A Quick Guide to Manual Sampling
With harvest in full swing, it’s a good time to brush up on sampling.
Why Sampling Matters
Collecting representative samples is a very important part of presenting grain to potential buyers accurately, ensuring proper quality assessments, for the best pricing, and delivery options. Errors in sampling can lead to discrepancies in quality and pricing, causing stress during delivery.
To help take the best possible samples, we've put together some key tips with the help of the Canadian Grain Commission.
The Basics of Manual Stream Sampling
Here’s how to ensure sampling is hitting the mark:
1. Sampling Equipment
Grab a grain scoop (should have a rigid handle and be capable of holding 50 to 200 grams), multiple 20L pails (both for taking and splitting down samples), multiple bags to collect 2kg samples to present to grain buyers, and a 4 L pail to save an extra sample. Splitting samples can make a mess, so we recommend having a large hopper or tarp to do that over.
Image Source: Canadian Grain Commission
2. Sampling Every Truck that is Unloaded into the Target Bin.
Sample every truck and make sure to access the entire stream of flowing grain when sampling. This ensures that every part of the load is sampled equally.
Image Source: Canadian Grain Commission
3. Collecting Raw Samples
Collect samples at consistent intervals throughout unloading—from the beginning to the end, ending up with at least ¾ of a 20L pail for each truck sample.
4. Combining Samples
Combining truck samples that were unloaded into the target bin makes a representative sample of the bin. To do this, split down each truck load pail using the following method.
(a) Pour each truck sample over two side-by-side pails to divide it in half and discard one side. Then, repeat splitting the sample and discarding one side until left with about 1/8 to 1/4 of a 20L pail. Add this to the bin sample, ensuring every truck sample was divided the same number of times to maintain a representative amount.
Image Source: Canadian Grain Commission
(b) Next, to bag samples to take to different buyers, take the full bin sample and break it down using the same method as above. As always save a 4L sample. It is important to break the bin sample down like this to maintain a representative average of the bin as there may be variations in quality throughout the sampling process.
5. Labelling All Bag Samples
Harvest means a lot of samples, so labelling those samples right after bagging keeps things organized. On the label, include farm name, bin description and tonnage information. Next, make sure to also label the 4L pail with a bin description and tonnage information. Other good information to include: harvest dates, field locations and info that may be useful in making future agronomic decisions.
For a more detailed dive into manual stream sampling and other methods, check out the comprehensive guide on Canadian Grain Commission’s website.