Guide

Allergens in pesto

Classic basil pesto usually brings milk from Parmesan or pecorino. Pine nuts are not one of the named UK tree nuts. If the tub uses cashews or walnuts instead, those are tree nuts and must be emphasised.

Reviewed 23 September 2026 against official guidance.SourcesNot legal advice.

The usual pattern

Green pesto is basil, oil, hard cheese and a nut or seed. The cheese is the allergen people miss because the word milk never appears on the front. Red pesto often adds sundried tomatoes, which can bring sulphites.

What to check in pesto

What you see	What it means on a PPDS label
Parmesan, pecorino, Grana Padano	Milk
Pine nuts	Not a named tree nut in UK allergen law
Cashew or walnut pesto	Tree nuts — emphasise the nut name
Some supermarket pestos	Also soya or wheat — read the spec

How to write it on the label

PPDS food needs the name of the food and a full ingredients list, with the 14 allergens emphasised every time they appear. The Food Standards Agency’s PPDS guidance is the practical reference. A typical ingredients fragment looks like this — yours must follow the specification of the product you actually use.

Example fragment

Basil, sunflower oil, Parmesan cheese (milk), pine nuts, garlic, salt.

Where it shows up

Chicken pesto sandwiches, pasta pots, traybake toppings and focaccia.

Swapping pine nuts for cashews

A cheaper pesto that lists cashews is a different label. Pine-nut pesto and cashew pesto cannot share one ingredients list.

Vegan pesto often drops the cheese and uses cashews. That removes milk and adds a tree nut.

Specification first

Brands differ. Treat this page as the usual pattern, then match the label to the tub, bag or recipe in front of you.

Questions

Do I declare pine nuts as nuts?

No. UK allergen rules name almond, hazelnut, walnut, cashew, pecan, Brazil, pistachio and macadamia. Pine nuts are not on that list. Still list them as an ingredient.

Is the cheese in pesto milk?

Yes. Parmesan, pecorino and similar hard cheeses are milk and must be emphasised, even though the ingredients line may only say the cheese name.

Official sources

Everything on this page traces back to these. Where they and we disagree, they are right — tell us and we'll fix it.

Introduction to allergen labelling for PPDS foodFood Standards Agency / GOV.UK
Labelling guidance for prepacked for direct sale (PPDS) food productsFood Standards Agency / GOV.UK
Food allergen labelling and information requirements technical guidanceFood Standards Agency / GOV.UK