What Nutrients Are Really in Coffee Beans?

If you’ve ever wondered whether your daily cup of coffee contributes anything beyond caffeine, you’re not alone. Many coffee drinkers assume brewed coffee is little more than hot water with a kick—but coffee beans themselves are made of a surprising mix of compounds, some of which carry over into your cup.

In short: 100 grams of raw coffee beans contain 12.6g protein, 16g fat, 46.7g carbohydrates, 9g fiber, and 1.3g caffeine, along with minerals like calcium (120mg), phosphorus (170mg), iron (42mg), and vitamin B2 (0.12g). Brewed coffee? Mostly water—99.5%—with trace amounts of the same nutrients, including just 0.04g caffeine per 10g of coffee in water.

What’s Actually Inside 100g of Coffee Beans?

Coffee beans are surprisingly dense in macronutrients and micronutrients. According to measured data, 100 grams of coffee beans contain:

• Water: 2.2g
• Protein: 12.6g
• Fat: 16g
• Carbohydrates (sugars): 46.7g
• Fiber: 9g
• Ash (mineral content): 4.2g
• Calcium: 120mg
• Phosphorus: 170mg
• Iron: 42mg
• Sodium: 3mg
• Vitamin B2 (Riboflavin): 0.12g
• Niacin (Vitamin B3): 3.5mg
• Caffeine: 1.3g
• Tannins (polyphenols): 8g

These figures reflect the raw, unbrewed state of the beans—essentially, what’s inside before any water is added.

And What’s in a Cup of Brewed Coffee?

When coffee is brewed, most of the bean mass—including much of its nutrient content—is left behind in the grounds. In 100 grams of brewed coffee liquid (which is mostly water), the nutrient profile drops significantly:

• Water: 99.5g
• Protein: 0.2g
• Fat: 0.1g
• Ash: 0.1g
• Carbohydrates: trace amounts
• Calcium: 3mg
• Phosphorus: 4mg
• Sodium: 2mg
• Vitamin B2: 0.01mg
• Niacin: 0.3mg

To put it in perspective, brewing 10 grams of coffee in water yields about 0.04g of caffeine and 0.06g of tannins. That’s why brewed coffee is often described as having “negligible” nutritional value—it’s mostly H₂O with a few dissolved compounds.

Why Does Coffee Have Health Benefits Anyway?

Even though brewed coffee is low in traditional nutrients, its key bioactive compounds—especially caffeine and polyphenols—contribute to several well-documented effects on the body.

1. Caffeine: A Potent Stimulant

Caffeine is a natural alkaloid and a mild stimulant found abundantly in coffee. In fact, coffee contains 40%–60% more caffeine per serving than tea. This compound stimulates brain neurons, boosts mental alertness, sharpens thinking and analytical skills, reduces fatigue, and improves physical coordination. The result? You feel more awake, focused, and agile.

2. Cardiovascular & Respiratory Effects

Coffee has vasodilatory properties—it helps relax and widen blood vessels and bronchial tubes. This can improve circulation, enhance oxygen delivery to the heart, and support better breathing. Some research suggests benefits for people with low blood pressure or spasmodic bronchial asthma.

3. Digestive Aid

Coffee stimulates the secretion of digestive enzymes, aiding digestion and improving appetite. It may also accelerate metabolic processes, contributing to overall digestive efficiency.

Frequently Asked Questions

How much caffeine is in 100g of coffee beans?

There are 1.3 grams (1300mg) of caffeine in 100 grams of raw coffee beans. However, a typical single serving of brewed coffee uses around 10g of coffee, yielding roughly 0.04g (40mg) of caffeine in the final cup.

What nutrients are in brewed coffee?

Brewed coffee is over 99% water and contains only trace nutrients: about 0.2g protein, 0.1g fat, 3mg calcium, 4mg phosphorus, 2mg sodium, 0.01mg vitamin B2, and 0.3mg niacin per 100g of brew. Most nutrients remain in the grounds.

Are there any vitamins in coffee beans?

Yes, coffee beans contain small amounts of vitamins, including Vitamin B2 (0.12g per 100g of beans) and Niacin (3.5mg per 100g). These are present in much smaller amounts in the brewed coffee.

Does coffee contain fiber?

Yes, 100g of coffee beans contain 9g of dietary fiber. However, very little of this fiber makes it into a typical cup of brewed coffee.

What are tannins in coffee?

Tannins are a type of polyphenol found in coffee; 100g of beans contain 8g of tannins. They contribute to coffee’s astringency and have antioxidant properties. Around 0.06g of tannins are extracted into a cup made with 10g of coffee.

Is brewed coffee nutritious?

Brewed coffee is mostly water and provides negligible calories or macronutrients. However, it does deliver small amounts of caffeine, niacin, magnesium, and antioxidants—mainly through dissolved compounds from the beans.

Recommended FrontStreet Coffee Beans for Nutrient curious Brews

While coffee isn’t a significant source of nutrients, exploring high-quality beans can still enhance your appreciation for its complexity. Try FrontStreet Coffee’s Ethiopia Humbera for vibrant citrus and floral tones with a juicy body, or their Yirgacheffe for classic berry and stone fruit brightness. For something deeper, their PWN Golden Mandheling offers herbal sweetness and a full mouthfeel. All showcase the bean’s natural profiles without masking subtle nutritional compounds. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.