Hi all.

One of the most critical aspect of roasting seems to be humidity. If you get to 1C (a.k.a. first crack) with the right humidity, magic will happen. I think that measuring humidity would open a new world of possibilities.

Since humidity can be measured but it is difficult to do so, my question is open to ideas, suggestions, and ingenuity. How can humidity be measured in an environment like a roaster? It could be measured at the exhaust, but I think the problem is that the humidity probe would get dirty and it could get out of calibration.

Some humidity meters examples:

http://www.globalindustrial.com/p/tools...e-closeout

http://www.globalindustrial.com/p/tools...ter-rs-232

Cheers

Something like this?

http://www.tequipment.net/GeneralMMG608...5QodNBW1BA

but it only does 8% +

Tough job - maybe give these guys a call.

http://www.macinstruments.com/mac125.htm

I think you have to look to manage moisture in the beans and humidity in the roasting environment. I've always had a problem understanding how a fluid bed roaster could be considered ideal. During the winters in my area the humidity can get down in the 20s and at other times of the year it can get quite high. It's pretty obvious that when roasting outside in the cold or heat that we must compensate. But rarely do I hear concerns around humidity. The same needs to be considered in roaster designs. Convection can really help manage the speed and batch size of a roast but a what point or situation does it become a negative when considering moisture management in the beans throughout the roasting process.
Measurement would have to be tied with the ability to be able to do something about it. One of the reasons I believe roaster design is so important. All that I'm convinced of is too much dry air flow is a negative as is too much trapped moisture in the roasting environment. And that humidity in my roasting environment being sucked in by air flow needs to be considered. Beyond that I'm still thinking also.

The problem with the probes you reference is that they cannot survive high roaster temp for long without the probe melting.

However, if I were to do an analysis with such a probe I would use only in the bean bed (probably right in the middle of the bed up/down/crossways as that is the area you would be concerned about. Possibly fashion some type of quick insertion and release method for the probe (difficult for sure in a glass cylinder ...) . To adjust the humidity level would be easy; you use a mister nozzle that are sold for water foggers and position it above the heat source directly in line with the air flow into the bean bed. Adjust the water volume as needed to maintain the humidity you desire.

Len