1kg home roaster

[matt_Hellyar]

Re: 1kg home roaster

sorry not much closer, Ill take a real close up next roast.

[happihappi]

Re: 1kg home roaster

ok, the laser wasnt ideal and its got me thinking about TC probes and how to get one into my bean mass.

Laser tep scanners and readers need time to take a stable reading... Thus unless a high end unit with very fast responce times.

You should also try and take temp as close to the subject as possible Most infra-reds will be reading the surface area at a ratio of 10:1. Therefore at 50cm away, youre reading a circular surface area with an approximate diameter of 5cm.  

[matt_Hellyar]

Re: 1kg home roaster

yeah, I did get reasonable readings when I pointed it directly at beans on my sample spoon, but it is much nicer having a probe giving me constant readings instead of grabbing samples every few seconds to take readings.

laser is off the roasting team, he may come in handy around the home though.

[Dimal]

Re: 1kg home roaster

Gday Matt,

Pretty decent roast for a new roaster mate [smiley=thumbsup.gif]..... Excellent stuff.

Notice in your photos a few beans that appear to be showing signs of very slight "tipping". This could be due to the initial steep gradient prior to First Crack(FC). If you could adjust your gradient down a little, such that Rolling FC starts nominally at 12 minutes or so, this will probably overcome it. Ditto what the other guys have already mentioned re stretching out the time to the start of Second Crack(SC).

All in all though Matt, it comes down to what the coffee tastes like in the cup and that is always the final arbiter. Lots of very enjoyable experimentation ahead of you mate..... ;D

Mal.

[matt_Hellyar]

Re: 1kg home roaster

thanks Mal,

tonights 2 roasts.
the first is mine and the second is a mates beans.

during both of these roasts I was using a new exhaust system that I set up today, I was very happy with it for both temp control and smoke removal.

I post pics of it in a sec

[matt_Hellyar]

Re: 1kg home roaster

BTW the red dots are the first roast I did with the probe

[matt_Hellyar]

Re: 1kg home roaster

Notice in your photos a few beans that appear to be showing signs of very slight "tipping". This could be due to the initial steep gradient prior to First Crack(FC).

Thanks for the tip on tipping Mal, the above roasts were done before I read your post. Ill have a go at a gentler start next roast

[matt_Hellyar]

Re: 1kg home roaster

here is a close up of the first roast I did tonight, my mate took his home so no photo.

and also a pic of my new exhaust setup.
it runs into my cooling box which if you havent read earlier posts, has a kitchen exhaust hood twin fan in it. sucks hard.
so I put a lid on my cooling tray to direct all the suction to the exhaust and then when cooling i cover the exhaust hole.

works great.

[matt_Hellyar]

Re: 1kg home roaster

BTW I would be happy to send some coffee for cupping to a few people if interested. Id like the feedback (and helps to get rid of some roasted coffee so I can roast some more)

[stuartgrant]

Re: 1kg home roaster

Hey Matt,

Thanks for the close-up(s). The second photo is one of the most even roasts Ive seen on coffeesnobs - cant fault it whatsoever. Being Costa Rican, theyd be wet-processed, which makes more a more even roast, but seriously, they look awesome.

BTW - at the top of the photo is a bean with whats called a divot. This is where, just before or into SC, the beans are creating so much of their own heat that they lose a chunk off their surface. It CAN be considered a roasting fault, since it CAN be indicative of entering SC with too much heat in the roaster. But it can also just happen when you take the beans into SC at all. I suspect if you were able to flatten the curve on the graph on the approach to SC, that would be beneficial. Maybe delay SC (which I assume was around 12-12.5mins?) by 30-60 seconds?

I can see what Mal was talking about referring to possible tipping in the first photo (the not-so-close-up :P), but in my opinion its probably okay. Ive often noticed a stage of the beans expansion around SC where they take on quite a mottled appearance. Thats what Im seeing in the first photo. Of course, it could be minor scorching/tipping, too. But it looks like you sorted it out for tonights roast.

Im following this thread closely because Im currently designing a 1.0-1.5kg drum roaster... problem is that Im stuck in Bulgaria until next April! Until then, your build is giving me a great deal of vicarious enjoyment!

Cheers
Stuart.

[matt_Hellyar]

Re: 1kg home roaster

Thanks Stuart, look forward to seeing your roaster in April

sipping on some of last nights roast (pictured on page 2) now. I can taste the difference between this and the red dotted line, but I dont have the tasting experience to explain it... It is better that is for sure.

[matt_Hellyar]

Re: 1kg home roaster

once again happy to post some to any willing person with cupping experience.

[matt_Hellyar]

Re: 1kg home roaster

Just a few more shots of my new exhaust setup.

you can see how I cover the bean cooler when roasting and then cover the exhaust when cooling

[stuartgrant]

Re: 1kg home roaster

MH,

does the exhaust manage to pull any/much chaff out? In either case, where does the chaff end up?

Like the dual-purpose, single fan approach - works well.

Cheers,
Stuart.

[matt_Hellyar]

Re: 1kg home roaster

I think it is pulling the chaff out, Im not seeing caff in my beans anymore, but these dont have a lot. Ill let you know once Ive roasted some real chaffy beans.

I am planning to build some kind of mesh catcher in the box to catch the chaff. at the moment it is just landing in the box on the fan housing. will vacuum it out soon (dont want chaff fires in cooling box)