A good number starts with a good sample. Let me show you!
Moisture guide
How to check moisture in rice and munji
Moisture decides the price, the milling yield and how long grain keeps. Here is how to measure it right, with a meter, an oven or by hand.
Safe moisture levels
The target depends on what happens next: selling, milling or storing. Wetter grain heats up and gets mould; over-dried grain breaks.
Munji (paddy)
- 20–24%At harvest
- 14%Selling
- 13–14%MillingBest
- 12–13%Storage 6–12 monthsBest
- ≤ 12%Seed
- > 15%Danger: dry it first
Milled rice
- 12–13%Bagging, storage up to 6 monthsBest
- ≤ 12%Long storageBest
- ≤ 14%Most buyers accept
- > 15%Danger: dry or sell now
With a grain moisture meter
The quickest way: a reading in under a minute. Most mills and buyers use one, so it helps to check your grain the same way before you sell.
6 steps for a true reading
For paddy and milled rice
- Sample from many places
Take grain from the top, middle and bottom of several bags or the heap. One handful from the top is not enough.
- Mix it well
Mix all the grain together and take a clean sample, without dust, straw or stones.
- Right setting
Choose paddy (munji) or milled rice, and the variety if the meter has it. The wrong setting can be 2–3% off.
- Cool grain only
Let grain from the dryer or the sun cool to room temperature, and wait a few hours after drying so the inside and outside even out.
- 3 readings, then average
Fill the cup to the line, press the same way each time, and take 3 readings from fresh samples. Use the average.
- Write it down
Note the date, the lot and the reading. Check the meter against an oven test once a season.
The oven test (the exact way)
Labs use this to get the true number, and to check that moisture meters are right. You need an oven and a scale that weighs to 0.01 g.
Weigh, dry, weigh again
Moisture = the weight the sample loses
- Weigh the sample
Weigh about 10 g of ground grain in a dry metal dish. Write down the exact weight.
- Dry at 130 °C
Ground grain: 2 hours at 130 °C. Whole grains: about 24 hours at 130 °C.
- Cool, covered
Let the dish cool with a lid on (in a desiccator if you have one), so it does not take in moisture from the air.
- Weigh again and calculate
Moisture % = (weight before − weight after) ÷ weight before × 100. Use the calculator below.
Example: (10.00 g − 8.65 g) ÷ 10.00 g × 100 = 13.5%
Without a meter: quick checks
Farmers have used these for generations. They tell you roughly wet or dry, but not the exact number: use a meter before you sell.
Bite a grain (husk a paddy grain first). Dry grain is hard and cracks with a click. Damp grain is soft, bends and leaves a tooth mark.
Push your hand deep into the heap or a bag. Dry grain feels loose and runs through your fingers. Damp grain feels cool, heavy and sticks together.
Shake a handful in a closed hand or a jar. Dry grain rattles with a sharp, light sound. Damp grain sounds dull.
Moisture calculators
Type your numbers: the result updates as you type.
Oven test result
Moisture % from the sample weight before and after drying.
Weight after drying
How much a lot will weigh once it is dried to a new moisture.
Common mistakes
Six things that make a moisture reading wrong, and how to avoid them.
Testing only the top of the heap, which is usually the driest part.
Testing hot grain straight from the dryer or the sun: the reading is wrong.
Using the rice setting for paddy, or paddy for rice.
Testing right after drying: the inside of the grain is still wetter than the outside.
Trusting a single reading instead of the average of three.
A meter never checked against an oven test.
Questions about moisture
What moisture should munji (paddy) have?
About 20–24% at harvest. Dry it to 14% to sell, 13–14% for milling, 12–13% to store for 6–12 months, and 12% or less for seed.
What moisture should milled rice have?
12–13% for bagging and storage up to 6 months, 12% or less for long storage. Most buyers accept up to 14%.
How do I check moisture without a meter?
Bite a grain: dry grain is hard and cracks with a click, damp grain is soft and leaves a tooth mark. For an exact number, weigh a sample, dry it in an oven at 130 °C and weigh it again.
Why does my moisture meter give a different reading each time?
Readings change with the sample, the grain temperature and the meter setting. Mix grain from several places, let hot grain cool, use the right setting for paddy or rice, and take the average of 3 readings.
How much weight does munji lose when it is dried?
About 7% of its weight when dried from 20% to 14% moisture: 1,000 kg becomes about 930 kg. Use the calculator on this page for your own numbers.
Dry enough? Check the quality too
Our free photo check measures every grain and shows the broken %, then you can send us your offer.