Which Coffee Roast Has the Most Caffeine?

Light roast coffee has the most caffeine by volume, but the difference is minimal. Dark roast has less caffeine because light roasts are denser due to water loss and expansion during roasting. Caffeine levels in coffee roasts are influenced by roast temperature, duration, bean variety, and more. Light roast coffee contains roughly 95 mg of caffeine per 8 oz, while dark roasts contains 80–120 mg per 8 oz, according to the FDA.

To find roasts with the most caffeine, choose light roast beans and verify labels for caffeine content. Opt for arabica-robusta blends from specialty coffee brands for a higher caffeine dose per serving. Caffeine starts acting within 15–45 minutes and reaches its peak in about an hour, while its effects can last up to 47 hours depending on metabolism.

Which Has More Caffeine: Light or Dark Roast?

Light roast coffee contains the most caffeine per volume because lower roasting temperatures and shorter times prevent caffeine loss. Dark roasts lose caffeine due to longer exposure to heat, despite having better extraction efficiency, according to a 2025 study published in Processes by Katarzyna Rzyska-Szczupak and colleagues from Poznań University of Life Sciences. The researchers analyzed Ethiopian arabica varieties and measured caffeine in green, light, medium, and dark roasts. Light roast samples contained up to three times more caffeine than dark roast samples. Sidama light roast contained 81.47 milligrams (mg) of caffeine per 100 g, while Sidama dark roast contains only 29.07 mg per 100 g.

Light roast coffee had the highest caffeine content under identical brewing conditions in a 2024 study by Zachary R. Lindsey published in Scientific Reports. The study included 30 tests combining roast level, coffee type, and brew time. Caffeine content in light roast brewed coffee averaged about 165 mg per 8 oz (237 ml) cup, while medium roasts contain 153 mg and dark roasts 134 mg, as shown in this chart.

The amount of caffeine in light roast coffee is higher, but varies by bean and is not always statistically significant. For example, a 2011 study published in Food Chemistry by Ivana Hecimovic from the University of Zagreb analyzed the caffeine content in coffee at different roast levels. The caffeine content in roasted coffee was measured using High-Performance Liquid Chromatography (HPLC). The researchers found that caffeine levels declined as roast degree increased across most tested coffees, as shown in the following table.

Caffeine in light roast coffee remained higher in some varieties, while others showed inconsistent changes as roast levels darken. For example, light roast Cherry Robusta coffee contained 2.55% caffeine, while medium and dark roasts contained 2.52% and 2.37% respectively. For the Arabica, light roast had roughly 40% more caffeine than medium roasts and about 46% more than dark roasts.

However, the Vietnam Robusta sample had its highest caffeine content (2.47%) in the medium roast, which was significantly higher than its light roast (1.81%). This 2011 study shows that while light roasts often have more caffeine than dark or medium roasts, the specific bean type can create exceptions to the rule.

What Factors Influence Caffeine Levels in Coffee Roasts?

Caffeine levels in coffee roasts are influenced by roast temperature, roast time, bean variety, bean density, porosity, mass loss, extraction efficiency, and thermal stability. Moisture, grind size, water temperature, and storage have a smaller impact on caffeine content. The most impactful factors are listed below.

1. Roasting Temperature
2. Roasting Duration
3. Bean Species
4. Bean Porosity
5. Mass Loss

1. Roasting Temperature

Roasting temperature refers to the heat level used during coffee roasting, typically ranging from 370°F to 540°F (188°C to 282°C). Higher roast temperatures reduce bean mass and slightly decrease caffeine content. A 2021 study by Ewa Olechno published in Foods found that caffeine remains stable up to 230°C (446°F), with measurable losses above 240–260°C (464–500°F). At these higher temperatures, caffeine volatilizes slightly and bean mass decreases by 15–25% from moisture and organic compound loss.

