Is it true that espresso does not have as much caffeine as regular coffee?

I've heard that myth as well, and as near as I can figure it comes from the notion that espresso usually comes in tiny little cups, while regular coffee comes in huge tanker trucks with handles attached. Espresso is brewed by forcing steam through the beans, which gets out basically every last iota of coffee goo from the beans. If you had equal volumes of steam-brewed espresso and drip-brewed coffee, the espresso would have a lot more caffeine.

Yes and no. By standard serving size, espresso has less caffeine than regular coffee. However, espresso is served in a smaller amount than regular coffee. If you consider equivalent amounts of each, then espresso would have more caffeine.

Amount for amount, the espresso roast is the darkest, and therefore the beans have less caffeine than regular roasted beans of coffee.

However, espresso is made by forcing a tiny bit of water through a LOT of delicious grounds.

So, actually, a shot of espresso is about equal to a standard cup of coffee as far as caffeine goes.

Here's the thing with coffee, the lighter the roast the more caffeine, but yes espresso does have more caffeine because it's concentrated into a shot. So with this in mind if you use light roast coffee for espresso it's even more caffeine.

Espresso has 35mg of caffeine for approximately 1 oz. or 70mg in a 'double shot'. Coffee has anywhere from 80-250mg in an 8 oz cup.

Essentially, this means that per ounce, espresso has more caffeine, but you would never drink 8 ounces of espresso. If you take a latte or cappuccino made with a double shot, it's less than the average cup of coffee.

Starbucks, however, has a lot of caffeine. Their "grande" has anywhere from 370mg to 500mg (differing reports). Take a look at the database for more info:

http://www.energyfiend.com/the-caffeine-database/

Don't confuse flavor with caffeine. Espresso has more flavor than regular coffee. It also has less acid than regular coffee.

Espresso has more caffeine, that's why they only put a shot or two in your drink and it gives you a crazy buzz!

If by regular coffee you mean instant coffee, than yes. This is because espresso coffee is made from arabica coffee beans, whereas instant coffee is (generally) made from robusta coffee beans. Arabica beans are of a higher quality and contain less caffeine than robusta beans.

Espresso is more highly concentrated in caffeine.

115 for regular coffee

80 for espresso if brewed properly.