DIY Roast Basics

by Whole Latte Love Updated: August 25, 2023 3 min read
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Most espresso lovers are open to experimenting with different blends, various grinds, tamp pressure and more in pursuit of the perfect beverage. But, few are actually brave enough to attempt roasting a custom coffee at home.

Unlike brewing, frothing, tamping and grinding techniques, much of the roasting process is shrouded in secrecy. As a chef may guard a prized recipe, many roasters consider their particular roasting method a trade secret. The knowledge used to transform a green bean into premium coffee is often guarded under lock and key. That's not to say you're doomed to be shut out of the roasting world. If you want to try your hand at creating a custom coffee, keep in mind that the roasting process is rooted in hard science. Understanding a few key concepts and exercising a little patience can get you well on your way to being a home roaster.

The Process

You'll need most of your five senses in order to create a successful batch of roasted coffee—hearing, sight and smell in particular. Before you begin, take a moment to make note of the color of your un-roasted beans.

It takes quite a bit of heat to transform the average green bean; we're talking 460°F -530°F. Heating virtually anything at these temperatures will generate a certain amount of smoke and odor, so it's best to roast by an open window or an otherwise well-ventilated area.

As they are introduced to heat, your beans will first turn yellow and then begin to brown. Listen carefully, a few minutes after your green beans being to roast, you'll hear a cracking sound. At this point, the natural sugars found in the beans are starting to caramelize and you have achieved a light roast. The steam being emitted will also begin take on a roasted coffee scent.

Keep roasting, if you want a medium or dark roast. If you leave the beans exposed to heat beyond a medium roast, you'll hear a second crack. At this point, you should have a very dark roast. Do not venture much beyond this point, your beans will begin to burn and the natural sugars will all be gone, leaving you with very bitter coffee.

After your beans are done roasting, they will need to be cooled before they can be stored. If you like the results, set aside some of the beans so that you will have a reference point for the next batch. Otherwise, keep experimenting!

The Equipment

I've heard of people roasting coffee in everything from a popcorn popper to a skillet and even a cookie tray in the oven. The popcorn popper seems to be the most popular improvised coffee roaster. However, it is important to keep in mind that using your popcorn popper to roast coffee will most likely void the warranty as it is certainly outside its intended use. At proper roasting temperatures, 460°F -530°F, you will be pushing the limits of the popper to the max. Don't be surprised if it burns out within a few short months.

My advice? Use the popcorn popper as it was intended; invest in a coffee roaster if you want to make coffee at home. Makeshift methods may not yield the proper results and could pose serious safety risks.

If the goal is to create a semi-professional roast, a coffee roaster is definitely the way to go. Not only are coffee roasters designed to deliver an even roast, they also offer greater heat control. The Nesco Professional Coffee Bean Roaster, available on our website, goes above and beyond; it is the only home roaster with a catalytic converter to eliminate unpleasant smoke and odor generated by the roasting process. This model also has a dedicated roasting chamber and auger to mix your beans and ensure an even roast.

Roasting is very straightforward with this Nesco model. It has a 1/3-pound capacity, which should yield enough beans for approximately 36 cups of coffee. There's a powerful heating element and two-speed fan to direct heated or cooled air through your coffee as necessary. The Nesco Professional Roaster's most convenient feature is arguably the recall option, which will let you store and recall the roasting duration. This feature makes it easy to replicate previous results.
Priced under $250, the Nesco coffee roaster is an affordable way to create fresh, custom coffee. If you're a true espresso lover, roasting your own coffee at home is an experience worth exploring.