roasting green coffee beans

[berryst]

Re: roasting green coffee beans

I've been thinking of making coffee bean roaster by making a stainless steel cage and putting it on the BBQ rotisserie. Its one of those Costco stainless BBQs. I just don't use the rotisserie and it sleeps in the garage.. Your thoughts?

[nissanneill]

Re: roasting green coffee beans

berryst,
Getting green beans over here is a real problem and roasting them in an oven would be a little challenging, mainly with the temperature control.
This would also apply to a gas fired bbq. There are numerous sites that specialize in roasting beans, many using a heat gun in an older breadmaking machine, others with bbq's and the really serious proper roasters.
Instead of using your bbq, why not try the same as Rastys and make the most of the reduced heat of your oven. You would need to make a door that would allow a shaft through to a rotiserie but the temperatures would be OI think a little more stable and consistent than a bbq.
Food for thought.

Neill

[fornax hominus]

Re: roasting green coffee beans

While I have not roasted in a gas bbq in a pinch I have roasted in the firebox of our Jotul woodstove with most of the smoke going up the chimney but with the same situation that you would face ie: basically only extreme bottom heat .
I wold try putting a pizza stone or ceramic pottery shelf on the grill to diffuse and even out the heat... of course it will be trial and error till you work out your timing .I clear a path in the flames and coals to roast my coffee .. I imagine it's in the 700-800f range and it takes about 12 mins. Not being able to see your coffee while it finishes means a lot more listening [for the final ''crack''] and timing the roast you want
Rasty's design of an octagonal basket is well worth a look at.
happy roasting,
tim
oh boy! 2'' of wet snow on the mountain this AM ... Way too early!!

[countryboy]

Re: roasting green coffee beans

Any updates to this thread? Rastys? Fornax? Others?

Thanks,

Pete

[heliman]

Re: roasting green coffee beans

How do you monitor colour changes, cracks and remove the husks when roasting in a WFO or other oven type device?

The hot air corn popper method I have used addresses all of those elements.

[fornax hominus]

Re: roasting green coffee beans

Hi, I wrote this bit on roasting coffee for another [gasp!] wood oven site.. it covers a lot of the questions.
cheers,
tim
Roasting coffee beans in wood fired oven

[Lacehim]

Re: roasting green coffee beans

G'Day. I followed nissanneill's post here from a coffee forum. I've roasted coffee a few times in a device I made myself, using 2 sieves and a pole. It worked well but got pretty tiresome! For me roasting in my woodfired oven isn't about consistency, it's about having fun, maybe introducing some of the amazing WFO smell and taste into the beans.

I purchased a drum off a coffee forum a few months ago, the holes are maybe a bit big (6mm), but my intention is to build a frame for it to slide in to the oven. I hope this link is okay with the mods, but this is the drum (photos are form the seller who was using it on a BBQ) Woodfired Oven Roaster - Crema Coffee Forum

I'll use a bucket with a fan and sieve to cool the beans, it has a little door to drop the beans. The drum came with a rotisserie motor which is more than fast enough, and I've got a PWM to slow the motor down but allowing the motor to still turn the drum.

I roast my own beans on a KKTO at the moment in 250 - 600gm batches. It works very well, and I currently own a Quick Mill 0996 Achilles & a Vario grinder, so I guess you could say I love my coffee journey!

The pizza are great too by the way, and our woodfired oven is by far the best purchase I've made ever! I just wish it was stop raining here so I could use it more often!

I'm glad others are trying the same thing! I thought I was totally mad attempting to roast coffee on my WFO! lol.

Oh, and I would roast with the door open. You'll get heat from the floor and the fire. My intention was to put the fire to one side, probably when there are no flames, just red coals. For coffee roasting you need heat around 250degC. I roast to second crack, and the only issue I think I'll have is coasting it slowly between 1st and 2nd. I thought possibly pulling it out of the oven slightly to reduce the temp.

