Cast Iron Pot roasting…gas fire roasting

[colombiasmoothbean]

Re: Cast Iron Pot roasting…gas fire roasting

which I bet was no cause for complaints from our grandparents

There are many mechanical things of the past that work perfectly, and we often think that by adding a technology overlay we improve things. What is the added benefit should be the question. This solution was for the lack of decent beans where I live at the moment. I never thought I could replicate the result I get with my Hottop back home.

Lately I have been thinking I may actually be rather close. Here some thoughts:
-The roast is not as even, but then when I break some of the darker beans they look the same on the inside. So maybe there is something going on that makes some beans darken more on the outside (ie the direct heat transfer from gas flame>cast iron>bean).
-I now have found a routine where the roast takes 21minutes to completion of C1. At that point I actually hear a bit of matchstick breaking...so some C2 must have started.
-I now agitate slower. Once the beans expand and vent moisture they bind more together and the bean mass seems to turn over quite consistently.
-the ideal roast weight seems to be 310g. At that volume the beans dry out evenly, the smoke vents nicely and I can see I see the beans change..

To your comments:
-the agitator is actually quite ingenious. It is not symmetrical and this provides mixing action that results in the bean mass being turned over. I did add a bit of wire to the centre as some beans got left out of the mixing action there.
-when this thing was made there was no espresso as we know it today. That this thing allows me to have a very respectable coffee is amazing. And, it is portable, cheap and will not wear out.

Seems a neat way of getting a pretty good roast result. My most recent supply of CS green beans has arrived and I am set for quite some time!

[robusto]

Re: Cast Iron Pot roasting…gas fire roasting

Very nostalgic-looking apparatus which I bet was no cause for complaints from our grandparents. The problem is that the stirrer only appears to agitate horizontly, moving beans from one area of the pan to another on the same horizontal plane of equal heat.

If you could change that so the beans also agitate from top to bottom that should improve evenness.

You could also try adapting the handle to take the chuck of a battery drill --saves manual labour.

-Robusto

[colombiasmoothbean]

This is my 3rd roast with my early 20th century German makeshift cast iron roasting ‘pan’, which was designed for roasting on a coal/wood ‘Aga’ type stove. Cost to date: roaster $65 + camp type gas stove $40 + colander $10 = $115

My question is this: Is there something peculiar to roasting on a fire? What I mean is the following:
-I started roasting with a popper. Max 40 gram, in effect roasting on a fluid bed of hot air. I guess since corn pops at 350 F, that was the temperature pretty much from the start. The beans roll about in the hot air and all is very uniform. No slow heating up, no profile of temperature, just even heat and the roast was done in 12 or so minutes.
-then (lucky me) I got the Hottop roaster. 250g, ability to try roast profiles, and repeat them. Roasts take 21-23minutes, VERY even beans. The beans are not in direct contract with heat, tumbling in the drum. Rapid cooling in the tray. Lovely. But I could not take the Hottop to Cyprus.
-Now the Cast iron pot. The last roast took 23 minutes. I had washed the beans, and dried them a bit in a towel. At 8min they started browning, C1 from 15-19 min, C2 starts at 22 min, all beans out in the winnowing colander at 23 min. What I get is this:
>small number of spoiled burned beans
>maybe 2% of beans that are burned on the outside but NOT inside
>a really nice tasting roast. Possibly as nice as with the Hottop.

So, can I possibly expect to achieve ‘evenly roasted’ beans or is this just how it works out with roasting on fire? After all, the heat transfer is by direct contact of the beans with the heated cast iron pot. With the best of even agitation it may not be possible to prevent some beans getting externally scorched. And, the small number of burned beans is probably ok.

Any suggestions on how to improve the evenness of the roast?

Here are some photos of the last roast: