Rotisserie roasting (electric oven)

[Wushoes]

Re: Is Zinc dangerous?

Today I used a Zinc plated steel hasp and staple to close the hatch on the drum for my roaster.

I did a bit of research and found that Zinc melts at approx 419 deg C, Now I know roasting will only say reach temps of 250....say 300 max. Is this enough to cause concern?

I did a roast with it today and it seems fine. Perhaps brass or a pure steel with no zinc plating for corrosion protection is a better option?

[JavaB]

Re: Is Zinc dangerous?

I did a bit of research and found that Zinc melts at approx 419 deg C, Now I know roasting will only say reach temps of 250....say 300 max. Is this enough to cause concern?

I did a roast with it today and it seems fine. Perhaps brass or a pure steel with no zinc plating for corrosion protection is a better option?

Wushoes,

Zinc is only really a concern if heated to a temperature at which it fumes - like arc or oxy welding- and even then it produces flu like symptoms which last for only a short time (except on Fridays where the effects are more profound - the symptoms lasting into Monday - requiring extra time "off work")

If you are heating to that sort of temperature - you would have a lot more to worry about than zinc fumes!

[robusto]

Re: Rotisserie roasting (electric oven)

The only cautions Ive come across with zinc, or rather, zinc-plated material, is not to breathe the fumes when welding. Ive experienced it, and it is not exactly neutral or pleasant, but very fumy and unpleasant.

-Robusto

[Wushoes]

Re: Rotisserie roasting (electric oven)

All is good in the world then =]

My world at least

[Wushoes]

Re: Rotisserie roasting (electric oven)

Hmm- I wonder if we should worry that much about thew 15 min? I remember Peter saying that they roast for 30 min at the last bean day. Do we roast just the outside of the bean if we rush it too much?

My hottop is more like 22 min to 2nd and the Gene is also giving much better results slowed down rather than rushed through in 15 min.....

Yes I remember chatting to Pete and he said he takes his roasts to 30 minutes. Then again, the bag of coffee I received with my Mazzer (gratis) was very very oily...perhaps an experimental batch of Venez Estate.

With the electric oven I found that roasts hitting second crack in more than 20 minutes displayed greater signs of tipping and ended up tasting baked. Roasts that were under 18 minutes generally tasted better. Perhaps a slower ramp up and lower temperature up to 1st crack is the key. However, with a rpm of about 3-5 in the electric oven (compared with 40+ rpm in commercial roasters), youd think that there would be more conduction heating than convection heating since the beans spend more time in contact with the drum than in the air. Perhaps this causes more scorching and baking of the beans or maybe the temperature is too high for such a low rpm. I havent run enough roasts or profiles to provide any conclusive results either way. Im currently running a bunch of profiles to test this out so should have some results in the next few weeks.

However, sorry wushoes for hijacking your thread. Let us know which profile you find best.

My 2 roasts so far have been successful in my very limited experience. No scorching...or "baked" taste...not sure what you mean there Matt. I only have 2 or 3 beans that have the smallest of divots on them. Maybe if you have the time one day and Im down your way I can get you to have a taste of my coffee.

[MattG]

Re: Rotisserie roasting (electric oven)

My 2 roasts so far have been successful in my very limited experience. No scorching...or "baked" taste...not sure what you mean there Matt. I only have 2 or 3 beans that have the smallest of divots on them. Maybe if you have the time one day and Im down your way I can get you to have a taste of my coffee.

Coffee roasted too long at too low of a temperature can taste baked. On the taste wheel (http://www.sweetmarias.com/tastewheel1.jpg) it is classified as bakey, flat, dull. However, I have been able to get roasts with roast times up to 26-27 minutes with incredible flavours and no baked taste by keeping the ramp up to 1st crack slow.

Feel free to drop by anytime; I cant promise to have the best palete.

[Wushoes]

Re: Rotisserie roasting (electric oven)

Off topic: Hows the renovations going...all done?

[MattG]

Re: Rotisserie roasting (electric oven)

My 2 roasts so far have been successful in my very limited experience. No scorching...or "baked" taste...not sure what you mean there Matt. I only have 2 or 3 beans that have the smallest of divots on them. Maybe if you have the time one day and Im down your way I can get you to have a taste of my coffee.

Come to think of it, maybe it was the sherman tank of a drum I gave you that prevented heat getting into the drum. Looks like you wisely went with your own design. Good to see it working.

Off topic: Hows the renovations going...all done?

Still have a lot to do... for quite a while yet. Probably wont get to rennovate the bar for another 12 months. Putting Lino in the bar and recarpetting the entire upstairs over the next few weeks.

[Wushoes]

Re: Rotisserie roasting (electric oven)

Yep...I even made a little hatch on the side of the drum like yours....which I had been meaning to do since I started making the drum myself. Works a charm. Aluminium drum works well....except for getting beans stuck =[

[dBndbit]

Re: Rotisserie roasting (electric oven)

Anybody care to educate an ignorant yank? Whats a milo tin? Does it have a metal lid?

Im also murdering a helpless rotisserie oven to make a coffee roaster. Thanks very much for all the great ideas here. Big help. Best creativity (or worst desperation) Ive seen! Next Im planning to slap a rotisserie motor on the side of a deep fat (vegi/peanut oil) fryer. Without the oil.

[JavaB]

Re: Rotisserie roasting (electric oven)

dBndbit,

Hi and welcome to CoffeeSnobs....

A milo tin is basically the same as an instant coffee tin..... it is all tin plated steel including the press fit lid.

Rotisserie ovens are fine for roasting but I wouldnt try a deep fat fryer. They are designed to rapidly pass heat to the oil..... no oil in the fryer and the element will get too hot..... and pretty soon you will have element melt down (just the same as using an electric jug without any water in it.....)

[robusto]

Re: Rotisserie roasting (electric oven)

A milo tin in this neck o the woods is a barbecue rotisserie roaster drum. ;D ;D ;D

After drilling hundreds of holes in one, and rivetting some L-section aluminium bits as stirrers, its been serving me nicely as such for a couple of years.


--Robusto

[nunu]

Re: Rotisserie roasting (electric oven)

A Milo tin is very similar to the large Quik tins (strawberry or chocolate doesnt matter) you see at Costco.

[Boldor]

Re: Rotisserie roasting (electric oven)

Here you go, courtesy of Nestle

[dBndbit]

Re: Rotisserie roasting (electric oven)

Thanks. I thought maybe the Milo can was unusual, like a removable lid. I got a big tomato paste can thats the perfect length and diameter to maximize the bean output of my oven. As long as it doesnt have any coating on the inside, I might be perfect. Ive noticed some cans have what looks like Teflon or some cheaper plastic on the inside.

Also, Ill make sure the thermostats are in the right place to prevent overheating the fat fryer. But whatever happens, it should be fun to watch.