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Thread: Roasting time - Popper

  1. #1
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    Roasting time - Popper

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    I have been roasting beans in a popcorn popper for about 2 months now and have been pretty happy with the results.
    I only roast 100g at a time and I usually have 1st crack start within at least 2-3 minutes and am finished within 4-5 minutes.
    After reading through this forum it seems most people seem to be roasting for about 10-15 minutes.
    Is my experience normal for a popcorn popper and am I missing out on some flavours by roasting so fast*.
    I have cut some beans up to inspect inside and they actually seem to be slightly darker inside than out so I am guessing that they are roasting all the way through.

  2. #2
    Sleep is overrated Thundergod's Avatar
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    Re: Roasting time - Popper

    Its possible to get longer roast times out of a popper.

    Which popper do you have?

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    Re: Roasting time - Popper

    You can increase roasting times with a few very simple low tech changes:

    1) use as long an extension lead as you can find and use more than one if you have them. There is a current drop due to the resistance that lowers the popper heat. Try this with your least favorite beans, as you may find that you cant even get to 2nd crack!

    2) use a fan on a double adapter blowing over your popper. This blows heat out of the popper and also uses more of the available current, so the heater gets less. It also give you some control on where your chaff goes. Ive experimented with using the original plastic top to channel fan blown air into the popper. I now just use a soup can chimney that I have cut down so that I just lose a bean now and then. I want it small to let the fan blow into the popper as much as possible.

    3) Use less beans. My popper will do 90 gms in 6 minutes and I can stretch that out to 9-11 minutes by going back to 50 grams. Yes, you need a lot of patience to get your roasted stash up to scratch! ;D

    4) Shake your popper in an up-down rotational motion to get the beans moving at the start, rather than stirring. This gets the beans away from the hot surfaces, mixes in cooler air and lengthens the initial heat up time.

    5) Once the beans will spin by themselves, experiment with tilting your popper. The benefit here is that you may be able to get better mixing of the beans. I tilt mine (about 30 degrees) so that the main mass is moving slowly and there is a gap down to the bottom of the popper on the high side. I can see beans coming off the bottom and being blown up to the top of the stack. This also allows some of the hot air to bypass the bean mass and blow out of the popper.

    I had a link to some research where these variations were proven with a stop watch and thermocouple, but I seem to have lost it. I have satisfied myself somewhat less quantitatively that they do work.

    Hope that helps! ;)

  4. #4
    Senior Member Lovey's Avatar
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    Re: Roasting time - Popper

    Gday shawty,
    80 grams is a more realistic figure for most (un-modified) poppers, so try dropping the bean weight slightly and see how you go.
    To add to TGs post, some poppers are definitely better than others out of the box, and some are easier to modify than others.
    Good luck with it.
    Steve.

    EDIT - Wannabesnob just pipped me at the post ;D.
    The use of a long extension cord is something that is popular in the USA as they a lower mains voltage than here is AUS, and does not have nearly the same effect over here. Another thing to remember with these sort of mods (reducing the input voltage) is that it not only redcuces the input voltage to the heater, it also reduces the voltage available to the fan, giving you a lower fan speed.

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    Sleep is overrated Thundergod's Avatar
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    Re: Roasting time - Popper

    Quote Originally Posted by 63757A7A757671677A7B76140 link=1236635991/2#2 date=1236666805
    1) use as long an extension lead as you can find and use more than one if you have them. There is a current drop due to the resistance that lowers the popper heat. Try this with your least favorite beans, as you may find that you cant even get to 2nd crack!
    I dispute this one.
    Reckon it doesnt apply in Australia.
    Ive tried using my 30 metre extension and it makes zero difference.
    (Lovey beat me to it.)

    Quote Originally Posted by 63757A7A757671677A7B76140 link=1236635991/2#2 date=1236666805
    2) use a fan on a double adapter blowing over your popper.
    Ive found that getting more cool air to the input vents of the popper works best.

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    Re: Roasting time - Popper

    Thanks a lot for your replies

    My popper is a Tempo - Model B32A1
    I was wondering if there was a way to reduce/control the heat while still keeping the fan speed (maybe a high watt variable resistor in series with the heater element)
    Interesting that doing less beans will increase time (must have something to do with the beans moving around more and letting the hot air escape out the top easier I guess???)
    The fan idea sounds great
    Am still interested to hear if such quick roasting times are bad for the bean quality in the cup

  7. #7
    Senior Member Lovey's Avatar
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    Re: Roasting time - Popper

    Gday shawty,
    I dont think that you could get a high enough wattage resistor to use in series with the heating element, they (the element) run at about 1000W (give or take a few 100).
    There are a few ways of getting longer roast times with a popper, ranging from cheap and easy to expensive and not so easy.
    Some methods that have been used include:-
    - making the intake holes on the bottom of the popper bigger. You could use a file or a small plastic grinding bit or a drill. From memory, this was one of TGs methods.
    - putting a fan underneath the popper to force cool air into it.
    - splitting the heater and fan circuits and having a controller to vary the temp and/or the fan speed. (This requires knowledge in relation to mains electricity and it can kill you if you mess up - standard disclaimer and warning ;)).
    Having less beans in a popper will increase the roast time (to a certain extent) due to having less bean mass to trap the heat and having more air flow.
    The conventional wisdom is to lengthen the time between 1st and 2nd crack, but you dont want to have the roast stalling due to a lack of heat.
    The easiest and best way to see if the roast time makes a difference is to try it and see. The only thing that matters, is that you enjoy the end product, whether that be a 3 minute or a 15 minute roast.
    Hope that helps,
    Steve.

