I had the privilege to own and operate one of the first coffee roasters manufactured by Diedrich Roasters, now located in Sandpoint, Idaho. I was not the first owner of this machine. By the time I acquired it, the old roaster had been through several fires and needed all of the tender loving care that I could give it. I typically roasted 15 lb loads in 15 to 18 minute roasting cycles, depending upon what flavor profile I was trying to achieve with a particular bean.
Before I started roasting commercially, I tried several methods of home roasting, including stovetop poppers, hot air poppers, and a homemade bbq drum roaster for use with a propane grill. After I sold the coffeeshop/roastery, I knew that I wanted to continue roasting at home for personal use, but wanted something more dependable and versatile than previous homeroast equipment.
I was searching for new techniques on the internet when I came across the Corretto, which is a method employing a bread machine and a heat gun. I have a friend in NYC who loved roasting with a heat gun, a chopstick and a dog’s steel waterbowl. Training the heat gun on the bowl of coffee beans, he used his other hand with the chopstick to stir the beans for an even roast. Burnt beans is a bad thing. However, the chopstick stirring never appealed to me. I wanted to automate that process.
Enter the Corretto.
Green coffee beans are placed in the bread machine’s loaf pan. I typically roast with about 3 1/2 cups of raw beans. After locking the loaf pan back into the bread machine and selecting the dough setting, starting the bread machine stirs the beans. Now I can use the heat gun (set to its highest temperature and fan setting).
The first thing you will notice in the photo above is all the chaff that is released in the roasting process. This is not an activity that you want to try on your kitchen island (or anywhere indoors). I’m roasting in an old pole shed with the overhead door open for ventilation. Yes, ventilation. That’s the second reason not to roast indoors. There is a lot of smoke in the last couple of minutes of the roasting cycle.
During the 12-15 minute roasting time, the beans turn from green to yellow to tan to brown to dark brown. If roasting continues, the beans will turn oily and black. I generally stop a few snaps into what’s called second crack. At first crack, the beans make a sound similar to popcorn. At second crack, the beans make a sound similar to Rice Crispies with milk just added.
Today, I am going a little darker than normal. After the beans have finished roasting, it’s very important to cool the beans rapidly. I use an old cardboard box with a hole in the top and on the side, a metal strainer and a shop vac.
The shop vac is in sucking mode. Leaf blowing mode would make a big mess. In cold winter temps, the beans cool in about 90 seconds. During the summer, cooling can take 2-3 minutes. I’ve used that same cardboard box for several years.
The general rule of thumb that I use for freshness in coffee is that green beans will keep fresh for a year or two, a week or two for roasted beans, and a day or two for ground beans. Today’s coffee was sourced by Royal Coffee and sold to me by Burman Traders. With the coffee roastery, I could have a pallet of beans delivered to me by truck for about $75 from Cafe Imports in the Twin Cities. Beans were between $2-4 per pound and shipped in bags up to 152 lbs. Now I pay between $5-8 per pound for 5 lb bags that Burman lets me pick up for free at a Madison, WI pickup spot.
Please comment if you have any questions or would like to discuss this topic further.