So it begins... home-made drum roaster

[gonzob]

I decided to take the plunge.

I saw the "baby roaster" and decided I could make one of those, so I did. Then I ordered a CS sample pack, which arrived today, and Ive just completed my first roast.

Heres the gear:

The complete roaster setup:


The drum:


The stand:


The drum is modeled on the baby roaster and is made from 3" copper tube with copper end-caps. The handles are attached to the drum with furniture leg mounts. I made a bayonet-style locking mechanism for the drum lid.

I tried the Ceja de Selva first. I put 150g in the drum, but on completion I found the expansion almost filled the drum, so next time Ill use a bit less. The beans couldnt move too well at the end, so I got a slightly uneven roast.

The beauty of the system is that If I want to make a bigger drum, all I need to do is cut a longer length of tube and fit the end-caps!

I tried the coffee in my new Presso. Great.

Gonzo

[Bosco_Lever]

Re: So it begins... home-made drum roaster

Fantastic!
Well done.
As a suggestion, you should drill three holes in the lid end (if that makes sense), to vent the heat and smoke. This way you will have a visual aid to your roasting. The baby roaster has three small holes in the removable handle. I am sure someone can post a picture for reference.

[shapeshifter]

Re: So it begins... home-made drum roaster

Love it, its very like the idea we had as well until I decided to stay with the popper

[Andy]

Re: So it begins... home-made drum roaster

Excellent work, I love it.

You might even consider putting a 10mm "paddle" in there to help tumble the beans over. It might also help produce a more even roast.

Well done Gonzo.

[gonzob]

Re: So it begins... home-made drum roaster

Thanks, all.

The lid has 3x3mm holes already. they are difficult to see on the photo. I was thinking of making them a bit bigger so I could see the colour of the beans more easily, but I think Ill persevere for a few roasts. I like the idea of keeping the roast contained.

Andy, I couldnt see if the "baby roaster" had something to turn the beans over. Ill give it a try - maybe silver-solder a small "shelf" on one side? I was careful to keep the inside free of sharp edges so as not to damage the beans, but I dont know if thats a problem or not.

Gonzo

[Andy]

Re: So it begins... home-made drum roaster

so as not to damage the beans

Beans are pretty tough, a paddle turned by hand certainly wont break them.

The gotcha with a flat bottomed drum is in theory you could just slide the bed of beans causing some to be in contact with the drum for a long time and some to never contact the drum.  That is why people shake those type of devices every minute to change the contact beans.  Instead, a simple paddle should turn them over evenly for the duration of the roast.

On commercial drums its a spiral, that turns the beans over during roasting and pushes them out (corkscrew-esk) at the end of the roast when the door is opened.

Considering you can tip your drum upside down at the end of a roast a spiral wouldnt add anything.  A single or even three strips in your design should keep the beans moving well though.

Then you can get more high-tech and look at maybe putting them on an angle to move the beans away from the cooler endcaps.

I think the Gene Cafe has one of the best action drums, it tumbles the beans over and rolls them end to end with the off-axis drum.  A really clever idea and should produce the most even bean to drum contact across a batch.

There are lots of things you can try as you continue the journey to better coffee!

[lindsayra]

Re: So it begins... home-made drum roaster

Hi Gonzob,
Great work, love it.

consider putting a 10mm "paddle" in there

maybe silver-solder a small "shelf"

Why not swing your "shelf" off a couple of those hefty Philips head screws you used for fixing the endcap and bayonet for the lid lock?

Lindsay

[gonzob]

Re: So it begins... home-made drum roaster

OK, what an I doing wrong?

I got a sample pack of Mexican Yeni Navan, Colombian Volcan Galeras, Ethiopian Ghimbi, and Peru Caja de Selva

Ive roasted them in the roasting drum, generally getting 1st crack at about 9mins and getting about the right colour at about 16mins. I havent been able to detect a second crack, the 1st crack just seems to get louder, then tapers off, and then it looks like getting too dark. I cool with colanders in a fan breeze. I havent got a CS colour gauge, but it looks to be about 9 or 10. Theres a bit of variation, bean to bean.

