Quick answer: There are four main types of coffee roasts: light (356–401°F, bright acidity, most caffeine by weight), medium (410–428°F, balanced body and flavor), medium-dark (437–446°F, bittersweet, surface oils visible), and dark (464–482°F, smoky, lowest acidity). Each roast level changes the bean's flavor, body, and caffeine differently, not just the color.

Walk down any grocery aisle and the bag labels will drive you a little crazy. Cinnamon Roast. City. Vienna. French. Italian. Every brand uses different names, and none of them have agreed on what those names mean. One roaster's "medium" is another's "Full City," and a third just calls it "Breakfast Blend." That's not confusion — it's just how the trade evolved. Roast names were never standardized.

What is consistent, though, are the four temperature bands every roast falls into. Learn those and the labels stop mattering. Here's what each band actually does to the bean, how it changes what's in your cup, and when you'd actually want to reach for it.

Light roasts: brighter, more acidic, and more caffeinated than most people expect

Light-roasted beans top out at 356–401°F internally. The roaster pulls them shortly after first crack — that audible pop when steam pressure finally ruptures the bean's cell walls and the bean starts to expand. If you look at a light-roasted bean, the surface is completely dry, almost chalky. No oils. No sheen.

Because heat gradually breaks down caffeine and burns off acids over time, stopping early means you keep more of both. By weight, light roasts actually carry more caffeine than dark roasts — though if you're scooping by volume rather than using a scale, the gap shrinks fast, because light beans are denser and heavier per scoop. The bigger story at this roast level is flavor. A light roast is where origin character lives. A washed Ethiopian Yirgacheffe tastes nothing like a Kenyan SL28 at this temperature, and neither tastes like a Colombian Castillo. The roast hasn't flattened those differences yet. You get bright citrus, berry, sometimes a floral note that's completely gone the moment you push the beans any darker.

Here's the honest catch: light roasts are unforgiving to brew. They resist extraction. Brew them too cool or too coarse and you get something sour and watery, not bright and complex. If you've ever had a pourover at a specialty shop and thought it tasted like hot lemonade, you were probably drinking a light-roasted single-origin that someone brewed slightly wrong. Grind finer than you think you need to, and push your water temperature up to 94–96°C. Don't treat a light roast like a supermarket drip blend.

Common names: Cinnamon Roast, New England Roast, Half City, Light City.

Medium roasts: the American default, and honestly, it earned that spot

Medium roasts land between 410–428°F, settling in the window between first and second crack. The surface is still mostly dry, but the bean is noticeably deeper brown and a touch less dense than a light roast.

This is the roast that built American coffee culture, and there's a reason it stuck. Medium roasts develop more body than light roasts without pushing into the smoky, bitter territory you get further down the temperature scale. Acidity backs off but doesn't disappear entirely. You trade some of the sharp, origin-specific brightness for a rounder sweetness and a more consistent result across different brew methods — drip, French press, Aeropress, all of it works well here.

If you're buying beans to brew at home and you don't know where to start, an honest medium roast from a small roaster you trust is genuinely the lowest-risk choice. You're not fighting the extraction challenges of a light roast or the bitterness ceiling of a dark one. It's forgiving. That's not a knock on it — that's useful.

Common names: House Blend, Breakfast Roast, American Roast, City Roast, City+.

Medium-dark roasts: where the oils show up and the flavor shifts

At 437–446°F, you've crossed into medium-dark territory — right at or just past second crack. This is the first point where you'll see oils on the bean's surface, that faint glossy sheen you notice on some whole-bean bags when you pour them into a grinder.

The flavor changes meaningfully here. Medium-dark roasts start trading origin brightness for something bittersweet and heavier. A Vienna Roast or Full City+ in this range tastes less like the farm it came from and more like the roasting process itself: dark chocolate, brown sugar, a slight charred edge. That's not a flaw — it's actually what a lot of people are looking for, especially with espresso. The heavier body cuts through milk and foam in a way a lighter roast often won't.

Common names: Full City Roast, Full City+, Vienna Roast, After Dinner Roast.

Dark roasts: smoky, low-acid, and easier to over-extract than you'd think

Dark roasts push up to 464–482°F. By now the beans are deeply oily, significantly expanded, and noticeably lighter in weight than when they went in — a lot of moisture and CO2 have cooked off. Once you're in French Roast territory around 482°F, the bean's origin is essentially gone. What you're tasting is the roast's own chemistry: smoky, bittersweetly caramelized, sometimes with an ashy edge.

Dark roasts have the lowest acidity and the lowest caffeine by weight. The extended roasting time degrades more caffeine molecules, and you're also working with a lighter, more porous bean that extracts very quickly. That combination makes dark roasts surprisingly easy to over-extract. If you're pulling espresso with a dark roast and getting a sharp, charcoal-heavy finish, try dropping your brew temperature 2–3°C and shortening contact time before you touch anything else.

