Sous Vide Cod Pil Pil

We may have discovered something new: you can make Pil Pil with plain cod, not just dried bacalao.

Previously, we'd used sous vide to minimize the oil and effort required for Pil Pil, the magical hollandaise-like emulsion. Every Pil Pil we've seen (and eaten) uses dried salted bacalao, preserved cod. We speculated that the mysterious emulsifying agent was within the fish skin, and that we might be able to develop the emulsion with fresh cod. Finding cod with skin on proved difficult but we found skin-on cod steaks at our local Korean supermarket.   We cooked it as before, with oil and some garlic in a sous vide bag, dropping the temperature to 65C/150F from the 78C/172F we used earlier.

Cod Pil Pil with truffled sunchoke risotto

Sure enough, the sous vide bag had some of the white emulsifying liquid in it, and this time the fish was beautifully moist and flaking apart in large chunks.  As before, we separated the liquid from the oil, whipped it with a mesh strainer until it started thickening, and drizzled in some of the oil from the sous vide bag until we developed a sauce. We added a bit of lemon to thin and brighten it, and adjusted with salt, and served it with the cod.  Really quite excellent.

429 g     Cod steak, fresh, with skin, portioned
250 ml    Extra Virgin Olive Oil
  4 clove Garlic, slightly crushed
  1       Chili Arbol
  1 pinch Salt

It can help to chill the oil before trying to vacuum seal the bag, but since we don't really care about the "under vacuum" part of "sous vide" as we're essentially low-temperature poaching, you can just seal carefully.

Cod, oil, garlic, chili in sous vide bag

Add the ingredients to the bag, seal, and cook sous vide at 65C/150F for 30 minutes. 
Drain the oil and precious white liquid into a tall narrow container.
Let settle a bit and suck out the white liquid that settles to the bottom with a turkey baster.
Whip that in a low temperature skillet with a mesh skimmer until it starts to thicken a bit.
Drizzle in some of the oil until the emulsion builds, then add more until you have as much as you like. 
Adjust density with lemon juice and water, season with salt.  
Serve on Cod.

What we learned

Pre-cut the portions of cod since they're quite fragile after cooking.
Fresh skin-on cod works as well as preserved salted and dried bacalao.
Lowering the temperature to 65C does release the emulsifying elixir.
We can add lemon and salt without breaking the emulsion.

Next Time

Salt the cod flesh a bit before adding to the bag.
Reduce the oil to just enough required for our portion of emulsified sauce, so we have none left over, maybe 50ml (3 Tbs).
Try dropping the temperature even further, to 57C/135F so it doesn't quite fall apart; hopefully, we'll still get the white emulsifying liquid.

Suspicions

Perhaps it's not the cod, or the cod skin that's the emulsifier; we've had success with Mahi Mahi. Is it possible the emulsifier is in fact the garlic cloves in the sous vide bag? We know garlic is a weak emulsifier from our delicious egg-free Toum.  Try without garlic some time.