Dark Roast: First, let’s talk flavor.

Coffee beans are coffee beans. There is not something called a light coffee bean and dark coffee bean when they are harvested. What makes the beans light, medium, or dark is the roasting process.

Light roast coffee tends to have fruitier and brighter taste notes. That’s because the coffee bean is not roasted at a very high temperature, which allows these notes to stay intact.

Darker roast coffee beans are darker brown and oils are released onto the bean in the roasting process, which adds to the flavor. Generally, you get a smokier flavor (due to the high temperature).

Which roasts have more caffeine?

There has been ado about how dark roast coffee actually have less caffeine content than light roasts. The thought process is that caffeine begins to burn off during the roasting process, but caffeine burns off at a high temperature than most roasters roast their beans in the first place. Cambio’s dark roast K-Cups® have a higher number of grams, which means the caffeine profiles of our roasts are fairly similar.

That’s because the beans themselves have no difference in caffeine content themselves. Dark roast beans expand a bit with the roasting process, so if you’re measuring in volume, you may get fewer beans per scoop, which can mean that, with lighter roasts, you have slightly more density of beans and caffeine.

The difference in light and dark roast coffees as it pertains to caffeine, in other words, is small.

What does the roasting process look like?

Firstly, you have to ensure that the coffee beans stay in constant motion. This ensures that none of them will become scorched. Secondly, the heat has to be just right. Roasters usually heat to temperatures between 370-540 degrees Fahrenheit, but it’s not just about that.

The slightest fluctuations throughout the process can change the flavor notes pretty drastically. The longer you roast, the darker the bean gets. If you aim for a full body and chocolate notes, this is your go-to move. However, you will lose that fruitiness that lighter roast coffees boast.

So how do we ensure that every batch of Cambio coffee tastes the same as before? It’s a lot of chemistry (and maybe a bit of magic). First, the temperature has to increase at the same rate over the same amount of time for each batch, and air flow has to be adjusted accordingly. Second, it has to roast for the same amount of time according to the roast notes. Since Cambio has eight coffee blends, you can imagine that this takes perfection--something we are whole-heartedly committed to.

When your roasting is underway, you’ll start to hear crackling sounds. That sound is the beans expanding leads to the “first crack.” The difference in light and dark roast coffees is that darker roasts also have a “second crack,” which announce that it’s time to go into the cooling tray. The second crack means that oils will appear on the outside of the bean, which leads to the richer, bolder, smokier flavors. These different roast times give light and dark roast coffees their dominant flavors that drinkers have come to anticipate when purchasing their preferred blends.

What does “small batch” roasting mean?

At Cambio, we roast small-batch coffees from a roastmaster in California. But what does “small batch” mean, exactly? Well, this refers to the size of the roasting equipment itself and the capacity of how many beans are inside the roaster (most manufacturers recommend using only 75% of the drum). Small batch roasters allow you to be strategic and steadily make fresh coffee without too-hefty a demand. In other words, you can sell what you create and not a have lot left over going stale. Bagged coffee is best tasting when it’s consumed within two weeks of its roast date. K-Cups® are packed with extremely low levels of oxygen, which allows the K-Cups® to have a much longer shelf life.

How does a roastmaster know when roasting is complete?

Besides the “recipe” of sorts, roastmasters rely on their senses to determine if the coffee beans are properly roasted--namely sight and smell. The colors are easily determinable, but the smell is honed to keenly sense slight variations. This skill cannot be underestimated and it’s why choosing an experienced roastmaster drives every step of the process from bean to cup. Once the beans are cooled, it’s very obvious to an experienced roastmaster which are light, medium, and dark.

Why do some roasts taste bitter?

If you think some coffees have more bitterness to them, you’re not alone. And the answer to why is organic acids. These acids, like trigonelline, increase as beans heat up and increase the bitterness in lighter roasts. However, chlorogenic acids also break apart as the beans continue to roast and cause a bitter by-product noted in dark roasts (Cook’s, 2016). Therefore, there can be bitterness in both light and dark roasts, but for different reasons.

Why do some roasts taste sweet?

Everyone loves a little sweetness to their brews, right? Roasting actually burns off the sugars that are naturally in the beans, but the process can create other sugars as well. Therefore, the rate at which the beans cool off can influence their natural sweetness. The faster, the sweeter.

How can I choose a low-acidity coffee?

There are nine different kinds of acids in coffee:

chlorogenic
quinic,
citric,
acetic
lactic
malic
phosphoric
linoleic
palmitic (Healthline).

Acids are released from the beans during the roasting process, which might make you think that the less time a bean is roasted, the less acidity it will have. But this isn’t the case! Dark roasts, as well as Arabica beans, generally have a lower acidity level than their light or medium counterparts. So if you’re trying to watch your acid intake, go dark!

Can I predict how a roast will taste?

After reviewing that coffee can have 1,000 tasting notes, you may begin to wonder how you’ll be able to properly predict how your brew will taste from product pages alone. Here are some easy ways to ensure you’re buying the right roast for your preferred taste.

Given that caffeine content is barely different, we can count that out as a primary deciding factor. Instead, you should focus on tasting notes.

Light roast coffees are going to be lighter in color and slightly smaller than their darker roast counterparts. Because of their curtailed roasting time, they will have a fruitier palette; think: apple, peach, citrus, or berry. You will also get some mild acidity, as light roast coffees have more acids than darker.

If this sounds like heaven to you, we recommend Cambio’s Donut Blend K-Cup, which has citrus notes, or Cambio’s Hazelnut Blend K-Cup, which has a rich, nutty flavor. Both

Dark roast coffees are going to be darker brown in color and slightly larger, due to expansion. Because of their lengthened roasting time, they will have a smokier palette; think: chocolate, toasted nuts and cedar.

If this is what you want every morning, then Cambio’s Special Dark is for you. With diminished acidity, you have the bold flavor that persists even after adding cream. This blend has a thick body and earthy aroma.

Can’t decide what to go with because it all sounds delicious? Then medium blends might be the right idea for you!

What about medium roasts?

As you may suspect, medium roast coffees have the best of both worlds and present a happy medium between light and dark roasts. Firstly, their color is brown but not dark brown. Secondly, they lose the heavier floral and citrus notes that are common in light roasts. However, they are known for a little thicker body and slightly bolder taste than light roasts. Therefore, if you can’t really decide between light and dark roast coffees, medium roast could be for you. At Cambio, we have three medium roasts, including one of our best-sellers: Cambio’s Medium-Dark Sumatran Blend.

What’s a house blend?

Most roasters have a house blend, which essentially means that it’s a blend you can rely on to be in stock and putting the roaster’s best foot forward. It’s usually a medium blend to please every kind of coffee drinker. When in doubt, try a house blend. It’s unique blend of flavors will generally tell you everything you need to know about that roaster, including allowing you to predict the differences between their light and dark coffees.

Got more questions about Cambio coffee blends, our recyclable K-Cups, or Cambio’s profit-share model? We’d love to hear from you! Shoot us an email and we’d be happy to answer any questions you have.