Grain coffee moisture tester

[peter]

Upshot...  a question from the peanut gallery, if you'll indulge me...

What do you hope to gain from knowing the moisture content of your green coffee?

[jspain]

I just purchased a grain moisture tester on eBay to try out on coffee. I think that the calibration is the critical factor on whether this works on corn, or soy beans, or whatever you have...but you have to calibrate using a known sample of the target grain/bean/seed. I bought this for the ridiculous price of $14.00 plus shipping. It is not new, and sold for around $200.00 new. I put some greens I had laying around, and I got a reading of 12%. This could be right, or it could be wrong. I wouldn't know because I don't have a control sample. Anybody know where I can buy greens of a known moisture content? Would love to see my $14.00 investment pay off  !

upshot,

Take the greens to your local grain elevator that buys grain from farmers. All grain must be the proper moisture before storing in the elevator so to not spoil. My guess is they would test the greens as a favor and no cost. I grew up in the ag business.

[Ascholten]

jspain, I may be wrong but the testing machines I believe are highly calibrated to the specific grain, ie what may work well on wheat would be way off on coffee, as it would on corn as an example too.

out of curiosity I wonder if you say took 100 grams of beans and heated them to say 170 for a few hours to drive the water out of them, then weighed them if that would be semi accurate as to moisture content?  You wouldn't want to cook / roast them as other chemical reactions in that process would I am sure burn off other stuff besides water.  You may even get away with 10 grams if you had a sensitive enough scale, like a reloading scale maybe.

Aaron

[upshot]

Upshot...  a question from the peanut gallery, if you'll indulge me...

What do you hope to gain from knowing the moisture content of your green coffee?

Hi Peter,

What I "hope" to get, and what I expect to get are two different things. What I expect to get is quantitative information regarding a variable that contributes to the final result of what is in the beverage. As with any agricultural food commodity, proper management of moisture content along the supply chain is critical to ensure quality, and having quantifiable information regarding it is never a bad thing. Even if all one ever sees is that every potential purchase made is from a selection of beans whose moisture content falls within the acceptable range. This is called accountability, and also peace of mind.

What I "hope" to get is a correlation between bean mass density, moisture content, and roast profile that results in the fewest possible surprises. I do not know if that will happen or not, but willing to explore.

I like that you, earlier in this thread, proposed measuring the volume of a sample of beans and establishing a correlation between weight / volume and moisture content. My method is a derivative of this, but one in which moisture content is known, so that a correlation coefficient will be established for any bean type. Again, this is my hope. I am not naive to think this is a given, but again...willing to go down this road because this is how one perfects one's craft. I am not a follower, so I have to endure repeating things that perhaps others take for granted based on trusting what they are told. I am also not a whiner. If things go badly, I own up, and because the former characteristic, I can blame no one but myself.

upshot,

Take the greens to your local grain elevator that buys grain from farmers. All grain must be the proper moisture before storing in the elevator so to not spoil. My guess is they would test the greens as a favor and no cost. I grew up in the ag business.

That's an excellent idea. I don't live very close to any grain elevators, but a short day trip would put me in the heart of California's central valley where grain elevators are as common as gas stations! Thanks again for the suggestion!

Thanks again to you too Peter

Kindly,

Upshot

[upshot]

Problem solved! Just visited a local roaster who gave me a 300g sample that he tested on the spot using one of the testers that looked quite similar to the one in the link at the beginning of this thread. The sample tested at 11%. I brought it home and put it in my tester and got 15.6%. Using the adjusting feature of the tester, I reset the reading to 11.00, and should be all set to go!

As to the discussion of tracking moisture content, I can now feel confident of where these numbers are when developing roast profiles! Keeping my fingers crossed that doing so will provide some useful information for reproducing a roast!