How to Take Grain Samples This Harvest

With harvest underway, there is a lot of grain moving from the field to the bin. It is also a good time to think about how you are collecting your grain samples. Whether you are checking grain quality, comparing results, or preparing samples for potential buyers, it all starts with the sample itself.  

Why Representative Sampling Matters 

Grain quality can vary throughout a truckload or bin. Taking a scoop from one spot may not capture that variation. A representative sample is built from smaller samples collected throughout the entire lot of grain. The Canadian Grain Commission recommends collecting samples at regular intervals from the beginning to the end of the grain transfer and from different points within the grain stream. (Canadian Grain Commission⁠) 

So, what does that look like during harvest? 

1. Start With the Right Equipment 

For manual stream sampling, use a grain scoop with a rigid handle and a collector that holds between 50 and 200 grams. The scoop should consistently collect the same amount of grain each time it is filled. (Canadian Grain Commission⁠) 

You’ll also want to have: 

• 20 L pails for collecting and reducing samples 

• Clean containers or bags for your final samples 

• Labels and a marker 

• A clean area for working with and dividing samples 

Using clean equipment will also help prevent grain from another field, crop, or bin from ending up in your sample. 

2. Sample Throughout the Entire Truck 

The best time to build a representative sample of a bin is while it is being filled. As each truck unloads, collect smaller scoop samples at consistent intervals from the beginning of unloading right through to the end. For a falling grain stream, insert the scoop with the cup facing down. Once it is in position, rotate it 180 degrees to collect the grain and then remove it from the stream. (Canadian Grain Commission⁠) 

Alternate where you collect each sample between the left, middle, and right of the grain stream. This helps capture grain from different parts of the load rather than repeatedly sampling the same area. (Canadian Grain Commission⁠). Continue collecting until the truck has finished unloading. The CGC recommends taking enough samples to fill a 20 L pail at least three quarters full. 

3. Sample Every Truck Going Into the Bin 

If several trucks are filling the same bin, repeat the process for each truck. When the trucks are roughly the same size, the CGC recommends taking the same number of samples from each one. Each truck’s smaller scoop samples are combined to create a composite sample representing that truckload. This is important because grain quality isn’t necessarily identical from one load to the next, even when it is coming from the same field. 

4. Build Your Bin Sample 

Once you have a composite sample from each truck, the next step is to reduce those samples and combine them to create a representative sample of the entire bin. 

The CGC outlines a manual method using pails: First, thoroughly mix your truck sample. Place two empty pails side by side and pour the sample evenly where the two pails meet so approximately half goes into each. Keep one half and return the other half to the truck or bin it came from. Repeat the process with the remaining sample until you have the amount you need. 

Follow the same process for each truck going into the bin. The reduced truck samples can then be combined and thoroughly mixed to create one composite sample representing the grain in the bin. 

5. Reduce Your Final Sample 

Chances are, you don’t need an entire pail of grain every time you want to have your grain assessed. Once you have your representative bin sample, you can use the same sample reduction process to divide it into smaller samples for different purposes. 

The important part is to divide the sample rather than simply scoop some grain off the top. Grain within a sample can vary, so proper reduction helps maintain the characteristics of the larger composite sample. (Canadian Grain Commission⁠) 

Place your final samples into clean, sealed containers. 

6. Label As You Go 

By the time several fields and bins have been harvested, one grain sample can start looking a lot like another. Label samples as soon as you collect them. 

Useful information can include: 

• Farm name 

• Bin number or description 

• Grain type 

• Approximate tonnage 

• Harvest date 

• Field or location 

• Any other notes you may want to reference later 

Good record keeping makes it easier to connect a sample and its quality results back to the grain it represents. 

A Better Sample Gives You Better Information 

Sample throughout unloading. Change where you’re collecting from within the grain stream. Sample each truck. And when you need a smaller sample, divide it rather than grabbing a scoop from the top. 

Those few steps can help make sure the sample you’re assessing is a better representation of the grain sitting in the bin. For more information on official sampling procedures and equipment, visit the Canadian Grain Commission’s guide on sampling grain.