Iranian Pistachio Standards
Institute of Standards and Industrial Research of Iran (ISIRI) defines standards for the following Iranian pistachio products:
• In-Shell Pistachio Nuts: ISIRI 15 4th revision
• Mechanically Opened Pistachio Nuts: ISIRI 4919 1st revision
• Closed Shell Pistachio Nuts: ISIRI 4921 1st revision
• Pistachio Kernels: ISIRI 218 4th revision
• Split Pistachio Kernels: ISIRI 3639 1st revision
• Green Peeled Pistachio Kernels: ISIRI 4631 1st revision
• Pistachio Oil: ISIRI 6655 no revision
• Pistachio Paste: ISIRI 5691 no revision
• Pistachio Powder: ISIRI 9636 no revision
The following table contains an abridged version of specifications for the five pistachio grades set out by ISIRI Standard 15 (4th Revision January 2009) for in-shell pistachio nuts (including raw dried and roasted pistachios):
| Specifications | Superior Grade | Excellent Grade | Grade 1 | Grade 2 | Grade 3 |
| Shell Defects (%) (allowable tolerances by weight) | |||||
| Closed shell and blanks | 1 | 2 | 3 | 4 | 5 |
| Blanks | 0.5 | 0.75 | 0.75 | 1 | 1 |
| Adhering hull | 0.5 | 0.75 | 1 | 1.25 | 1.5 |
| Stained shell | 1 | 1.5 | 4 | 5 | 6 |
| Deformity (incl. opened from bottom) | 1 | 2 | 3 | 5 | 6 |
| Slightly open in-shell | 5 | 10 | 18 | 25 | N/A |
| Total shell defects | 7 | 13 | 22 | 28 | N/A |
| Kernel Defects (%) (allowable tolerances by weight) | |||||
| Loose kernels | 1 | 2 | 2.5 | 3 | 3.5 |
| Pest damage | 3 | 4 | 5 | 5 | 6 |
| Obvious pest damage | 1 | 2 | 3 | 3 | 3 |
| Total kernel defects | 3 | 4 | 5 | 6 | 7 |
| Other Defects (%) (allowable tolerances by weight) | |||||
| Foreign material | 0.25 | 0.3 | 0.4 | 0.6 | 0.8 |
| Foreign material excluding shells | 0.2 | 0.2 | 0.25 | 0.25 | 0.3 |
| Non-uniformity of variety | 1 | 2 | 3 | 4 | 5 |
| Non-uniformity of size | 1.5 | 1.6 | 1.8 | 2 | 2.4 |
Maximum Allowable Moisture Content: For raw dried pistachios: maximum 5% free water content, and for roasted pistachios: maximum 3% free water content.
Some Definitions:
Foreign material: Glass, metal and live insects are considered completely prohibited foreign materials. Acceptable foreign materials are pistachio related debris such as hull, stems, shells and sand.
Variety: Iranian pistachios are categorized into two categories according to their shape: long pistachios, where the ratio of the length to the largest diameter is more than 1.52; and round pistachios, where the ratio of the length to the largest diameter is less than 1.52.
Non-uniformity of variety: The percentage of round pistachios in a sample of long pistachios or vice versa.
Non-uniformity of Size: Ratio of the total weight of the 10 largest nuts in a sample of 100 nuts to the weight of the smallest 10.
