Cardoon for Vegetable Rennet

In the comments of my last post (Chèvre) there was some discussion about vegetable rennet, so I wanted to show you my cardoon. Two years ago I planted some, because I was told they can be used to make a vegetable rennet for making cheese. They are perennials so last year they just grew and established themselves. This year they bloomed.

To make rennet the purple stamens are collected and dried.

As I’ve been collecting and drying the stamens, I’ve been doing some research. Apparently, cardoon rennet is used to make specific cheeses. The ones in Portugal are called cardo cheeses: Azeitão, Nisa, and Serra da Estrela to name some of the popular ones. But I’ve been having trouble finding actual recipes for them. I’ve found a couple of videos, but they are more tourist demonstrations rather than how-to classes.

For using cardoon rennet, I’m finding varying instructions. One source says to use about 5 tablespoons of dried, powered cardoon stamens to make the tea for a gallon of milk. Another source says 1 to 2.5 grams per litre of milk, and still another says 1 gm for 2 litres milk. Quite a difference, and I suppose it has to do with the specific cheese being made. No matter, if I want to use it routinely as rennet, it’s going to take way more cardoon plants than the half-dozen I’ve got. Hopefully, I’ll have enough for an experiment. As far as growing it for a steady supply for cheesemaking, forget it. I can’t see myself growing an acre of cardoon plants just for that.

All is not lost, however, because cardoon leaf stalks can be eaten as a vegetable too. Very popular in Italy, France, Spain, and Portugal. They tend to be bitter in flavor, so commonly the leaves are pulled together and tied in a bundle to blanch them before harvesting. I wasn’t thinking about using them that way earlier, and now the plants are probably too late in this season’s maturity. So that will be for next year.

Once I harvest and dry enough stamens, I’ll make a cardoon solution and give it a try. And I confess I’m curious. Has anyone traveled to Portugal and tried some of these intriguing cheeses? Or maybe a Portuguese blog visitor can give me more information?

Cardoon is from a long list of plants that will curdle milk for making cheese. I’ve been collecting other things to try for vegetable rennet too. More on those later.