I love a good french toast. When properly done, it's a thick slab of bread that's crisp around the edges and rich and custardy in the center.
The challenge is to get the custard to entirely saturate the piece of bread, which usually requires planning a day or two in advance. Stale crusty bread in particular takes a loooong time for the custard to penetrate every nook and cranny of the bread. Even after a 24 hour soak, I'm often left with dry spots near the crust.
The other day, I awoke to a raging craving for french toast. Luckily I had the remainder of some crusty whole wheat bread sitting in the kitchen, unfortunately it was cardboard dry and about as tough. I started thinking about how I was going to remedy this situation when it occurred to me that the chamber vacuum in my sous vide setup might be perfect for getting the job done quickly.
I've been experimenting with using my VacMaster chamber vacuum to quickly infuse fruit with alcohol. The way this works is by reducing the air pressure around the food, which draws out all the air pockets between cells in the fruit. When the pressure returns to normal inside the chamber, any liquid that's sitting around the fruit gets sucked into the spaces between the cells like an expanding sponge. This instantly impregnates the fruit with the booze of your choice. I figured if this works at a cellular level, why not try it with bread, which has much larger air pockets.
Ten minutes later I was sitting down to enjoy some of the best french toast I've ever made. Even the crust of the bread had absorbed the custard, and upon frying the french toast in butter, the edges crisped up due to the sugar in the custard caramelizing.
The only problem was that I put it in a bag, so when the bag got sealed and the pressure returned to normal, the inside of the bag remained under a vacuum. This left an indentation in the middle of each slice of bread. What I realized was that the bag is totally unnecessary, since the infusion happens as the pressure drops and then returns to normal. Next time, I'm going to just put the bread in a tray with the egg mixture in it and stick the whole thing in the chamber to infuse.