I recently tried pasteurising eggs at 57C for 90 minutes, gently adding them directly to the water with a silicone spoon. When finished, I discovered three out of the six had cracked.
Ideally, I want to store them in their shells in their original box, is there any way of preventing them cracking during this process?
If I do remove the pasteurised eggs from their shells, how long can I keep them if I vacuum seal them and store them in the fridge?
Try placing them in the water bath when the water is at a similar temperature as your eggs, then heating them together.
I cooked several batches of sous vide eggs and they never cracked. Until one day they did, and I had a little egg soup going twirling around my circulator.
I usually put them in straight from the fridge, when the water is already warm and had it break only that once. As moscafj said, safer to heat them together with the water.
Still, another safety precaution I do now is to add the eggs in a plastic bag - at least if it breaks it doesn't ruin my circulator and the mess is contained. I add some water in the bag to better distribute the heat and prevents the eggs from bumping around, which helps avoiding breakage.
