7 ms·

Roast Your Coffee In Two Stages – Now With OpenCV Tricks

35 points by boyter 13y ago

andrewcooke 13y ago
why is uneven roasting bad? if you want complexity in the coffee wouldn't a variety of roasts give variety / depth of flavours? is there some technical reason while all beans should be roasted the same?
- cpenner461 13y ago
  I've never really thought about this per se, but the first thing that comes to mind is that if things are uneven, it's generally more like some beans are burned and/or some aren't roasted enough. Either of those scenarios are going to produce undesirable flavors. I think the more common way to capitalize on a variety and depth like you mention is to roast different types of beans separately and then mix them. That said, there's a lot of complexity and variety just in single bean (or, single origin) roasts, differing levels of roasting bring out different flavors.
- mertd 13y ago
  Would you like half of your steak well done and the other half rare?
  - standeven 13y ago
    If you were to blend the entire steak together, would you notice?
    - anonymoushn 13y ago
      Yes, it would taste like a mix of rare steak and ruined steak
    - roel_v 13y ago
      I think it would. It's not like a piece of charred meat 'cancels out' a piece of cold, uncooked meat. If you were flavoring a batch of yoghurt, and 1/4 of it has 10% too much, and 1/4 10% too little, then yes. But for processes where the not-measured characteristics of the elements on the left side of the curve are different than those on the right, no.
    - deleted 13y ago
      [deleted]
  - cema 13y ago
    Steak is normally not ground, unlike roasted coffee beans. So there is no mixing. On the other hand, I know at least one coffee company that sells a mix of dark and light ground coffee (Melitta, in the US).
cpenner461 13y ago
I've been roasting my own beans off and on for several years, the quality is far better than anything you can get at the supermarket and even most coffee shops (unless they are doing their own roasting). Buying green beans is quite a bit cheaper as well, so you get the best coffee possible at the best price - win win! The air popper in the article is a popular low cost way to get into home roasting, but I started with just a heavy pot and lots of stirring, hard to keep things even. After a short while I built something pretty close to this: http://biobug.org/coffee/turbo-crazy/ http://biobug.org/coffee/turbo-crazy/ Still a lot cheaper than something like the Behmor, but able to easily roast 1/2 lb at a time. What I love the most about this is the analysis of the roast with opencv, will definitely be trying that for my next roast!
- chewxy 13y ago
  author here - boyter informed me that this was front page on HN. I'm actually seriously contemplating building a rig. I have 3 spare flashes for my camera and my table is a frosted glass table. It should be able to give uniform lighting to the beans for visual analysis.
  - cpenner461 13y ago
    Nice. Trying to think through that - would you be shooting the flash through the frosted glass to diffuse the light evenly?
    - chewxy 13y ago
      Yup. And possibly in a product tent or something. How much did it cost for your to build your version of the Turbo Crazy
      - cpenner461 13y ago
        It's been a few years but I think it was on the order of $100-150.
- bradly 13y ago
cornellwright 13y ago
I tried roasting my own beans once and it was a ton of work and made a lot of smoke. I just buy 5 lbs at a time from a place on the internet which roasts when I order and ships the same day. It tastes great and I don't have to deal with roasting.
- chewxy 13y ago
  Do you finish said 5 pounds (2.5kg) in about a fortnight or so? Just curious
- pinko 13y ago
  Link?
- 2muchcoffeeman 13y ago
  A unit like the Behmor comes with an after burner to burn the excess smoke. So you can home roast without the hassle these days. A project like this is fun if you also enjoy the tinkering, but given the markup on roasted beans, spending money on an appliance is very economical.
  - ScottWhigham 13y ago
