Buckwheat - Chapter 13 | Official Grain Grading Guide

Determination of dockage

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

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 No. 8 slotted sieve.

1. Set up the Carter dockage tester as follows:

Feed control #6
Air control #6
Riddle No. 25
Top sieve No. 6 buckwheat
Centre sieve No. 5 buckwheat
Bottom sieve No. 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 No. 25 riddle
  • Material removed through the bottom No. 5 buckwheat sieve
  • Material removed by aspiration other than whole kernels of buckwheat
  • Soft earth pellets handpicked from the clean sample
  • Material removed by cleaning for grade improvement

Commercially clean

Primary samples 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 No. 4.5 round-hole sieve
  • 0.5% for broken or hulled buckwheat removed by aspiration or passing through the No. 5 buckwheat or the No. 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.

  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 for the list of equipment.
  2. Sieve the sample by hand using the No. 6 buckwheat hand sieve.
  3. Weigh the additional dockage and add it to the original dockage.
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 eight inches.

Cleaning for grade improvement - Small buckwheat
Material to be removed Equipment Effect on composition of dockage
Foreign material No. 6 buckwheat hand sieve The material passing through the sieve is included in the dockage

Assessing dockage in large buckwheat

Normal cleaning procedure

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 No. 8 slotted sieve.

1. Set up the Carter dockage tester as follows:

Feed control #7
Air control #6
Riddle None
Top sieve No. 15 round-hole
Centre sieve No. 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 No. 15 round-hole sieve
  • Material passing through the No. 6 slotted sieve
  • Material removed by aspiration other than whole kernels of buckwheat
  • Soft earth pellets handpicked from the cleaned sample
  • Material removed by cleaning for grade improvement

Commercially clean

Primary samples 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 No. 4.5 round-hole sieve
  • 0.5% for broken or hulled buckwheat removed by aspiration or passing through the No. 5 buckwheat or the No. 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.

  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 for the list of equipment.
  2. Sieve the sample by hand using the No. 8 slotted hand sieve.
  3. Weigh the additional dockage and add it to the original dockage.

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 eight inches.

Cleaning for grade improvement - Large buckwheat
Material to be removed Equipment Effect on composition of dockage
Foreign material No. 8 slotted hand sieve The material passing through the sieve is included in the dockage

Assessing dockage in processed large buckwheat

Processed buckwheat is buckwheat that

  • Has been cleaned at a seed cleaning plant before being delivered to terminal elevators
  • Contains the type of foreign material usually found after commercial cleaning, such as attritional material

Samples may contain foreign material such as Tartary buckwheat and barley.

Normal cleaning procedure

Important:

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

1. Set up the Carter dockage tester as follows:
Feed control #6
Air control #3
Riddle None
Top sieve No. 6 slotted
Centre sieve No. 4.5 round-hole
Bottom sieve Blank tray
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. Turn off the Carter dockage tester.

6. Return all whole domestic buckwheat removed by aspiration to the cleaned sample.

7. Determine dockage, using the list under Composition of dockage.

Composition of dockage

  • Material removed through the No. 4.5 round-hole sieve. Deduct up to 0.3% for fine attritional material. For example, if 0.95% of material is removed, record the amount as 0.65%.
  • Buckwheat hulls and other material removed by aspiration, and material remaining on top of the No. 4.5 round-hole sieve. Deduct up to 0.5% for broken or hulled buckwheat.
  • Foreign material such as weed seeds, broken grain and roughage handpicked from the cleaned sample

Cleaning for grade improvement

Grade improvement procedures do not apply to samples of processed domestic buckwheat.

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% Wheat, No. 1 CWRS

4.0% Domestic Mustard Seed, No. 1 CAN Oriental

1.0% dockage