10 Common Coffee Questions Answered: 2026 Roaster’s Guide

If you’ve ever Googled “how much caffeine is in coffee,” “is coffee bad for you,” or “why does my coffee taste bitter,” you’re in good company. These are the exact questions millions of people type into Google and AI search every single day.

At Function Coffee Co., we roast, brew, and drink coffee every single day in Northlake, Texas, so we decided to answer the top 10 most-searched coffee questions with clear, no-BS answers based on the latest science and real-world experience.

1. How much caffeine is in coffee?

A standard 8-oz cup of regular drip coffee contains 80–110 mg of caffeine.

• Single espresso shot (1 oz): 60–80 mg
• Cold brew (8 oz): 150–200 mg
• Decaf: 2–15 mg (yes, it still has some)

Pro tip: If you want consistent strength, weigh your beans and use a timer. We roast our Momentum Espresso Blend and Pioneer Medium Roast to deliver reliable, smooth caffeine without the rollercoaster.

2. Is coffee bad for you?

No—moderate coffee consumption (2–5 cups per day) is linked to better health outcomes, according to large studies from Harvard, Mayo Clinic, and the Cleveland Clinic. Benefits include lower risk of type 2 diabetes, Parkinson’s, Alzheimer’s, liver disease, certain cancers, and even depression.

The “bad for you” myth usually comes from old concerns about acidity or anxiety, but for healthy adults, the upsides far outweigh the downsides.

3. What’s the difference between light, medium, and dark roast?

• Light roast (like our Demitasse): Bright, fruity, higher acidity, with slightly more caffeine preserved.
• Medium roast (our Brainstorm & Pioneer): Balanced, caramel notes, most popular flavor profile. With Pioneer being more of a traditional taste, and Brainstorm having a touch of fig on the back.
• Dark roast (Sullivan St): Bold, smoky, lower acidity, slightly less caffeine but richer body.

Myth busted: Dark roast does not have more caffeine. Lighter roasts actually retain a little more.

4. Why does my coffee taste bitter or burnt?

Most common reasons:

• Over-extraction (too fine grind or too long brew time)
• Water that’s too hot (above 205°F)
• Old or poorly stored beans
• Cheap or stale coffee (We roast ours fresh and have the roast date on the bag, so you never have to worry)

Fix: Use fresh beans, a 1:16 coffee-to-water ratio (for drip), and water at 195–205°F. 

5. How much coffee is safe to drink per day?

Health authorities (FDA, EFSA, Mayo Clinic) agree: Up to 400 mg of caffeine per day is safe for most healthy adults—that’s about 4 cups of regular coffee. Pregnant people should stay under 200 mg.

6. Is decaf coffee really caffeine-free?

No. Decaf still contains 2–15 mg per cup. If you’re extremely sensitive, even decaf can affect sleep. 

7. What’s the best way to store coffee?

Whole beans in an airtight, opaque container away from light, heat, and moisture.

• Best: Use within a month of roast date.
• Never: Refrigerator or freezer. This is a myth for another time. It's because condensation ruins the beans.

8. Should I drink coffee on an empty stomach?

It depends on your body. Some people get acid reflux or jitters; others feel fine. If it bothers you, eat something first or switch to cold brew (naturally lower in acid). First thing I do (Tony) is drink a black cold brew every morning!

9. Espresso vs drip coffee—what’s the real difference?

• Drip: Cleaner, brighter, higher volume. More forgiving brew method.
• Espresso: Concentrated, crema, intense flavor. It's a lot easier to "mess up" the extraction if not dialed in right.

Both are “regular coffee.” While our Momentum Espresso Blend is used on our espresso bar, it was literally designed to taste amazing in both methods.

10. What’s the best coffee mug?

One that keeps your coffee hot and actually feels good in your hand. Our Signature Function Coffee Co. Mug & Saucer Set was created exactly for that reason—thick-walled ceramic, perfect weight, and branded with our running coffee cup logo so you know it’s the real thing.

The Bottom Line

Coffee is one of the most researched beverages on the planet—and the science keeps showing that your daily cup (or three) is doing more good than harm for most people.

The real secret isn’t fancy mushrooms or trendy additives. It’s fresh, well-roasted beans brewed properly and enjoyed in a mug you love.

That’s exactly what we do at Function Coffee Co.—roast small batches in Northlake, Texas, and ship fresh every week.