    From my comment in this thread: If you go through a pound of coffee a week (which is likely for two adult coffee lovers), that means you'd have to spend almost an hour per week to roast your own coffee using the Behmor. It just depends on what "economical" means to you, I suppose. One hour per week roasting/managing is significant to me. If I could find a place that would sell me just-roasted beans in 5lb or more bags, it might be worth it. I paid $300 for the Behmor and I pay about $8-$10 per pound shipped for green coffee. If you said, "Scott - here are some great tasting beans that we'll roast for you right before we ship them, and they are $12 per pound", I would sell my Behmor. At this point I've learned most of what I'll learn about roasting coffee - now it's just a matter of spending that hour a week. If I could pay a company $2 per week to reclaim that hour though...
    - cpenner461 13y ago
tdicola 13y ago
There are lots of American small kitchen appliances that pull more than 1100 watts, including kettles. Most outlet circuits are rated for 15 amps so it's not uncommon for some appliances like toaster ovens or vacuums to use 1800 watts. I think the reason most Americans don't own an electric kettle is that tea isn't nearly as popular as coffee, and most folks use a dedicated drip or single serve coffee brewer.
- chewxy 13y ago
  Yup. It's also 13A in UK. I'm using 10A as a rough guide - mainly to illustrate the power differences between AU and US. The post has now been updated to reflect your comment. Thanks
JasonCEC 13y ago
If anyone here is interested in improving their home roasting, check out our services for Quality Control and Flavor Profiling [1]. I'd be happy to set you up a free account as a home roaster, and I think feedback from the HN community would be really helpful! [1] www.Gastrograph.com
ScottWhigham 13y ago
I loved this - this is why I love HN. Although roasting the beans in my oven would terrify me - the chaffe could so easily catch fire, couldn't it? I own the Behmor - I'm rather new to it (< 50 roasts). I'm happy with the purchase however I would caution anyone interested that (a) there's a massive learning curve (as OP points out), and that (b) even though it is marketed as being able to roast 1 pound of coffee, you will only really get a light-to-maybe-perhaps-kind-of-medium roast if you put a full pound of coffee in the drum. I only learned this after going through about 10 pounds of coffee (~20-30 roasts). I like a really dark roast - what I learned is that I can only roast 10 ounces at a time with the Behmor. Check out the top-rated review on Amazon - the guy says he can only roast 7-9 ounces at a time. After looking at $800 roasters, I'd still buy the Behmor if I was new to this and wanted a roaster. But here's the thing: to roast 10 ounces of coffee takes about 35 minutes - you have a 15-22 minute roast followed by a 12-13 minute cooling cycle. If you go through a pound of coffee a week (which is likely for two adult coffee lovers), that means you'd have to spend almost an hour per week to roast your own coffee using the Behmor. And this roast - there's about a five minute time period in the latter/end part of the roast itself that has to be attended. So you start your roast, come back 10-12 minutes later, wait for the cues you need, and then you can go on with your life. And you know what isn't great? The Behmor's temperature sensor will shut the unit down if it's cold outside (like below 30 degrees F). When it's cold, you'll have to get your roast prepared indoors, then take it outside, and start the roast. And that five minute period where you have to watch your roast? Let me tell you - it sucks to have to monitor a roast outside in 16 degree weather! That said, after roasting my own, it's almost unfathomable to me at this point to want to quit using the Behmor and go back to someone else's roast. I've enjoyed the learning curve.
- cpenner461 13y ago
  Wow that seems like a very long time (especially on the cooling side). Using my Turbo Crazy setup (see other comment here), I hit second crack in about 10m (which I'd like to get pushed out to about 12m I think, but the temp control on my convection oven is not very precise). For cooling I dump the beans into a 2 sided perforated oven pan (I can't find an exact link, but imagine 2 of these that attach together: http://www.amazon.com/dp/B002KE5OLY/ http://www.amazon.com/dp/B002KE5OLY/) and shake it gently over a fan, they're cool in about 2-3 min. I figure on about 15m per half pound of coffee. FWIW I've never had chaff catch on fire, and it seems to me that my setup is probably cranking a hotter/more direct heat than an oven would. But yes - roasting in the cold stinks - and yet I still do it as well. :) On the plus side, that cooling time drops to a min or so when it's 30F!

