As cooks, we have all spent time blanching vegetables in large pots of boiling salted water. We've had the technique drilled into our brains, chef after chef preaches using vast quantities of salted water in order to preserve the color and flavor of our green vegetables. Common wisdom says that not enough water can lead to to the browning of our pristine, verdant specimens.
This morning I asked myself why we have never tried to cook green vegetables sous vide? Now by sous vide I mean under vacuum. We have explored the process of cryo-blanching and I recently became disenchanted with the process. It works and we'll continue to work with it although it doesn't feel like the best way to achieve our desired results. With that in mind I was pondering different methods of cooking green vegetables. Why do we cook something full of flavor and nutrients in a huge amount of water where flavors disperse and nutrients disappear? Mind you this is just assumption based on tasting the water after blanching vegetables. The blanching liquid tastes of the vegetable. We then pour this water down the drain. A waste of flavorful stock that our friend Tony Maws has most likely found a use for. The reason we have never tried cooking green vegetables sous vide is because everything we have been taught says that the vegetables will turn brown if cooked that way. It's a precept that has been drilled into our brains in various kitchens to such an extent that we never thought to question the actual science behind it. Today we put the theory to the test.
The result? Beautifully cooked asparagus in a vacuum sealed bag. Imagine now infusing seasoning into the vegetables. We could start simply with a bit of brown butter and a few drops of truffle oil and spiral upwards from there. The vegetables would cook with the seasoning and continue to marinate in the bag until needed. Today asparagus, tomorrow peas or haricot vert or well, you get the idea...