Coffee Bean Moisture Meters

The final consumer may be a little unaware of this more technical type of instrument, but coffee producers, pickers and roasters are certainly familiar with the use of humidifiers. These are the moisture meters for coffee. They are also used for cocoa and other types of beans and cereals, but we will naturally focus on those for coffee.

Coffee and cocoa bean moisture meters are portable, easy to use, accurate, and not too cheap. Prices for coffee moisture meters can range from £70-80 for the simplest, to the several hundred pounds that professional moisture meters cost.

Although they may look similar, and the novice user may be confused, coffee moisture meters have nothing to do with refractometers. Refractometers do not measure the humidity, but the density or concentration of the coffee in a liquid, and act on the coffee already brewed (the beverage), not on the bean. Make no mistake!

What a coffee moisture meter is used for

Coffee bean moisture meters are used after the harvest of the bean, during the drying process.

Green coffee beans, after being harvested from the plant, contain approximately 45% to 55% moisture. However, the ICO (International Coffee Organization) dictates that green coffee must have a maximum moisture content of 8% to 12% before it is roasted.

The drying process is used to achieve these rates, and moisture meters for coffee beans are used to monitor the necessary drying time. Otherwise, it would be impossible to guarantee an optimum moisture level, because moisture is not something that can be measured “by eye”.

There are many techniques and procedures for drying coffee beans, sometimes adapted to the specific characteristics of each bean or origin. But what never changes is the need to use a bean moisture meter to know when the coffee is just right.

The moisture content can have a crucial impact on how the coffee beans are roasted and how they taste afterwards, so the use of technical equipment and gadgets like this is more than justified if you want to achieve a good yield.

How moisture meters for coffee beans work

There are essentially two types of meters.

The more advanced ones, such as the Agratronix Coffee Tester, have a compartment where we put the beans or seeds whose humidity we want to measure. All you have to do is close the lid tightly and press the “test” button. After a few seconds, the display of the meter will show the degree of humidity of the bean, and sometimes some additional data such as the room temperature.

These are fairly simple instruments, which are normally battery operated. The difficulty lies not in how to use the coffee moisture meters, but in knowing how to read and interpret their data correctly and then make decisions regarding drying and subsequent roasting.

Here you can see one of this style:

CGOLDENWALL Coffee beans/ cocoa beans/ wheat/ corn/ grain moisture meter for 14 kinds grain
  • GM006 type grain moisture quick measuring instrument is a new generation of moisture instrument of our company's scientific and technological innovation. It has the advantages of time saving, labor...
  • This instrument has the following characteristics: 1. small size, light weight, easy to carry, high reliability, easy to use, fast measuring speed
    2. moisture measurement range is wide, up to...
  • 3.wide temperature range, suitable for use in the southern and northern high temperature and cold areas
    4.moisture temperature automatic compensation, measuring cylinder equipped with temperature...
  • Six, instrument configuration
    1, instrument one (including host, top cover)
    2, 9V battery section
    3, a manual
    4, a product qualification certificate
    5, a package of...
  • Seven, performance index
    1, battery specifications: 9V batteries (6F22)
    2. Measuring varieties: wheat, corn, japonica, indica, soybeans, rice, sorghum, rapeseed, millet, peanuts,...

As you can see, the container in which the coffee beans are inserted for measurement is usually cylindrical and black.

On the other hand, we have moisture meters with an external connection. In these we see a pair of pincers, probes or antennas, which are responsible for measuring the humidity. We must insert them into the food or grain we wish to test.

Portable Damp Digital Meter 2 Pin Grain Moisture Meter with Long Proble for Rice Coffee Wheat...
  • Probe to measure 8 food varieties
  • Operation keys, made of ABS plastic with both toughness and easy operation
  • Long battery life, using 3 AA batteries, long battery life (battery is not included)
  • LCD display: clear and bright LCD screen with LED display chip, can be clearly viewed at any angle
  • High precision and fast response: The measurement is accurate and fast, and the measured humidity is displayed for 1 second; the HOLD key holds the data and the reading is convenient.

These meters are also battery operated.

Note: It is usually advisable to do several tests, about three or four, and to take the average moisture out of all of them. With a single test, the result may have some margin of error.

The best coffee moisture meter: Wile Coffee

In the world of humidity meters, there are usually two devices that are the absolute reference in the sector: The Agratronix meter and the Wile Coffee. Both are similar and either will guarantee you the best performance and maximum precision. We are going to choose the Wile Coffee moisture meter for our review.

Wile COFFEE Humidmeter for Coffee and Cocoa Beans, Premium Precision Moisture Meter for Traders,...
  • The Wile COFFEE Moisture Analyzer for Coffee and Cocoa is a portable humidity meter that measures humidity in green coffee Arabian, Robusta and Pergamino varieties, in roasted coffee and cocoa. Use...
  • Portable with carrying case and 9V alkaline battery already included. Very comfortable and lightweight to wear on the shoulder or on the vehicle.
  • Measurement is virtually immediate. Results in about 20 seconds on its high clarity LCD display. Small sample size Approximately as a cup of coffee
  • Accuracy +/- 0.5% approximately depending on grain type. Measuring range from 1% to 36% depending on the species of the measured grain. Adjustment of each product separately by the same user up to +/-...
  • With auto off function and two temperature sensors to correct the result. It also allows you to measure almonds and carobs with board (request separately). Various models with different product lists.

This is a battery-operated moisture meter for coffee and cocoa beans (not suitable for other ingredients) which is a perfect size to take with you to your harvest and work in the field. It has several profiles for different types of beans (e.g. arabica, robusta, parchment coffee) and the information is displayed on a simple digital LCD screen.

It comes with a practical carrying case, and measurements are quite fast (in the order of 20-25 seconds maximum).

The Wile Coffee moisture meter’s measurement range is from 1% to 36% moisture, with an accuracy of half a degree (+- 0.5%). Its price is obviously not cheap, but we must not forget that it is a device aimed at professionals.