The roasting process brings out the flavor locked inside freshly picked (green) coffee beans, causing chemical changes in the beans (which also changes their color from green to brown/black). Newly picked beans are stored green sothat they won’t loose their taste or quality. Pick up a non-roasted bean and you’ll see that it’s soft and smells something like grass; it’s not until a bean is roasted that it will exude that well-known “coffee smell” we all love.
Roasting the beans yourself isn’t as hard as you might think, although it definitely is a process and one that needs to be monitored carefully.
Take a look below for instructions on how to roast coffee beans using a popcorn popper and a gas grill (you could roast your beans on your kitchen stove, but the smell is powerful and can last for a longish while, stinking up your home’s interior).
Your tools are minimal:
- a gas grill, but it needs to have a side burner. You can use a camping stove (make sure it’s power comes from propane) or even a full-size grill.
- A stainless steel popcorn popper. Steer clear of plastic lids as they could melt and opt for a popper with a stainless steel lid.
- An old baking sheet (you’ll cool the beans on it). It should be an old one because the smell of roasting beans will permeate from now on. (Note: roasting coffee beans smell nothing like “coffee.” The smell is strong and many people describe it as – we’re not kidding – “yucky.”
- Green coffee beans. You can buy in bulk because they can last for years so long as you store them in a cool, dry place.
- Preheat your grill’s side burner for about 10 minutes. You want to make sure the grill is HOT before roasting the beans.
- Once your burner is pre-heated, place the beans in your popper on the grill and start stirring them with the popper’s hand crank. You’ll be cranking for 10-15 minutes, so pace yourself. It’s a good idea to leave the lid open so you can watch the beans turn color.
- The beans will start to turn yellow in a few minutes. You’ll also notice steam or “smoke” coming from them – the beans are releasing water – and they will start to smell (a pungent, earthy aroma).
- Pay close attention at this point: when the beans start to turn from yellow-ish to brown, you should start hearing them crack and pop. There will be two times the beans do this (crack); this first time the sound may be very similar to corn kernels popping.
- Depending on if you want a light or dark roast – or something in between – you’ll need to soon remove the beans from the heat. If you want a light roast, remove them at the first set of cracks/popping. This light roast should be very smooth, but it may not taste like coffee as you know it.
- If you continue roasting, you’ll hear a second set of cracking. This one is much less noisy than the first set – some people describe it as popping bubbles – so listen carefully. The beans’ color also should become more evenly brown.
- Remove the beans after this second cracking should give you a normal roast. You won’t want to go much beyond two minutes from this point onward, as you could burn the beans. If you smell burning and/or if the beans start to smoke, you’ve gone too far.
- Once you take the popper off the grill, place the beans on the cookie sheet to cool. You’ll see that they are bigger and it may look as if you have a lot more beans.
- Spread them in an even layer and allow to cool for at least 30 minutes to several hours – your choice. Once cooled, blow on the beans to get rid of the remaining flakes left over from the outer bean.
- Store your beans in an air-tight container and wait about three days before grinding these beans and then brewing for coffee. It’s best to consume them within 14-21 days.