There are many photos of coffee bean roast color charts on the Internet. Is there a particular chart that's favored by our home roasters (or professional roasters, for that matter?) I have a professional photo printer that does a great job reproducing colors accurately.

The reason I ask is that I'd like to do a better job of assessing and keeping track of the roast level of the beans I buy. I think this will make the dial-in process more efficient and will allow me to keep track of the roast levels favored by each roaster.

Right now I evaluate the color of beans from memory, without using a standard reference. I realize that color doesn't completely define a roast, and that comparing color by eye using photographs isn't 100% accurate, but I'd at least like to try using a chart to be more systematic in comparing roast levels.

I don't think any chart is going to give you the best possible idea of roast color. Yes they will give you a rough idea if you are familiar with the bean. In order to get a precise measurement of color and therefore roast development I would advise getting an agtron coffee roast analyzer.

Since you're coming at it from the consumer end, and not the producer (roaster) I don't think it will be of much help.

If you were roasting, then color (agtron or other) might help you only because you'd be seeing the SAME exact coffee many times and could keep it consistent.

But as a consumer, you're far better off just noting bean expansion, texture, seams etc..Each different bean is going to have a different color that cannot be correlated to roast level, due to its own specific makeup. One color on one roast will mean something entirely different on another bean.

Ellejaycafe wrote:In order to get a precise measurement of color and therefore roast development I would advise getting an agtron coffee roast analyzer.

At my level of commitment to preparing coffee, I'm OK with spending a few hundred dollars for a good measurement device (I have a VST refractometer and a Scace), but I'm not prepared to spend thousands of dollars. I'd only do that if I was starting a commercial roasting operation. I haven't been able to find a device that can measure coffee bean color that's within my budget for such a device, which is why I asked about a chart.

So, you must already know about the Tonino, right?
http://my-tonino.com/

+1 I should have provided this link in my post. It's affordable and a great tool.

TomC wrote:But as a consumer, you're far better off just noting bean expansion, texture, seams etc..Each different bean is going to have a different color that cannot be correlated to roast level, due to its own specific makeup. One color on one roast will mean something entirely different on another bean.

Fair enough. I had a feeling this might be the case, but not being a roaster I had to ask.

What I'm really after, of course, is some indication of relative solubility so I can pick a starting dose, grind setting and extraction method that best suits the coffee without going through a ton of beans. This is takes several iterations when using standard extraction techniques, but when you add the potential for using other techniques, like flow/pressure profiling, sous vide or microwaving, etc., the number of permutations increases and it can take a lot more iterations (and beans) to find the best combination of technique and parameters.

Put more plainly, often I stare into a new bag of beans and wonder whether I should pull it with standard technique or jump right away to flow/pressure profiling or some other technique that's more likely to fully extract the coffee.

As a rule of thumb, I usually start with standard technique for espresso blends because they tend to be roasted darker (though not always.) Same goes for SOs that are specifically designated as roasted for espresso (again, not always -- some roasters go really light with their SO espressos). I usually start with flow/pressure profiling if it's coffee roasted for brew or one that has no specific designation (a number of roasters, like Counter Culture and Compass Coffee Roasters don't specify the recommended brewing technique, and CCC goes so far as to say that any technique can be used), or if it comes from a roaster that I know roasts espresso really light (e.g., George Howell.)

But as the above implies, simple rules of thumb don't always apply. Recently I pulled the Nicaragua Misael Olibera Sauceda from Temple Coffee Roasters. It's not specifically designated as roasted for espresso (they do have espresso roasts, which tend to be on the darker side.) My wife brewed it in our Technivorm and thought the coffee was really terrific. I wanted to see how it would pull as espresso and, since the beans were somewhat on the darker side, I used standard technique. It pulled great -- well enough that I didn't think it was worth exploring the use of flow/pressure profilng, which would be my normal starting point for beans not specifically roasted for espresso. My decision was based just on eyeballing the beans and it struck me that maybe I need a standard reference for roast level.

Some of the initiative for this came from Kaminsky's discussion of solubility in this video, which I'm sure you've seen:

https://www.youtube.com/watch?v=a-YI50dUC7g

He talks about longer roasts being more soluable, and near the end he talks about roasting components of a blend to have the same solubility in order to get an even extraction.

This got me to thinking that I should try to correlate bean color with solubility, and thus the best extraction technique to start with, and that I needed a standard reference against which to compare color.

But I gather you're saying this will ultimately lead to a dead end.

SJM wrote:So, you must already know about the Tonino, right?
http://my-tonino.com/

No, I didn't know about this device! This is what I was looking for -- an objective measure of color at an affordable price.

But if I understand what Tom is saying, it's not going to help me predict solubility.

Comments?

I somehow misunderstood that you are "not a roaster".
I don't think the Tonino is what you need under those circumstances.
Not that it won't tell you something, but not something that is really critical unless you are comparing roasts.
IMO

My bad.
Susan

On further review, I see that the color has to be measured after grinding, and the grind setting is dependent on the technique I'm using For example, I grind much, much finer for flow/pressure profiling than for standard technique.

It doesn't seem like the grind setting would affect the color reading (does it?), so I guess I could just pick an initial setting by guessing (as I do now) and then measure the color to select the best brewing technique to start with -- i.e., stay with the grind I just used or switch to the grind I use for a different technique. In other words, the first grind might be sacrificed.

At a minimum, though, it would allow me to track color levels for different products from different roasters, and to correlate them with extraction techniques and yields. That seems worthwhile.