Roaster's Notes

Roaster Arrives (2003)
After the painful wait, the roaster arrived in December, all the way from Turkey. The truck pulled up to our old kiwifruit Packing Shed. The driver mentioned that the load is one big chipboard crate weighing in at 350kg, and he wanted to know where the fork lift is. I looked at the crate and realized, there is no way we are man handling the crate off the truck. Fortunately I remembered the neighbour up the road had a tractor and also has a small Kiwifruit orchard like ours, I was sure he would have fork lift parts for his tractor to enable him to move around the kiwifruit crates. I gave him a ring and shortly he drove up in his ancient tractor and we proceeded to gently transfer the crate off the truck and into the shed.

Once I removed the chipboard walls off the crate I had a perfectly assembled roaster sitting on a wooden pallet. The trick was to get it off the pallet. I could lift one end at a time, and slowly I swiveled one end off the pallet, I levered it up so my 10 year old son, Michael, could pull the pallet out, then I let it down as gently as I could. And there it has stayed.

The next thing to arrange was the gas supply. The gas fitter took a long hard look at the roaster and the turkish/english specs and decided that 9Kg bottles were not going to do it, so we now have two 40Kg bottles sitting outside nicely piped into the roaster. The gas fitter mentioned that we may need some fluing for the smoke and gas fumes. I thought we should try a roast first.


The Test Roasts
We had 10Kg of test beans to flavour the drum and also to practice on. My oldest son Jonathan (12 years) was fascinated by the whole thing and had demanded to be involved in any roasting. So Jonathan and I studied the roaster's instructions and the little I had found on the Internet about the roasting process and then prepared for the first roast.

There was a thermometer on the flue from the drum, and the instructions suggested 200C was the desired temperature to reach before letting the beans into the roaster. We fired up the roaster, waited until 200C and then Jonathan dropped 5Kg of the beans in, using the swing arm that allows the beans to drop into the drum through the top of the flue.

All eyes quickly turned to the drum as the beans tumbled by the observation window. The gas fitter was still there and was keenly watching developments. Then all of a sudden flames appeared at the side of the roaster and then burners promptly stopped. The burners had tripped off for some reason, the beans were still roasting from the heat of the drum. We reset the burners and fired them up again. That worked for a couple of seconds and then stopped. The gas fitter scratched his head and started checking his pipes and the pressure to the roaster.

We managed to finish the roast to a decent colour by resetting the burners a few times, and then the gas fitter set about discovering where the problem was. The roaster had certainly been working well before the first roast, but now was just not firing up. Then I realized, I had assumed that Jonathan had released the swing arm for the beans back to open the flue, but he hadn't. Our only problem was that the flue was blocked by the bean intake plate and so the burners had no oxygen.

We were now ready for the next roast.

We fired the roaster up to 200C again. Jonathan released the beans and swung the arm back again. The burners keep going. The beans started to cook, quickly. In fact within 1.5 minutes the beans reached their first crack. This wasn't what I had expected, the first crack was meant to happen after 3 or so minutes and the whole roast was meant to take about 8-10 minutes. But I patiently waited, after about 3 minutes there was the beginnings of a little smoke, and the beans were actually quite brown. Still I waited, after 5 minutes there was alot more smoke and the beans were quite black. Only then did I order Jonathan to turn off the burner and prepare the cooling tray. Events then took a turn for the worst and there appeared an awful lot of thick blue smoke that even started to escape from sides of the roaster, the beans were oily and sticking to the observation window where they were slowly sliding down.

We opened the bean release lever releasing alot of smoke and some very sad beans.


The First Real Roast
We chose the Colombian beans for our first real roast. We again heated the drum to 200C, released the beans into the drum, and then turned the burner off.

This seemed to work well. The beans were not burning, but after 5 minutes they also hadn't cracked. We fired the burners up again, took them through the first crack. I wanted to wait a good couple of minutes after that, but the beans were quickly darkening under the burners and we released them after quite a long roast of about 9 minutes. The beans were very dark but not burnt. We decided they were worth salvaging and so we put them aside to package up as our first dark roast.

Interestingly they were very popular with our friends who had espresso machines, and not very popular with plunger users.


The Light Roasts
After the test roasts and the Colombian roast I was very nervous about over roasting the beans. The next two roasts were Kenyan and Sumatran beans, both of which I tried firing up the roaster to 200C and then stopping the burners at the first crack. These roasts were still happening too fast, and I pulled the beans out only a few minutes into the first crack.

By this stage I decided the starting temperature of 200C was too high. For the next roast, which was the Brazilian beans, I started the roast at 175C, which helped a lot, but I still panicked and pulled the beans out shortly after the first crack.

On tasting the beans, I liked the strong dry winey taste of the Kenyan. I felt the Sumatran had nothing to offer, it tasted OK but had no bite, it seemed empty. The Brazilian was awful, it was strong in body and acid, but had an dirty earthy aftertaste and smell that didn't appeal to me at all. I was very surprised by this. I had read the Brazilian is normally the base of many espresso blends.

A friend wanted some more dark roasted Colombian beans for Christmas. And I wanted to experiment with lowering the starting temperature to 160C. The roast went very well. It took three minutes for the first crack, We turned off the burners, and waited for the crack to pass. We then panicked again and pulled the beans out shortly after the first crack. We had a very nice light to medium roast, but not the dark roast our friend had wanted.

On tasting the Colombian roast it was good but very mild. I tried mixing it with the Samatran, as I really didnt know what to do with the Samatran, and I was very pleasantly surprised. The cup had a very full bodied flavour, nice croma, and the Samatran added a slight perfumed fragrance. The blend still didn't have much kick to it, but with a touch of Kenyan it made a very fine plunger coffee and a mild expresso coffee.


Getting The Roast Right
I still needed to do a dark roast, so I tried the last of the Brazilian beans. I hoped that the first Brazilian roast was just a bad roast and not the fault of the bean. I again started the roast at 160C, everything went very smooth, turned the burners off at the first crack, and waited. The beans slowly got browner and after several minutes the second crack was just starting. I removed the beans when they were into the second crack. I had achieved nice dark roast and I felt in control through the whole process.

Unfortunately on tasting the Brazilian had now even stronger earthy tones, and I decided it was not the bean for me.

After Christmas I received my samples of PNG Sigri and Guatamala SHB beans. I was ready to try something different.

I choose to roast the Sigri first. I decided to try roasting it to a medium dark roast. Not as dark as the Brazilian before, but dark none the less, as I still didnt have a satisfactory dark roast to offer. I removed the beans from the drum just as the second crack occurred.

The Sigri bean is very similar in appearance to the Colombian, it is quite big and slender. But upon tasting the Sigri was amazing. It had a rich and full body with just the right amount of acid. There was no strange aftertaste. A simply wonderful coffee. I can't see any need to blend it.


Well, that is as far as I have got and I still have a lot to learn and a lot of coffee to try. But it has been even more fun than I had hoped.

Andrew Bevin