Onion fluid gel

Ok, so I remembered it wrong. And had to improvise. But it actually turned out quite good. There is a video on youtube called The Fat Duck - Masterclass (Part 1 of 2) that I had seen a while ago, and they mentioned an onion fluid gel. As we did our shopping for the Sunday dinner, I wanted to try that with the meat we bought. But I could not remember the details. I knew they cooked onions sous vide and then made a fluid gel out of that. So I bought two red onions. As I came home, I found the video and the spot where the chef says "and we cook these sous vide for 96 hours". And this was on the Saturday with no 96 hours to be had. So I sliced the onions thinly and sealed them with a bit of olive oil and some baking soda in a ziplock sous vide bag. Since I do not have a chamber vacuum machine but one that sucks the air out from the edge of the bag, I cannot use it when there is liquid in there. One solution to that is to freeze the liquid, but this time I chose the ziplock bag using water immersion to try to get as much air out as possible. This, of course, leaves a bit of air in there causing the bag to float, especially as the air is warmed by the heat, so it has to be weighted down. Bit of a nuisance, but it works.

Why the baking soda? Just a whim. Baking soda makes stuff more alkaline. That makes the Maillard reaction accelerate. This reaction is responsible for the dark colours on browned meats, but it also gives rise to a wealth of flavour compounds. Normally this does not start to happen until the food hits 100-120 degrees, but perhaps the added baking soda would help. I do not know, but I tried. Did it help? I still don't know.

I cooked the onions in the water bath at 85 degrees for as long as I could before dinner on Sunday. That turned out to be a out 24 hours. When taking the bag out, the contents was quite brown, and quite a bit of liquid had gathered. I should have taken a picture, but I forgot. Anyway, I strained the liquid and also pressed some of the soft onions through a sieve. This gave me 170 grams of dark fluid. I gave it a simmer and added some salt and pepper and 1 gram of Gellan. Than comes out at about 0.6%. This set into a quite firm gel. After running my immersion blender through it, it came out as a rather thick and very tasty fluid gel. it may be that 0.6% Gellan was a bit much, perhaps 0.4 would be better. The fluid gel turned out as a quite thick pure. I will be looking more into fluid gels at a later stage.

But it was good, and that is the most important thing.