Anyway, thats what Ive been doing. The problem is the taste. Im getting not a lot of crema (certainly less than I get with Supermarket Beans, Vittoria, Harris), the taste is not sweet, and there aint much body. The aroma both of the beans before grinding and the coffee after brewing is nowhere near as strong as SBs. Altogether a bit of a let-down.

Im thinking Im not roasting for long enough, because there are still some smells like weetbix/cattle-dung. However, I dont want charcoal.

Suggestions please. Keep em nice

Gonzo

[Koffee_Kosmo]

Re: So it begins... home-made drum roaster

Have you added vanes for better mixing yet?

Here is a guide to roast level
http://www.sweetmarias.com/roasting-VisualGuideV2.php

KK

[SniffCoffee]

Re: So it begins... home-made drum roaster


Hi Gonzo

How long are you waiting between roasting the beans and using them?

You should probably let the beans degas for at least 3 or 4 days before using them. Stick them in a bag with a one way valve, and each morning squeeze the bag and smell what comes out of the valve...the smells and flavours should become more apparent after the beans have rested.

If you like try some beans each morning from the same roast and see how the flavours change. I generally organise my roasting so that the beans rest for about a week before I start using them.

cheers

Sniff

[Beanz.]

Re: So it begins... home-made drum roaster

Hi Gonzob A great no nonsense roaster that would be very practical when on the road travelling and camping. Where did you pick up the copper tube and end caps ? Most of the copper tube I have seen has been smaller diameter

[gonzob]

Re: So it begins... home-made drum roaster

KK - no I havent added a vane yet. Im doing more shaking! Helpful link. Thanks

Sniff - Yes, Im letting them rest in glass jars which I open once a day. Others comments suggested that I could use the beans from a drum roaster right away, but I soon learned that I couldnt. Ive let them sit for 4+ days.

Beanz- The tube and endcaps come from Reece plumbing. Any plumbing supplies will have them. Unfortunately, copper aint cheap these days.

Any thoughts on the crema?

Gonzo

[Dimal]

Re: So it begins... home-made drum roaster

Gday Gonzo....

Just from your profile timings above, Id reckon you could reduce the heat a little at the start of the roast in an effort to stretch out the time to the start of Rolling 1st-Crack - Say to around 12 minutes, give or take....

When you hear 1st-Crack start to roll, reduce the heat a little more so as to prevent running directly into 2nd-Crack and aim for about 3-5 minutes from the end of 1st-Crack to the first few snaps of 2nd, at which time you could dump the batch and cool. Keep notes on what happens with each roast batch until such time as you get more of a feel for the process itself and the idiosyncrasies of your particular setup (which is great by the way 8-))....

Youll get there mate, its a learning process and coupled with your new roaster, it may be a little steeper curve than that for a Popper for example. Once you get a handle on it though, youll be churning out some wonderful coffee....

Stick with it....

Mal.

[taco]

Re: So it begins... home-made drum roaster

I love the simplicity of this design, and I think that once Ive gotten the hang of popper roasting Ill be looking at knocking one of these up too and cooking over the wok burner of my BBQ.

Not having done any metal work since high school, Im not sure of the tools required.
Did you buy the threaded rod already in correct lengths or did you cut it? If you cut it yourself is there a trick to not screwing up the thread?
Most of the construction looks simple enough, screws and rivets. Any particular reason you screwed the base cap on but used rivets for the handle mounts?
What tool did you use for creating the bayonet style locking mechanism for the lid?

Sorry for asking so many questions :s

[Randy_G.]

Re: So it begins... home-made drum roaster

If you cut it yourself is there a trick to not screwing up the thread?

To cut any threaded part (even bolts and screws), run the nut onto the part first, cut the part to length, grind or file the end smooth with a beveled edge, wire brush the cut end )with a power tool preferably), and then run the nut off over the cut end to clear the threads, Wire brush again if necessary.

Another tip: you can make a die to clear the threads by taking the correct size nut, and using a jewelers saw or small file, cut two or three slots inside the nut through the threads. Heat the nut up to a deep red and drop it into some powdered sugar. The sugar will carbonize the surface a bit.