2. Roasting Duration

Roasting duration refers to how long coffee beans are roasted. Longer roasting reduces water content and slightly affects caffeine concentration. A 2014 study by Silvia A. V. Tfouni published in the International Journal of Food Science and Technology found that increasing roast time from 7 minutes in light roast to 15 minutes in dark roast reduced caffeine by 5–10% and bean mass by 14–20%. In another study from 2020, Jesper Alstrup in Beverages found that extending development time increased caramelization and reduced bioactive compounds, including a slight decline in caffeine.

3. Bean Species

Bean species refers to the type of coffee plant, such as Arabica or Robusta. The species sets baseline caffeine content before roasting and directly affects final caffeine levels in the roast. A 2021 study published in the European Journal of Medicine and Natural Sciences titled “Determination of Caffeine Content in Arabica and Robusta Green Coffee of Indian Origin” confirmed that Robusta beans naturally contain more caffeine than Arabica beans. The study measured 182 mg of caffeine per 100 g in Robusta beans and 154 mg per 100 g in Arabica beans. No research shows that Arabica and Robusta lose caffeine at different rates during roasting.

4. Bean Porosity

Bean porosity refers to how porous the coffee bean becomes after roasting. This factor does not change caffeine content in the bean but determines how much is extracted during brewing. Higher porosity increases internal pathways and pores, letting water enter the bean easily and extract caffeine faster in darker roasts. Light roasts have lower porosity than dark roasts, which can impact caffeine content per brew depending on grind size and extraction method.

A 2024 study by Zachary R. Lindsey found that increased porosity in darker roasts led to faster caffeine extraction at equal yields, but this does not prove dark roasts contain more caffeine inherently. The study found that darker roasts extract caffeine more efficiently per unit of remaining material but yield less caffeine due to lower extraction rates and caffeine loss from sublimation during very dark roasting.

5. Mass Loss

Mass loss refers to the reduction in weight coffee beans undergo during roasting due to the evaporation of water and volatile compounds. This affects caffeine in light or dark roast because caffeine remains stable while mass decreases. A 2025 study published in the International Journal of Food Science and Technology found that coffee bean mass loss ranged from 12.57% in light roasts to 25.56% in Italian roasts, while caffeine content stayed stable across all roast levels. Darker roasts showed higher relative caffeine concentrations but lower extraction yields when mass losses exceeded about 12–14%. This means caffeine concentration per gram increases in darker roasts due to mass loss, but brewed coffee from darker roasts contains less total caffeine because reduced extraction limits yield.

How Much Caffeine is in Light Roast Coffee?

Light roast coffee contains approximately 95 mg of caffeine per 8 oz cup, or 11.8 mg of caffeine per fluid ounce, according to the U.S. Department of Agriculture. However, a number of studies showed caffeine in light roasted coffee varies slightly based on bean type, serving size, brewing method, and brand.

Light roast coffee caffeine content varies by bean type. According to the World Health Organization’s International Agency for Research on Cancer (IARC) Monograph “Coffee, Tea, Mate, Methylxanthines and Methylglyoxal,” light roast Arabica coffee beans contain 1.0% to 1.2% caffeine, while dark roast Arabica beans contain 0.9% to 1.0%. Similarly, a 2014 study by Silvia A. V. Tfouni from the University of Campinas, published in the International Journal of Food Science and Technology, found that light roast Arabica coffee contains 87.3–122.5 mg of caffeine per 100 ml, while light-roasted Robusta contains 123.3–192.0 mg per 100 ml.

The amount of caffeine in light roast espresso coffee was 7.174 g per liter, or 180 mg per 25 ml shot, according to a 2014 study by Iziar A. Ludwig at the University of Glasgow. This means light roast espresso shot contained about 212 mg of caffeine per ounce, which is roughly 17 times more than the USDA average for brewed coffee. Interestingly, a 2021 study by Shady Awwad from the Department of Pharmaceutical Chemistry and Pharmacognosy at the Applied Science Private University found that light roast had only 69.68 mg per 12 oz (355 ml) serving.

The following table compares caffeine levels in popular light roast coffee brands.

Does Light Roast Have More Caffeine?

Yes, light roast coffee has slightly more caffeine by volume than dark roast because light roast beans are denser. During roasting, beans lose water, expand, and become less dense, according to a 2012 study by Feifei Wei published in the Journal of Agricultural and Food Chemistry. When measured by scoop, light roast contains more mass and therefore more caffeine, even though caffeine loss during roasting is minimal.

How Much Caffeine is in Dark Roast Coffee?

Dark roast coffee contains about 80-120 mg of caffeine per 8-ounce serving, according to U.S. Food and Drug Administration (FDA). The International Food Information Council Foundation (IFIC) states that an 8-ounce cup of brewed dark roast coffee contains about 96 milligrams of caffeine, similar caffeine content to other roast levels. Some sources, like a 2021 study by Shady Awwad published in Molecules, report a lower range, 67.37 mg per 12 oz serving, but this is not typical for dark roast coffees.

Dark roast coffee beans contain approximately 1.08% caffeine by weight, according to the USDA. Dark roast coffee contains slightly less caffeine per volume than light or medium roasts because the longer roasting process reduces its concentration. However, the exact caffeine levels depend on bean variety, roast duration, and brewing method. For example, a 2015 study by by Rafael C. E. Dias published in Beverages found that dark roast Robusta beans contain nearly twice the caffeine of dark roast Arabica, with 2.35 g per 100 g compared to 1.35 g per 100 g.

Dark roast coffee caffeine content varies by serving size and brew method, with larger volumes containing more caffeine due to increased brewed coffee. For example, a Starbucks dark roast brewed coffee contains 195 mg of caffeine in a Tall (12 fl oz) serving, 260 mg in a Grande (16 fl oz) serving, and 340 mg in a Venti (20 fl oz) serving.

The following table lists popular dark roast coffee brands and their caffeine levels per serving.

What is the Most Caffeinated Coffee You Can Buy?

The most caffeinated coffee you can buy is Devil Mountain Coffee Black Label, containing 1,555 mg of caffeine per 12-ounce cup. This coffee holds the highest caffeine content of all commercial coffees and delivers a strong energy kick. High-caffeine coffee brands achieve high caffeine levels by blending Robusta beans, which have naturally more caffeine than Arabica beans.

Where to Buy High-Caffeine Coffee Online?

You can buy high-caffeine coffee online from Colipse at colipsecoffee.com. At Colipse Coffee, our high-caffeine blend combines Indian Robusta Cherry and Tanzanian Bourbon beans for maximum strength and flavor clarity. Colipse High Caffeine Blend has over 400 mg of caffeine per 16-ounce serving. We roast to order and ship within 3–5 days to ensure peak freshness. Our beans deliver bold chocolate and berry notes with extra caffeine for high-energy coffee drinkers. Pricing starts at $21.50 for 12 oz with free U.S. shipping and subscription discounts available.

How to Brew Coffee for Maximum Caffeine?

To make coffee with the most caffeine, follow the five steps below.

1. Use Robusta beans instead of Arabica
2. Grind beans fine to increase extraction
3. Brew with hot water between 195°F and 205°F
4. Use longer steeping times, especially in French press
5. Increase coffee-to-water ratio (e.g., 2 tablespoons per 6 oz)

How Long Does it Take Caffeine to Work?

Caffeine begins to work within 15 to 45 minutes after consumption, according to the European Food Safety Authority, the U.S. National Center for Biotechnology Information, and Frontiers in Nutrition. Caffeine is almost fully absorbed within 45 minutes, reaching peak blood levels between 30 and 60 minutes, and that its stimulatory effects can start as early as 15 minutes after ingestion and last several hours.

How Long Does it Take for Caffeine To Wear Off?

Caffeine wears off in 7.5 to 47.5 hours, depending on the individual's metabolism, according to Jericho Hallare, a general surgeon from Maywood, Illinois. This range equals four to five half-lives of caffeine in a healthy adult. Dr. Jericho Hallare explains that a caffeine is considered eliminated after 4 to 5 half-lives, when 94% to 97% of it is removed from the body and plasma concentrations fall below clinically relevant levels. Factors like age, liver function, medications, and pregnancy can extend or shorten this duration.