A rice purity test, used often by the rice industry to determine the quality and type of a specific batch of rice, is a simple procedure that can be performed in any location with equipment easily available. It involves subjecting the rice to three different procedures:

Becoming familiar with these tests will help you be your own inspector of lower grade rices and will help in making sound purchasing decisions when purchasing rice. The most important thing to remember is that knowing how to perform a rice purity test, can save you from wasting money on low grade rices.

The following rice purity tests are not intended to replace laboratory analysis. They simply add another tool for determining the quality of your raw materials and finished products. No matter what method of testing you choose, know that sampling procedures must be approved by the United States Food & Drug Administration or meet the requirements of AOAC International methods before using them as an official quality check for food production purposes.

Testing Rice Samples: Screening Test

First we need some clean dry 200 meshed screen sieves. If you don’t have the 200 mesh sieve, just use a bigger one since all we are checking for here is gross impurities that will show up on any of our screens.

Use the larger sieve (even if it’s only 150 mesh) to pour your clean rice sample onto. Shake the excess off and using the smaller sieve, transfer about ½ cup of sample into a plastic baggie or container with a cover. The less surface area exposed to air, the better so make sure there is no spill over in your storage container. Store this sample in a cool dry place while you work with other samples or testings so as not to get confused which material is being tested for what.


Let’s make a solution using some of the material from our rice harvest. Since the pH of this water will affect how we view the differences between materials, we’ll use distilled water which has a neutral 7.0 pH to wash out any surface alkaloids that may be present on the needle-like crystals present in our brown rice sample (the outer hulls and bran). To do this, fill an extraction jar with about ½ cup (120 ml) of distilled water. Add your balling sieve to this jar and place it in a cool dry location that is free from airborne dust until you are ready for your test. Let’s assume you have been able to acquire some Psilocybecubensis mushrooms without making it.