Cooking condensed milk in pressure cooker?

[El Comandante]

My Cuban wife wants to cook a can of sweetened condensed milk in the pressure cooker for an hour. She's quite certain that the can should be unopened. She says that her mother cooks this often, and even called her mother to verify that the can should be cooked unopened.

Does the pressure cooker prevent the can from exploding? I suppose that if the pressure in the pressure cooker increased proportionate to the pressure inside the can, it wouldn't explode. Until you released the pressure from the pressure cooker.

Should I let my wife go ahead and cook this?

 

[Mama]

I found this article that may be of help: How to make Dulce de leche

This is what it says about using a pressure cooker:

"Brazil doce de leite (Portuguese for dulce de leche) is often made using a pressure cooker because it's safe and fast.

1. Put a liter of water in the pressure cooker with a can of sweetened condensed milk. Don't punch any holes in the can, but remove the label.
2. Bring the cooker to boil and wait for between 40 and 50 minutes after it begins to steam. Shorter time = lighter/softer doce. Longer time = darker/firmer doce.
3. Turn off the heat and wait until it cools down completely. While the cooker is pressurized by the steam, its pressure will counter balance the pressure build up inside the can, and prevent it from exploding. Let everything cool down before opening the pressure cooker. If you attempt to open a hot, or even warm can, an extremely hot jet of doce may explode out and result in severe burns. Wait until it is cool; then it will be perfectly safe to open the can and enjoy this great dessert."