You probably make a decent cup of coffee at home. Maybe you even fancy yourself somewhat of an expert and think your home brew is great. But unless you’ve attended one of Crema’s coffee classes, chances are your cuppa joe isn’t quite perfect.

Tom Valentine is the education leader at the popular downtown coffee shop, and he’s armed with nearly a decade and a half of experience in the coffee and barista business. Just five minutes into his Home Brew Methods class, I was rethinking everything I ever knew about making coffee in my own kitchen.

Whether you're working with an Aeropress, Chemex, French press or even a fancy countertop espresso machine, making a good cup of coffee is “all about eliminating variables,” says Tom.

To make coffee worth the $4 or 5 price tag you’d find at one of Nashville’s high-end coffeehouses, you have to start thinking like a barista and not only fine-tune the details, but also act with consistency and precision by considering everything from the ratio of ground beans to water (Crema uses a precise 1:2.33 ratio) to other factors, including the temperature of the water and how long the roasted beans have been “degassing.” Tom says that roasted beans are better a couple days after roasting, because it allows the beans to release trapped carbon dioxide.

The coffee grinder you have at home plays an important role, too, it turns out. A couple months before taking Tom’s class, I bought a pricey bag of whole beans from one of my favorite Pacific Northwest roasters. I ground it up, threw it in my Aeropress and expected to taste the perfect cup of coffee I have come to equate with my visits to Seattle. My first sip was … not good. Bad, in fact! My mistake? Using a cheap and inconsistent coffee grinder, according to Tom.

“Think of it like gravel versus sand,” he explains. “The size of the coffee grounds determines how quickly water flows through. Sand will hold the water, while gravel won’t.”

What a waste of $15 beans. But thanks to Tom and his easy-to-follow tips, it’s a blunder I won’t dare make again.

“It’s way easier to screw up coffee than it is to do it right,” says Tom. And he’s seen it all in his day. (Another fun Tom fact: Your body can only absorb about five shots worth of espresso per hour, so ordering anything over that in an effort to wake yourself up is a waste of money). Stop screwing up your coffee. Take a few hours out of your weekend and learn how to do it right.

Coffee Classes at Crema

Includes: 30-minute to three-hour hands-on class, take-home brewing guides, with some classes including a 33 Cups of Coffee journal and take-home coffee for two

Frequency: Every Wednesday, Friday and Saturday

Cost:$15-150

Additional info: Private classes are also available

To sign up: crema-coffee.com/coffee-classes