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    Re: Roasting time - Popper

    Thanks Steve
    Just tried opening and closing the bottom while running the popper with a temp probe in place to see the difference in temp but nothing changed.
    To my surprise though the temp only reached 180C but when I roast I think it gets to about 220-230C
    I wonder if I am going to put a lot of effort in I might be better changing to the corretto idea as I have a breadmaker that hasnt seen the light of day in about 5 years.
    I have only been drinking coffee for about 2 months now as I didnt really like the instant I had previously tried, so Im not sure what a really good coffee tastes like. I just know that mine tastes reasonably good and that I seem to be drinking more and more.........
    Bought a Breville 800 and am already looking to upgrade

    PS. Just spent a very enjoyable weekend watching SW I-VI

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    Re: Roasting time - Popper

    Quote Originally Posted by 2C373E282B265F0 link=1236635991/5#5 date=1236678476

    My popper is a Tempo *- Model B32A1
    I was wondering if there was a way to reduce/control the heat while still keeping the fan speed (maybe a high watt variable resistor in series with the heater element)
    not sure if this will work on a popper but, you could try a dimmer switch from a "light" depending on the load" (watts) etc. you could wire one up into the power lead.

    building a triac contoroller might work better,

    but i am unsure how a popper heats .

    i use a triac on some homebrew gear to control a "hotwater" element not sure if it would work on the poppers

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    Re: Roasting time - Popper

    Yep, a high power triac dimmer works well. I got one from the UK to use on my popper, as I couldnt find anything local that could handle to power at an acceptable cost. Ive written about it on here before. You need to split the fan and heater circuits too, and use a seperate transformer for the fan. If you do a search you should find more info on how to do this. It involves dismantling the popper and re-wiring it, so beware that youre playing with 240V.

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    Re: Roasting time - Popper

    Quote Originally Posted by 6B404545290 link=1236635991/9#9 date=1236739762
    You need to split the fan and heater circuits too, and use a seperate transformer for the fan. If you do a search you should find more info on how to do this. It involves dismantling the popper and re-wiring it, so beware that youre playing with 240V.

    I had a laugh i forgot about the fan :) i was thkning of wiring it into the lead, but then the fan would (might?) slow down as well......

    for a good triac (build yourself) goggle, homedistiller and triac and read the threads on that forum. if your handy in the electrics area there is a simple build one with parts from jaycar etc. hope that does not break the posting rules ?

    i got to go find a popper and play

  12. #12
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    Re: Roasting time - Popper

    I wouldnt worry about trying to build a "dimmer" unless you just want to do it for fun. Lots of high powered dimmers are available for controlling QI or QH floodlighting and can be obtained mainly from venue lighting specialists or the people who supply their hardware...

    Mal.

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    Re: Roasting time - Popper

    Hey Lovey, Lilydale Vic is in Australia. I have increased my roast times with my old Black & Decker by about 150% on average using two long and inefficient leads as well as the fan. It works for me, dont know why it doesnt for you and Thundergod. I believe Ohms law expresses the theory. Constant voltage with increased resistance means decreased current..... less current at least in my B&D means less heat and longer roasts. As said, with all of my retarders going at once, some times I cant get to 2nd crack in 19 minutes, so I pull the roast anyway.


    TG, you may be right about more air flow but I dont want to modify my popper, so Ive looked at all non destructive methods instead. Id always recommend testing non destructive methods 1st before starting to hack. Theyve worked for me and are pretty easy to try.

  14. #14
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    Re: Roasting time - Popper

    Quote Originally Posted by 293F30303F3C3B2D30313C5E0 link=1236635991/12#12 date=1236763278
    TG, you may be right about more air flow but I dont want to modify my popper, so Ive looked at all non destructive methods instead. *
    I only got destructive to save time.
    I took it to the extreme to show the potential.

    However, if you have a Crazy Popper for example it can be as simple as raising it off the bench, as they sit very low and thus restrict the airflow.
    Secondly you can then aim a fan at the base to help get more cool air in.
    I even tried sitting my popper over a bowl of ice to get cooler air in.
    An alternative to drilling extra holes in the base, is to remove the base cover and replace it with plastic flyscreen or bonsai mesh; this is reversable.

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    Re: Roasting time - Popper

    The one downside to increasing roasting times is that I am likely to wear out my popper much faster

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    Re: Roasting time - Popper

    Wear out how?

    If it runs cooler it should last longer.

    I only did 27roasts in my popper before retiring it in favour of a corretto, so I cant say how long a popper should last.

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    Re: Roasting time - Popper

    Behmor Coffee Roaster
    Most of the increased roasting time techniques (bar the extension cord & the extra resistor/triac) dont reduce the power the fan or the heater are drawing. The heater isnt really running any cooler but the roasting chamber is just letting more heat escape or bypass the bean mass, hence cooler beans. The fan would also be running for longer.
    This isnt really much of a problem at the price you can buy a popper for, just an observation.



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