[Laurentius]

Re: roasting green coffee beans

berryst,
Getting green beans over here is a real problem and roasting them in an oven would be a little challenging, mainly with the temperature control.
This would also apply to a gas fired bbq. There are numerous sites that specialize in roasting beans, many using a heat gun in an older breadmaking machine, others with bbq's and the really serious proper roasters.
Instead of using your bbq, why not try the same as Rastys and make the most of the reduced heat of your oven. You would need to make a door that would allow a shaft through to a rotiserie but the temperatures would be OI think a little more stable and consistent than a bbq.
Food for thought.

Neill

Hi Neill,

Why would it be a problem?? Coffee is grown and sold in Australia, didn't you know that? Some of it is pretty Damn good. It no problem roasting coffee in your WFO, a wire basket on a long pole with a lot of shaking and listening to the beans can get you a better cup, than most outlets that buys pre-roasted pass it prime beans

[nissanneill]

Re: roasting green coffee beans

Laurentius

Getting green beans over here is a real problem and roasting them in an oven would be a little challenging, mainly with the temperature control.

Since building an lpg roaster, I am convinced that to get consistency in roasting, you need to have consistency and reliability, something that a WFO doesn't provide. Plenty of heat, too far away to hear the cracking let alone see the bean colour and it is really hit and miss.
I have joined a couple of coffee forums and now realise that roasting is a very scientific process that you need to have total control over if you want the best from your chosen beans rather than just turn beans dark brown to enhance their flavour.
I built a rotiserie roaster for the oven but have never used it, now I built an lpg roaster from an old lpg tank and included a thermocouple beside the roasting beans. I have roasted 6 lots and the consistency is spot on and I have total control over the temperatures.

Coffee is grown and sold in Australia, didn't you know that? Some of it is pretty Damn good.

Yes I am well aware of it but is pretty average!!! I'd rather pay for better coffees at less profit as the Australian coffee although in it's infancy is quite expensive when compared to many other countries produce.
I now buy my beans from thttp://www.beangreen.com.au/ and very happy with their choice, price and service.

Cheers.

Neill

[Lacehim]

Re: roasting green coffee beans

Hi Neill,

I was about to suggest Beangreen, they are fantastic and have great service. Spend over $50 and get free delivery, and I can buy from 1kg up.

I still want to give my drum ago, I think the WFO roaster will be a fun experiment! You have most of the workings already there, just buy some cheap green (BG usually have $8 specials) and give it a go. Worse case senario is that you hit 3rd crack!

Consistency isn't everything when your homeroasting. Well that's my opinion anyway. I roast without a DMM, and my roasts turn out great most of the time just using my senses, and when they don't I learn something. Home roasting is all about fun, and it's good to experiment and build roasters (like you LPG one).

The WFO is a great heat source and because the beans are moving it should be consistent enough in my eyes. I'll be happy to post up my efforts soon, because I hope to have my finished in a few weeks. Just building a frame out of bits and bobs.

Your roast in the tray looked good, but in your close up your beans looked a bit oily. Are you taking them well into Rolling second crack? If so you might want to pull them a bit earlier. I pull mine just as it hits 2nd crack and the thermal mass of the beans will keep the beans cracking as you pull them and cool. Also what are you using to cool them? A bucket and a fan from Bunnings works great.

Also I hope you don't mind but I linked to your roaster piccies here, I've never seen a roaster built out of an LPG bottle and I though the folk on my favorite forum would love to see it. Here's a link if you want to join and comment yourself. LPG roaster - Crema Coffee Forum

Also if anyone is interested here the website for the KKTO that I use regularly Home It uses a Turbo oven as a heat source, and a motor to turn the beans. Works very well, and the designer has thought of everything. The chaff is taken away to the bottom pot, so minimal mess, and easy to replace parts!

Thanks also I had put this project aside and this has given me a kick along in the right direction to getting it finished

[Laurentius]

Re: roasting green coffee beans

Hi Neill,

I've being home roasting coffee for a few years now and agree with what you're saying. If a person want to give it a try, in a very short time he will be able to do a decent roast in his WFO, all he has to do is allow the oven to cool to coffee roasting range. Now you sounds like me, obsessive. One of those who have gone up the ladder from, cast iron pot, modified popcorn popper, me to my behmor 1600, and you that home made monstrosity of your.