35 points by boyter 13y ago

why is uneven roasting bad? if you want complexity in the coffee wouldn't a variety of roasts give variety / depth of flavours? is there some technical reason while all beans should be roasted the same?

cpenner461 13y ago
I've never really thought about this per se, but the first thing that comes to mind is that if things are uneven, it's generally more like some beans are burned and/or some aren't roasted enough. Either of those scenarios are going to produce undesirable flavors. I think the more common way to capitalize on a variety and depth like you mention is to roast different types of beans separately and then mix them. That said, there's a lot of complexity and variety just in single bean (or, single origin) roasts, differing levels of roasting bring out different flavors.
mertd 13y ago
Would you like half of your steak well done and the other half rare?
- standeven 13y ago
  If you were to blend the entire steak together, would you notice?
  - anonymoushn 13y ago
    Yes, it would taste like a mix of rare steak and ruined steak
  - roel_v 13y ago
    I think it would. It's not like a piece of charred meat 'cancels out' a piece of cold, uncooked meat. If you were flavoring a batch of yoghurt, and 1/4 of it has 10% too much, and 1/4 10% too little, then yes. But for processes where the not-measured characteristics of the elements on the left side of the curve are different than those on the right, no.
  - deleted 13y ago
    [deleted]
- cema 13y ago
  Steak is normally not ground, unlike roasted coffee beans. So there is no mixing. On the other hand, I know at least one coffee company that sells a mix of dark and light ground coffee (Melitta, in the US).

cpenner461 13y ago

I've been roasting my own beans off and on for several years, the quality is far better than anything you can get at the supermarket and even most coffee shops (unless they are doing their own roasting). Buying green beans is quite a bit cheaper as well, so you get the best coffee possible at the best price - win win! The air popper in the article is a popular low cost way to get into home roasting, but I started with just a heavy pot and lots of stirring, hard to keep things even. After a short while I built something pretty close to this: http://biobug.org/coffee/turbo-crazy/ http://biobug.org/coffee/turbo-crazy/ Still a lot cheaper than something like the Behmor, but able to easily roast 1/2 lb at a time. What I love the most about this is the analysis of the roast with opencv, will definitely be trying that for my next roast!

chewxy 13y ago
author here - boyter informed me that this was front page on HN. I'm actually seriously contemplating building a rig. I have 3 spare flashes for my camera and my table is a frosted glass table. It should be able to give uniform lighting to the beans for visual analysis.
- cpenner461 13y ago
  Nice. Trying to think through that - would you be shooting the flash through the frosted glass to diffuse the light evenly?
  - chewxy 13y ago
    Yup. And possibly in a product tent or something. How much did it cost for your to build your version of the Turbo Crazy
    - cpenner461 13y ago
      It's been a few years but I think it was on the order of $100-150.
bradly 13y ago

cornellwright 13y ago

I tried roasting my own beans once and it was a ton of work and made a lot of smoke. I just buy 5 lbs at a time from a place on the internet which roasts when I order and ships the same day. It tastes great and I don't have to deal with roasting.

chewxy 13y ago
Do you finish said 5 pounds (2.5kg) in about a fortnight or so? Just curious
pinko 13y ago
Link?
2muchcoffeeman 13y ago
A unit like the Behmor comes with an after burner to burn the excess smoke. So you can home roast without the hassle these days. A project like this is fun if you also enjoy the tinkering, but given the markup on roasted beans, spending money on an appliance is very economical.
- ScottWhigham 13y ago
  From my comment in this thread: If you go through a pound of coffee a week (which is likely for two adult coffee lovers), that means you'd have to spend almost an hour per week to roast your own coffee using the Behmor. It just depends on what "economical" means to you, I suppose. One hour per week roasting/managing is significant to me. If I could find a place that would sell me just-roasted beans in 5lb or more bags, it might be worth it. I paid $300 for the Behmor and I pay about $8-$10 per pound shipped for green coffee. If you said, "Scott - here are some great tasting beans that we'll roast for you right before we ship them, and they are $12 per pound", I would sell my Behmor. At this point I've learned most of what I'll learn about roasting coffee - now it's just a matter of spending that hour a week. If I could pay a company $2 per week to reclaim that hour though...
  - cpenner461 13y ago

