Potatoes
3. Maturity and Firmness

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3.1 Requirements

The maturity and firmness requirements for each grade are as follows:

A) Canada No. 1

  1. Not be shrivelled or flabby;
  2. Except in the case of new potatoes shipped before September 16th in the year in which they were grown, have skins that will not loosen readily during ordinary handling and have not more than 10% of the surface flesh exposed.

B) Canada No. 2

  1. Potatoes are reasonably firm;
  2. Have no skinning requirements.

3.2 Terminology Used

Firmness and readily loosened skin are the two factors quoted in the grade standards that may be associated with potato maturity. Readily loosened skin may be referred to as "feathered".

The degree of skinning on individual potatoes refers to the amount of skin missing or feathered. Usually the more immature the potatoes, the greater the degree of skinning. In order to properly describe the degree of maturity, the following terminology shall be used:

  1. "Practically no skinning" means that not more than one-tenth (10%) of the skin of the individual potato is missing or feathered.
  2. "Slightly skinned" means that not more than one-quarter (25%) of the skin of the individual potato is missing or feathered.
  3. "Moderately skinned" means that more than one-quarter but not more than one-half (25-50%) of the skin of the individual potato is missing or feathered.
  4. "Badly skinned" means that more than half (50%) of the skin of the individual potato is missing or feathered.
  5. "Firm" means that the potato is compact, solid, not shrivelled or flabby or pliable and unyielding to moderate pressure.
  6. "Reasonably firm" means that the potato is slightly wrinkled, slightly pliable and yields slightly to moderate pressure.
  7. "Flabby" means that the potato is soft, limp, pliable and yields to moderate pressure.

Since no skinning requirements exist for Canada No. 2 potatoes or new potatoes shipped before September 16 in the year in which they were grown, the inspector should use one of these terms that accurately describe the degree of skinning. Commencing September 16, the inspector should use the term "mature", which means "firm, practically no skinning" and indicates compliance with Canada No. 1 grade requirements. With respect to firmness, the term "reasonably firm" for Canada No. 2 is used to indicate compliance with the grade requirements.

The September 16 date should not be confused with the October and July dates that affect the size requirements for new potatoes.

In the majority of cases, it is expected that firmness and skinning would be sufficiently uniform that the use of more than one descriptive term for each would be unnecessary. However, where necessary, general terms may be used, e.g., "mature" or "badly skinned, firm", or "slightly to badly skinned, generally moderately skinned, firm".

When a lot of potatoes fails grade on account of lacking firmness or skinning requirements, report the exact percentage of specimens failing the specific requirement. For example, if the lot fails due to excess skinning, the percentage of specimens should be reported as: "average 22% badly skinned, the remainder moderately skinned". Similarly, if the lot fails on account of lacking firmness, (i.e., flabby) it should be reported as: "average 28% flabby, remainder firm to reasonably firm".

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