Intro: Do It Yourself Hand Cranked Coffee Roaster.
As a Colombian I love coffee, but roasting it has always been a pain in the neck. The other day while I was watching videos I saw an antique roaster being used and I knew I had to make one like that to make roasting easier. I went to the room where I keep my scrap and found everything I needed to make it right at home, so here it is guys. Enjoy it!
Step 1: Materials.
The materials I used are as follows:
- A 3/8" construction rod which was getting rusted in my backyard (2 meter long).
- A piece of aluminum pipe where the rod will fit loose (for the crank). To be honest, I'm not too good at aluminum sizes, so just look
at the pictures please.
- Two tuna cans.
- A scrap stainless steel sheet that was left from another project (30 Cm X 20 Cm).
- A couple of washers.
- A short piece of thick wire about 1/8".
Step 2: Making the Roaster Body.
To make the body of the roaster we need to roll the stainless steel sheet lengthwise, so that it will fit inside the tuna cans. I used different sizes of PVC pipe to achieve that, beginning with a 3" pipe, and ending with a 1/2" pipe and doing it by hand. For the roaster to be very effective and roast the beans evenly, I made a bend in the inner part of the rolled sheet, so that the beans are shaken and change positions while you are cranking. You can clearly see the bend which is only 9 or 10 mm long.
For the tuna cans to fit inside the crank and actually get cranked, we need to make some 3/8" holes right at the center of them, and with a small triangular file or a 1/8" file, make an off centered hole like the ones you see on the pictures. You will understand what I mean when you see the crank. (Sorry if the pictures are not very clear, but you can make out the holes).
Once your holes are made, your roaster is ready fit the two tuna cans on each side of the rolled sheet to make a can with two caps. Now let's continue with the stand and the crank.
Step 3: Making the Stand.
To make the stand, with the help of my vise I bent the rod without cutting it, to the shape shown in the pictures. To make the hooks, just start hitting the tip of the rod little by little, releasing the rod in short steps, grabbing it on the vise and hitting it again.. This step is one of patience, but you will get it done I'm sure. To achieve a stand that will not be wobbly, I hit the base part of the stand to bend it a little, so that it would stand more like in 4 points rather than flat, as shown in the pictures.
Note: Make sure you measure the total length of the roaster before bending the rod, so that it will fit with a little slack between the two hooks.
Step 4: Making the Crank.
The crank is the only part where you are going to need some welding but just two dots. If you look closely at the bottom of the picture you will see the two pieces of wire welded to the crank.To make the crank just measure the length of the roaster and give yourself some space (two inches would be alright), to accommodate the crank on the two hooks with the roaster inserted in it (look at picture No 1) before you bend anything so that you have enough space and don't waste material.
After you have made the crank bend, at 7 cm, make another bend to fit the aluminum pipe, giving yourself enough room to freely grab the crank. I measured the pipe by grabbing it with my fist and leaving an inch on each side. Make yet another small bend for the pipe to stay in place.
Once your crank is bent, go to a close shop and have the two pieces of wire welded only at the center, not on the outside, because you want them to be a little shaky in order to absorb some of the pressure from the crank on the cans (look at the pictures to see where they are welded). On the last picture, you can see the washers in place without the roaster.
Note: The distance between the center rod and the crank should not exceed 7 cm, otherwise your hand will be hitting against wherever the roaster is standing. Trust your eye-balling abilities here, just like I did when I was bending the rod for the stand. Remember your rod is only 2 meters long. Before you weld the short wire that is close to the crank, insert one washer that has a 3/8" hole that will hold the roaster in place once it is all assembled for roasting. If you forget this step, you can always cut the washer and insert it later like I did, but it will look better if it is uncut.
Step 5: Assembling the Roaster.
To assemble the roaster, insert the rolled stainless steel sheet in one of the cans and then the other one to make a "can". After this, insert the crank through the can holes (this is where the offset holes will allow the welded wire to pass through the can). Insert your other washer and check if the roaster will rotate freely on the stand. You may have to cut the wires until they stick out of the cans and barely hit the washers and still be able to crank the roaster this is a trial and error step, until you get them at the right length.
Step 6: Roasting Coffee.
To roast coffee in your roaster, take the crank with the roaster in it. Remove the roaster from the crank. Remove any of the tuna cans and fill the roaster with coffee beans no more than 3/4 of its capacity. I personally recommend 1/2 its capacity for a good quality of coffee. After you fill the roaster, assemble it and put it over your stove or range top.
First turn on the heat in high for about 3-4 minutes and then lower it to medium. In my experience at roasting coffee, I have noticed you get a richer coffee flavor when you roast it at medium heat. Crank constantly until you start listening to the beans crack. Your coffee is almost ready. At this point you see smoke coming out of the roaster. Continue cranking until the smoke is more continuous and at this point turn off the heat. Remove from the stove using your crank handle, remove the upper tuna can using a pot holder and turn your beans in a container to cool off as quickly as possible. Your coffee beans are roasted.
Note: Before you use your roaster for the first time, it is a good idea to put it on the stove for at least 15-20 minutes and crank it a couple of times to burn any toxic materials coating the inside of the tuna cans, usually plastic, which might be toxic.
Here's a useful link to help you learn a little more about roasting coffee. http://www.youtube.com/watch?v=d3ZA5Eg9wfg
I hope this project helps all the people out there who like good coffee and who enjoy doing things themselves. Oh! and have a cup of good coffee on my name.