Something hard to grind with a hand grinder, hahahaha.

What answer should one give? Nobody buys an agtron reader to tell you what's the roast level.



My last acquisition, having fun with 1 kg.

Good Karma - Ethiopia Uraga washed 2019 crop, roast level bright or filter roast. When you have chaft on the beans it means its light.

There are so many parameters by which a green bean responds to roasting that I find using color reference scale (Agtron) to determine a standard completely wrong. Characteristics such as Age, region, bean variety, humidity, and drying method contribute to the way a bean starts to color and roast.

It would be nice to have a standard by which to determine a light roast but color shouldn't be one, IMO it should be in relation to the timing before/during/after first crack. Perhaps a time measurement standard?

Personally I characterize the depth of my own roasts in terms of three numbers that together tell you a great deal about how well-developed a coffee is and what sort of flavors you can expect:

1. Overall roast time
2. (Finish temperature) - (First crack start temperature)
3. DTR

If you want to make it four numbers you can also use dry/ramp/dev times in addition to the delta between first crack start and finish temps. This doesn't really tell you any more about how "dark" the coffee will taste but it does tell you more about the balance you can expect between maillard and caramelization flavors.

But it is hard to get this information from commercial roasters because profiles are often kept as proprietary secrets.

Color is an okay proxy if you measure both exterior and ground coffee color. The exterior alone can be very misleading if used across roasts with different total roasting times, as there can be variations in how much heat had reached the bean centers.

Perhaps there's two questions here: 1) how to describe a roast to a barista or coffee drinker; 2) how to describe a roast to another roaster.

For a barista or coffee drinker, the two agtron readings are fairly good. The ground agtron is going to tell you how the sugars, caramels and dry distillates will taste. The difference between the whole bean and ground agtron will tell you how baked and maillard tasting the coffee is, and how reduced the acidity will be in a long but light roast. If I were a barista and had the two Agtron readings, I'd have a very good idea how to dial in the coffee.

For another roaster, the idea is to reverse engineer the flavor (especially if his roast of the same bean sucks in comparison ). Here I think a lot of information is in order. Even identical profiles of bean temperature on different roasting gear can create different roasts (since environmental temperatures may differ). So all these wonder ratios people like to talk about are incomplete, since they are roast device dependent. If I were reverse engineering, I'd still like the two Agtron numbers, since I know how to get those on my gear. But I'd need more -- I can get the same two Agtron numbers for a lower ET/lower charge roast as for a higher ET/higher charge roast; and these would taste rather different.

There you go, just bring the money:



https://syncfo.com/english


If agtron is not enough for you, then you have this. In roasting there is desired a really uniform roast, in-out. A big difference in agtron in/out means a bad roast profile, bad coffee, bad roaster (machine). The thing on Instagram has a really high difference between in/out agtron = it sucks.

A uneven roast from in-out means you are doing a cocktail with light/undeveloped coffee in the center, and well developed coffee outside. You pull more from one side than the other, so this just undermines the extraction.

Almico wrote:It might be fun to start a cinnamon roast thread and see what develops...or under develops

Check this one while you're at it.

Thoughts on Arabic (Gulf) coffee?

guydebord wrote:There are so many parameters by which a green bean responds to roasting that I find using color reference scale (Agtron) to determine a standard completely wrong. Characteristics such as Age, region, bean variety, humidity, and drying method contribute to the way a bean starts to color and roast.

It would be nice to have a standard by which to determine a light roast but color shouldn't be one, IMO it should be in relation to the timing before/during/after first crack. Perhaps a time measurement standard?

Agtron does not measure color: "Two samples can be the same color yet cup to different roast classifications. This effect reduces the resolution of analysis and can often produce erroneous results. The eye is subject to the same deficiencies and is additionally affected by perception variables, making accurate and repeatable assessment impossible.

To solve these problems the Agtron E20-CP and M-Basic/II use a very narrow band of near-infrared energy which is outside of the visible spectrum. This frequency is selected because it sees the development of chemistry as it effects cup character independent of color. Samples are evaluated both as whole bean and ground, with simple preparation. Using an Agtron makes it possible to evaluate and subsequently control both the degree and uniformity of roast."

https://www.agtron.net/Coffee1.html

yakster wrote:Check this one while you're at it.

Thoughts on Arabic (Gulf) coffee?

I read that thread and it's part of my interest is very light roasted coffee.

Denis wrote:There you go, just bring the money:



https://syncfo.com/english


If agtron is not enough for you, then you have this. In roasting there is desired a really uniform roast, in-out. A big difference in agtron in/out means a bad roast profile, bad coffee, bad roaster (machine). The thing on Instagram has a really high difference between in/out agtron = it sucks.

A uneven roast from in-out means you are doing a cocktail with light/undeveloped coffee in the center, and well developed coffee outside. You pull more from one side than the other, so this just undermines the extraction.

Would you mind sharing your wisdom with us? Just how do you roast coffee that light and get ground and whole bean measurements close. I would like to know specifics. Can you show us a very light roast profile you have done where the Agtron numbers came out close? Can you show us a profile that anyone has done where the numbers came out close? I can duplicate any roast profile. I'd love to learn and see this for myself.

Try a 395 convection oven for 12 hours -- light roast, even color, delicious --

I thought I heard the Geisen has a smaller delta.