Are frozen vegetables ultra-processed?

Plain frozen vegetables are group 1, the same group as the fresh version. Freezing removes heat and adds nothing at all.

Blanching before freezing, which most vegetables get, is a brief cook to stop enzymes degrading them. It is heat rather than an ingredient, so it does not move them either.

What moves them

• Vegetables in a sauce or with butter added: group 3 or group 4 depending on the sauce.
• Anything coated or breaded: group 4, from the batter.
• Frozen roast potatoes and seasoned wedges: group 4, like frozen chips.
• Frozen herbs, garlic and chopped onion with nothing added: group 1.

This category is worth stating plainly because it is one of the cheapest ways a shop can contain group 1 food, and the assumption that frozen means processed is one of the most common mistakes about the classification. Fresh is not the test and packaging is not the test; addition is.

Working this out from a receipt is harder than from a packet, because a till prints about twenty characters of product name and no ingredients list. That is the problem Bagged exists to solve, and how a receipt is structured explains why it is the hard part.