Moretum, the origin of pesto

“A single colour, not entirely green

Because the milky fragments this forbid,

Nor showing white as from the milk because

That colour's altered by so many herbs.”
- Moretum

Moretum is the proto pesto. Vergilius (70 BCE – 19 BCE) mentions a moretum recipe in the poem of the same name. His moretum does not contain any basil, but a mixture of parsley, cress, endive and colewort. However, all the other elements (salt, garlic, olive oil and hard cheese) are there, more than twenty centuries ago.

The proper ingredients for a modern pesto Genovese:

A bush of fresh basil leaves, at least 50 gram just the leaves.
2 to 4 tbsp Parmigiano Reggiano (minimal 24 months old)
2 to 4 tbsp Pecorino Sarde (Pecorino Romano is too salty)
2 tbsp pine nuts
1 tsp salt
2 gloves of garlic
200 ml. olive oil, Ligurian preferably.

First crush the salt, pine nuts and garlic in a mortar. You need a big mortar, an electric kitchen machine will do, but after reading Vergilius’ poem, how can you not use a proper mortar and pestle? I bought a heavy granite stone mortar and pestle from Thailand for 25 euro.

Seperate the basil leaves from the stems. Cut the basil leaves with a sharp knife, so you don’t end up with whole leaves in the mortar, do not crush the leaves at this point!

In the mortar rub the basil leaves together with the salt, nuts and garlic, add the very finely grated cheeses in a 1:1 ratio (or more Parmigiano Reggiano than Pecorino Sarde). Carefully mix in the olive oil while rubbing the mixture with the pestle. Do not mash.

Never cook pesto. When heated basil gets bitter.