tdicola 13y ago

There are lots of American small kitchen appliances that pull more than 1100 watts, including kettles. Most outlet circuits are rated for 15 amps so it's not uncommon for some appliances like toaster ovens or vacuums to use 1800 watts. I think the reason most Americans don't own an electric kettle is that tea isn't nearly as popular as coffee, and most folks use a dedicated drip or single serve coffee brewer.

chewxy 13y ago
Yup. It's also 13A in UK. I'm using 10A as a rough guide - mainly to illustrate the power differences between AU and US. The post has now been updated to reflect your comment. Thanks

JasonCEC 13y ago

If anyone here is interested in improving their home roasting, check out our services for Quality Control and Flavor Profiling [1]. I'd be happy to set you up a free account as a home roaster, and I think feedback from the HN community would be really helpful! [1] www.Gastrograph.com

ScottWhigham 13y ago

I loved this - this is why I love HN. Although roasting the beans in my oven would terrify me - the chaffe could so easily catch fire, couldn't it? I own the Behmor - I'm rather new to it (< 50 roasts). I'm happy with the purchase however I would caution anyone interested that (a) there's a massive learning curve (as OP points out), and that (b) even though it is marketed as being able to roast 1 pound of coffee, you will only really get a light-to-maybe-perhaps-kind-of-medium roast if you put a full pound of coffee in the drum. I only learned this after going through about 10 pounds of coffee (~20-30 roasts). I like a really dark roast - what I learned is that I can only roast 10 ounces at a time with the Behmor. Check out the top-rated review on Amazon - the guy says he can only roast 7-9 ounces at a time. After looking at $800 roasters, I'd still buy the Behmor if I was new to this and wanted a roaster. But here's the thing: to roast 10 ounces of coffee takes about 35 minutes - you have a 15-22 minute roast followed by a 12-13 minute cooling cycle. If you go through a pound of coffee a week (which is likely for two adult coffee lovers), that means you'd have to spend almost an hour per week to roast your own coffee using the Behmor. And this roast - there's about a five minute time period in the latter/end part of the roast itself that has to be attended. So you start your roast, come back 10-12 minutes later, wait for the cues you need, and then you can go on with your life. And you know what isn't great? The Behmor's temperature sensor will shut the unit down if it's cold outside (like below 30 degrees F). When it's cold, you'll have to get your roast prepared indoors, then take it outside, and start the roast. And that five minute period where you have to watch your roast? Let me tell you - it sucks to have to monitor a roast outside in 16 degree weather! That said, after roasting my own, it's almost unfathomable to me at this point to want to quit using the Behmor and go back to someone else's roast. I've enjoyed the learning curve.

cpenner461 13y ago
Wow that seems like a very long time (especially on the cooling side). Using my Turbo Crazy setup (see other comment here), I hit second crack in about 10m (which I'd like to get pushed out to about 12m I think, but the temp control on my convection oven is not very precise). For cooling I dump the beans into a 2 sided perforated oven pan (I can't find an exact link, but imagine 2 of these that attach together: http://www.amazon.com/dp/B002KE5OLY/ http://www.amazon.com/dp/B002KE5OLY/) and shake it gently over a fan, they're cool in about 2-3 min. I figure on about 15m per half pound of coffee. FWIW I've never had chaff catch on fire, and it seems to me that my setup is probably cranking a hotter/more direct heat than an oven would. But yes - roasting in the cold stinks - and yet I still do it as well. :) On the plus side, that cooling time drops to a min or so when it's 30F!