[nissanneill]

Re: roasting green coffee beans

Hi Laurentius,

that home made monstrosity of your.

That unique mechanical marvel is not a monstrosity, it is a work of art. When roasting, I note the temperatures on commencement, every 30 seconds and when first and second crack appears. I now use this data to improve on previous roasts with my version of a log. By playing with time and different temperatures, you can emphasise different subtle flavours within your roast.


Lacehim

Consistency isn't everything when your homeroasting.

Sorry mate but I disagree. Rather than just having fun and producing a drinkable roast, you will want more of the better outcomes, especially when you have much better quality beans. Like you, I tried my first 2 roasts with $7/kg Indian beans which tasted quite nice, the $13 Kenyan AA Dorman beans are much stronger (but I prefer a darker rather than a mild lighter roast). Now I am blending my beans (roasted ones that are strong with those that are mild), getting a little more out of my lot!

Your roast in the tray looked good, but in your close up your beans looked a bit oily.

Spot on BUT not burnt! In my notes on my roasting profile, I will reduce the time by 30 seconds!
At our pizza fests, we always finish now with home roasted espresso coffees which go down a treat.

Cheers.

Neill

[Laurentius]

Re: roasting green coffee beans

Hi Neill,

Yes, it is a work of art, how long from concept to finished product? Is there a reason that you do not denote the time between 1st crack and second crack and time stopped. Smoke as a criterion?? That could be caused by an error bean in the wrong place of chaff burning, have you considered that. Roasting until surface oil appear is not a good thing, a sheen is different. Can you ramp up or slow down your temperature to modify the profile?

[UtahBeehiver]

Re: roasting green coffee beans

Piques my interest. I enjoy a good espresso but after the WFO, I dare not start another project for a while until I get some honey do's done.

[nissanneill]

Re: roasting green coffee beans

Laurentius

Yes, it is a work of art, how long from concept to finished product?

Once I collected the old bottle, outdated 1997, it only took a half day to cut the bottle in halves, (ensuring that it was totally empty and not likely to explode nor catch fire, but if I were to do it again, rather than cut it through the centre weld, I'd cut it around 40mm higher), weld on the hinge brackets, using a hole saw, cut holes in the base for air ventilation and to protrude the gas ring, cut and fold the basket and handle then bend, drill and weld the basket supports. The only other task was to drill and tap the top brass ex-valve to hold the thermocouple, (this was later lowered to beside the rotating basket.

Is there a reason that you do not denote the time between 1st crack and second crack and time stopped.

There seems to be no distinct lull between 1st and 2nd crack, so that is where time and temperature control is important. By putting in the side of the basket a patch of woven stainless steel wire mesh to visibly see the bean colour is so important because if I lift the lid, then a lot of the heat escapes and becomes uncontrollable!

Smoke as a criterion??

This is my best indication of roast done! The first sign of the blue smoke means all over and cool beans immediately. There seems to be no smoke from the burning chaff that I can detect but see the ash falling out of the basket and through the gap of the 2 bottle halves.

Can you ramp up or slow down your temperature to modify the profile?

That is why the recording and time/temperature determination for my ideal roast is so important for consistency. The making of a new drum/basket with larger holes and thicker material, 1.6mm (16g) allows more chaff to escape and burn, also easier to weld and hinge, BUT being heavier, draws more heat out of the dome and takes a little effort to maintain the required.desired temperature.
I can remove the basket from the roaster and dump the contents into a large thick aluminium roasting pan in less than 20 seconds and then float the lot in a shallow sink of cold water, bringing the beans to room temperature in a minute or so. Just looking for a small battery (or even 12v motor to rotate the basket/drum, but unlike a rotiserie, I want at least 30-60 rpm rather than the 3rpm average of rotators. A windscreen wiper motor is looking good but I would prefer a small battery unit rather than a 240v transformer reduce to 12v set up.

Cheers.

Neill