Italian Roast pushes even darker and is the dominant style across European espresso traditions. French Roast and Italian Roast got their names from historical preference, not from where the beans come from.

Common names: French Roast, Italian Roast, Espresso Roast, Continental Roast, Spanish Roast.

What the roasting process actually does to a green bean

A green coffee bean is just a seed — the seed inside a coffee cherry. Raw, it smells faintly grassy and earthy. Nothing about it hints at what ends up in your cup. Roasting is what creates all of that.

As the bean heats up, moisture evaporates first. Then the Maillard reaction starts: amino acids and sugars interact under heat, generating hundreds of flavor and aroma compounds and turning the bean brown. Around 401°F, internal steam pressure gets high enough to rupture the cell structure — that's first crack, that popping sound. Around 437°F a second crack follows as CO2 escapes more rapidly. At each stage, acidity drops, bitterness builds, and the oils inside the bean start migrating outward toward the surface.

One thing I think more roasters should say out loud: the roast level matters, but it doesn't save bad coffee. A poorly grown, poorly stored, or old green bean roasted light is still a bad cup. Sourcing matters just as much as the temperature chart. The roast can't fix what wasn't there to begin with.

Quick-reference comparison table

Frequently asked questions

Which roast has the most caffeine?

By weight, light roasts retain slightly more caffeine than dark roasts — the longer roasting process degrades caffeine molecules over time. If you're scooping by volume instead of weighing, the gap narrows considerably. Dark roasts are less dense, so a level scoop holds fewer grams of coffee. If the caffeine difference actually matters to you, weigh your doses rather than scooping.

Does dark roast taste stronger than light roast?

It tastes more intense and bitter, sure. But "stronger" depends entirely on what you mean by it. Light roasts have more acidity and more layered flavor — they just don't taste bold in the way most people expect. Dark roasts carry less caffeine and less origin character. If you want a genuinely stronger cup in terms of caffeine and brightness, a well-brewed light or medium roast at the right ratio will outperform a dark one.

What is first crack in coffee roasting?

First crack is the audible popping sound that happens when internal steam pressure ruptures the coffee bean's cell walls, somewhere around 356–401°F. It's the clearest signal that a light roast is close to done. Roasters use it as a timing benchmark — when to stay the course, when to pull the beans. Second crack follows around 437°F and marks the beginning of medium-dark territory.

Why do dark roast beans look oily?

Once roasting temperatures climb past about 437°F, the oils inside the bean start migrating to the surface. That slick sheen you see on a bag of dark roast is those oils. They're also a big part of the aroma you get when you open the bag. The downside: oily beans go stale faster, and over time they can gum up burr grinders. If you're running dark roasts through a burr grinder every day, plan to clean the burrs more often than you would with a light or medium roast.

What does "Full City" or "Vienna Roast" actually mean?

They're traditional roast-level names tied to specific temperature and color ranges. Full City and Full City+ sit in the medium-to-medium-dark range, roughly 428–446°F. Vienna Roast lands on the darker end of medium-dark, around 446–454°F. The names come from historical roasting traditions in those cities. They're not standardized across the industry, though — one roaster's Vienna is easily another roaster's Full City+, so always look at the bean itself if you're unsure.

Are light roasts better for espresso than dark roasts?

It depends on the style of espresso you're going for. Traditional Italian-style espresso uses medium-dark to dark roasts — the lower acidity and heavier body hold up through 9-bar extraction and pair well with milk. Third-wave specialty cafes often pull light to medium roasts for single-origin espresso, chasing a brighter, more complex shot. Light roasts for espresso need higher brew temperatures and sometimes pre-infusion to extract cleanly. They're less forgiving on home equipment, so if you're just getting started, a medium or medium-dark roast is a more stable place to learn.

How do I know what roast level is in a bag if it doesn't say?

Look at the beans. Light roasts are dry, matte, and medium-brown. Medium roasts are a deeper brown, still mostly dry to the touch. Medium-dark roasts show some surface sheen or patches of oil. Dark roasts are heavily oily and very dark brown, sometimes nearly black. If you're still not sure, smell them: light roasts carry grain and fruit notes, while dark roasts smell smoky and chocolatey before you've brewed a single cup.

Key takeaways:

• The four roast levels are light (356–401°F), medium (410–428°F), medium-dark (437–446°F), and dark (464–482°F), each with a distinct flavor profile, body, and caffeine level.
• Light roasts retain the most caffeine by weight and the most origin-specific flavor; dark roasts are lowest in both and highest in bitterness.
• Surface oils appear starting at medium-dark; a dry bean surface means you're working with a light or medium roast.
• Roast names like "French," "Vienna," and "City" are not standardized across the industry. Temperature and color are the reliable reference points.
• The quality of the green coffee matters as much as the roast level; a poorly sourced bean won't improve at any temperature.