How do I tell what type of potato I have?

You can identify your potato type through visual inspection and physical characteristics, following established quality standards used by graders worldwide.

Visual Characteristics to Check:

Start with skin appearance and color. According to USDA variety classification systems, white-skinned varieties dominate chip processing (about 20% of US acreage), while red, yellow, blue, and purple varieties are typically fresh market potatoes. The skin color is your first major indicator of variety group.

Size and Shape Classification:

Use the size grading standards from USDA and EU regulations. Measure your potatoes: <45 mm indicates smalls/seed potatoes, 45-65 mm is standard table grade, 65-80 mm is large, and >80 mm suggests baking varieties like russets. EU standards require minimum 35 mm for ware potatoes and 28 mm for early/new potatoes.

Skin Texture and Maturity:

Check if the skin can be easily rubbed off — this indicates early/new potatoes that aren't fully mature, according to EU Commission regulations. Fully mature ware potatoes have firm, set skin that doesn't rub off easily.

Physical Quality Inspection:

Following FAO and CIP guidelines, ensure your potatoes are firm and turgid (not soft or shriveled), have intact skin without cuts or cracks, show no visible disease signs like black scurf or silver scurf patches, and have uniform eye depth consistent with specific varieties. The shape should also be uniform — round, oblong, or russet-shaped depending on variety.

Nutritional Variation Note:

Remember that even within the same variety, characteristics can vary significantly. Research by Decker & Ferruzzi (2013) shows potassium content can vary 9-fold between varieties and even the same variety grown in different locations can have different nutrient profiles.