While you can use any type of toast for your espresso machine, you'll get the best results with dark roast, espresso, or French. These roasts will give you the flavor and consistency you expect from an espresso. If you prefer a lighter roast, opt for a medium roast. You can use regular coffee in an espresso machine, but the result will not be satisfactory at all.
If you put the wrong type of grind in the machine, don't expect the coffee to taste like a shot of high-pressure espresso. Ground coffee used in a drip coffee maker or French press is too thick to work properly with an espresso machine. Espresso machines use hot, pressurized water in finely ground coffee beans to create the best shot of espresso. In short, the main differences between espresso and filter coffee are their preparation times and how fine the ground coffee should be.
Now you know why it's better to use espresso beans for your espresso machine instead of using the regular, pre-ground coffee (or even the regular coffee beans) you have in your kitchen cupboard. The world of coffee can be complicated, and the jargon is sometimes difficult to understand, even for experienced coffee drinkers. Likewise, using ground espresso in a conventional drip maker may save you time, but it won't taste anything like a real cup of espresso. Regular coffee is best prepared with a medium grind, so you can never get the most out of its use with an espresso, which produces the best infusion with small grinds.
Using coffee beans is a better alternative, but if you want to enjoy the full experience and a shot of great-tasting espresso, espresso beans are your best option. If you don't have an espresso machine, it's possible to get a similar flavor with dark roasted espresso in a coffee maker. Conversely, if you use fine-ground, powdered espresso in your traditional drip coffee machine, you'll end up with a cup of bitter, burnt flavored coffee. Using regular coffee beans in an espresso machine could be your attempt to find the best-tasting coffee for you.
The answer to “Can regular ground coffee be used for espresso?” Yes, but it's not the best idea. While you can technically mash coffee beans with a mortar, the coffee beans will lack consistency and result in a mediocre shot of espresso. When it comes to espresso, it's less about a specific ground or type of coffee bean, and more about how the coffee is made. Your machine is designed to work with the precise grinding of espresso to give your coffee the best possible flavor.