Buckwheat: Determination of dockage

Chapter 13. Buckwheat (PDF, 790 KB)

Definition

Dockage is assessed and recorded to the nearest 0.1%.

Dockage is defined under the Canada Grain Act as “any material intermixed with a parcel of grain, other than kernels of grain of a standard of quality fixed by or under this Act for a grade of that grain, that must and can be separated from the parcel of grain before that grade can be assigned to the grain”. Dockage is removed by following the cleaning procedures described in this section of the guide.

The sample as it arrives is referred to as the uncleaned or dirty sample. Its weight is the gross weight of the sample. Dockage is assessed on the gross weight of the sample.

Dockage is assessed in two stages.

  1. Follow Normal cleaning procedures, using the Carter dockage tester.
  2. Follow procedures for Cleaning for grade improvement. This cleaning can be done at any time after the cleaning assessment has been completed.

Dockage not reported

Important: Dockage is not reported for

  • Buckwheat, Sample Canada (size) Account Fireburnt
  • Buckwheat, Sample Salvage
  • Buckwheat, Sample Condemned
  • Unofficial samples declared as processed

Assessing dockage in small buckwheat

Normal cleaning procedures

Important: Wear gloves and a mask to handle any samples that you suspect may contain hazardous substances.

Buckwheat is considered small when more than 20.0% of the kernels pass through the number 8 slotted sieve.

  1. Set up the Carter dockage tester as follows:
    Set up the Carter dockage tester
    Feed control #6
    Air control #6
    Riddle number 25
    Top sieve number 6 buckwheat
    Centre sieve number 5 buckwheat
    Bottom sieve number 5 buckwheat
    Sieve cleaner control Off
  2. Using a Boerner-type divider, divide the uncleaned sample to obtain a representative portion.
    • Official samples shall be at least 1 kg.
    • Unofficial samples shall be at least 1 kg.
  3. Turn on the Carter dockage tester.
  4. Pour the sample into the hopper.
  5. After the sample has passed through the machine, turn on the sieve cleaner control briefly to dislodge kernels.
  6. Turn off the Carter dockage tester.
  7. Snap the retainer rod of the aspiration pan lightly to loosen material gathered on the screen.
  8. Determine dockage, using the list under Composition of dockage.

Composition of dockage

  • Material other than whole kernels of buckwheat removed by the number 25 riddle
  • Material removed through the bottom number 5 buckwheat sieve
  • Material removed by aspiration other than whole sound kernels of buckwheat
  • Soft earth pellets handpicked from the clean sample
  • Material removed by cleaning for grade improvement

Commercially clean

Samples exiting primary elevators are defined as commercially clean when the net dockage does not exceed 2.5% of the sample weight

Any whole domestic buckwheat removed in dockage assessment is returned to the clean sample. Dockage is reduced by up to

  • 0.3% for fine attritional material which passes through the number 4.5 round-hole sieve
  • 0.5% for broken or hulled buckwheat removed by aspiration or passing through the number 5 buckwheat or the number 6 slotted sieve

Cleaning for grade improvement

If the grade of a delivery can be improved by additional cleaning, perform the cleaning and add the additional material to dockage. Cleaning for grade improvement can be done at any time after the cleaning assessment has been completed, including on export.

  1. After the cleaning assessment has been completed, examine the material to be removed and select your equipment according to the material you want to remove. See the table Cleaning for grade improvement—Small buckwheat for the list of equipment.
  2. Sieve the sample by hand using the number 6 buckwheat hand sieve.

    Important: When you use a hand sieve, move the sieve from left to right 30 times, using a sifting motion. One time is one complete motion from the centre, to one side, to the other side, and back to the centre. The total distance from left to right is 20 cm, or about 8 inches.

  3. Weigh the additional dockage and add it to the original dockage.
Cleaning for grade improvement—Small buckwheat
Material to be removed Equipment Effect on composition of dockage
Foreign material number 6 buckwheat hand sieve The material passing through the sieve is included in the dockage

Assessing dockage in large buckwheat

Normal cleaning procedures

Important: Wear gloves and a mask to handle any samples that you suspect may contain hazardous substances.

Buckwheat is considered large when 20.0% or less of the kernels pass through the number 8 slotted sieve.

  1. Set up the Carter dockage tester as follows:
    Set up the Carter dockage tester
    Feed control #7
    Air control #6
    Riddle None
    Top sieve number 15 round-hole
    Centre sieve number 6 slotted
    Bottom sieve Blank tray
    Sieve cleaner control On
  2. Using a Boerner-type divider, divide the uncleaned sample to obtain a representative portion.
    • Official samples shall be at least 1 kg.
    • Unofficial samples shall be at least 1 kg.
  3. Turn on the Carter dockage tester.
  4. Pour the sample into the hopper.
  5. Turn off the Carter dockage tester.
  6. Determine dockage, using the list under Composition of dockage.

Composition of dockage

  • Material other than whole kernels of buckwheat passing over the number 15 round-hole sieve
  • Material passing through the number 6 slotted sieve
  • Material removed by aspiration other than whole sound kernels of buckwheat
  • Soft earth pellets handpicked from the cleaned sample
  • Material removed by cleaning for grade improvement

Commercially clean

Samples exiting primary elevators are defined as commercially clean when the net dockage does not exceed 2.5% of the sample weight.

Any whole domestic buckwheat removed in dockage assessment is returned to the clean sample. Dockage in shipments is reduced by up to

  • 0.3% for fine attritional material which passes through the number 4.5 round-hole sieve
  • 0.5% for broken or hulled buckwheat removed by aspiration or passing through the number 5 buckwheat or the number 6 slotted sieve

Cleaning for grade improvement

If the grade of a delivery can be improved by additional cleaning, perform the cleaning and add the additional material to dockage. Cleaning for grade improvement can be done at any time after the cleaning assessment has been completed, including on export.

  1. After the cleaning assessment has been completed, examine the material to be removed and select your equipment according to the material you want to remove. See the table Cleaning for grade improvement—Large buckwheat for the list of equipment.
  2. Sieve the sample by hand using the number 8 slotted hand sieve.

    Important: When you use a hand sieve, move the sieve from left to right 30 times, using a sifting motion. One time is one complete motion from the centre, to one side, to the other side, and back to the centre. The total distance from left to right is 20 cm, or about 8 inches.

  3. Weigh the additional dockage and add it to the original dockage.
Cleaning for grade improvement—Large buckwheat
Material to be removed Equipment Effect on composition of dockage
Foreign material number 8 slotted hand sieve The material passing through the sieve is included in the dockage

Optional analysis

Where a shipper requests special cleaning of a carlot of grain at a terminal elevator, and the elevator manager agrees, dockage material will be analyzed for the presence of grain. The percentage and grade of any grain contained in the dockage will be reported.

Procedures

  1. Analyze the official sample.
  2. Record the following on inspection records:
    • The percentage by gross weight to the nearest 0.1% and the grade of buckwheat.
    • The percentage by gross weight to the nearest 0.1% and the grade of grain separable from dockage.
    • The percentage of dockage.

Example

  • 95.0% Buckwheat, number 1 Canada
  • 4.0% Domestic Mustard Seed, number 1 Canada Oriental
  • 1.0% dockage