One of the interesting things about this dish is that the proteins (in this case meat) involved are not cooked using heat but chemical processes involving acids.
Do not be scared of acids. I’m not talking about huge vats of toxic green liquids that dissolve everything that falls inside. And there are no mad scientists in lab coats involved. It’s all about the citrus fruits and their juices which contain citric acid.
So what does it mean, cooking with acid? Under “cooking” we usually mean raising the temperature of an ingredient either by boiling, steaming, frying, sautéing, baking, etc. When the temperature increases, proteins denature, i.e. they unfold and change shape. However, this is one way of obtaining the goal. The same happens when they are exposed to acids.
So, what is the difference between cooking with high temperature and cooking with acid?
First of all, there are some other processes besides protein denaturation, such as turning of collagen (connective tissue) into gelatine, connected with heat. You cannot make aspic with acid. Thus, only very tender meats (mainly fish and veal) with little or no collagen are suitable for cooking with acid. (Also, Maillard reactions between amino acids and sugars happen only at temperatures above 140°C, producing many flavoursome compounds.)
Secondly, heat kills or inactivates various bacteria, fungi and enzymes which might be resistant to acidic environments. Therefore, freshness of the meat and hygiene in its preparation are essential for cooking with acid.
And finally, heat penetrates into the meat relatively quickly, denaturing and coagulating proteins with ease, whereas acid reacts much slower and it takes a long time to penetrate deeper that the meat surface. Thus, it is necessary to cut the meat into small cubes or thin slices before cooking it with acid.
Some wide known dishes prepared by acidic cooking have been around for ages, such as pickled eggs, ceviche, kinilaw, carpaccio… to name a few.
That being said, here’s a recipe for kinilaw I tried in the Philippines, this time with a Mediterranean twist. I hope you’ll like it.
Ingredients (for 4 people):
- Tuna – 300g
- Orange – 1 piece
- Lemon – 2 pieces
- Mango – half a piece
- Onion – one medium piece
- Ginger – small piece
- Salicornia (pickled) – to taste
- Crithmum (pickled) – to taste
- Salt and pepper – to taste
- Olive oil – a splash
As I have pointed out above, choosing the right piece of fish for kinilaw is essential. Choose fish with firm flesh and smell it before you buy – fresh fish smells of the sea. If it doesn’t smell fresh, maybe it can still be used for steaks or grilling, but definitely not for kinilaw.
Prepare the fish by filleting it and removing the skin. If you bought a piece of tuna, trim all the fat bits and tough white connective tissue. You want to have as much red meat as possible. Dice it finely (c. 5mm sides) and put in a bowl.
Take the freshly squeezed orange and lemon juice and mix well with the fish. You can also use vinegar for acidity, but I would not advise it. Vinegar (acetic acid) is too pungent and easily becomes the dominant aroma, completely subduing the wonderful subtle taste of fresh fish. Also, if the juice is too acidic, dilute it with water. My preference is that the juice is on the verge of being too sour to drink.
If the acid is too strong, it’s easy to overcook the meat, which will become completely white (effect of proteins denaturing and losing transparency) and bland in taste. The goal here is to have the outer layer milky white, and the inner layer still pink. Think about preparing a rare or a medium rare steak. This is the effect you’re aiming at.
It should take 20-30 minutes to achieve this level – depending of the juice acidity. Do not be afraid to experiment with your favourite citruses and constantly check the meat. Once done, strain out the juices.
Dice half of the mango into similar size cubes and add to the fish. Originally, green mangos are used, but a ripe supermarket mango is an equivalent. If you have access to fresh mangos, choose the firm ones. Finely chop the young ginger and onion – shallots or white onions are ideal because they are sweet and not too strong (sulphur compounds from yellow onions can also “kill” the taste).
Pickled salicornia and crithmum will add subtle touches of bitterness and Mediterranean freshness. Since both grow on the rock next to the sea, they compliment perfectly most seafood.
Finally, add salt and pepper to taste and a splash of extra virgin olive oil which will combine all the ingredients.
Mix well and leave in a fridge to cool down before serving. Serve on a fresh whole grain toast.