I highly recommend freezing your tofu ahead. The water in the tofu forms crystals and tunnels that remain behind when thawed. This gives the tofu a firmer and more meaty texture that is just so good! I now keep a package in the freezer at all times and when I use it, just replace with the new package. If you didn't freeze ahead, consider cooking for a slightly longer time to make sure your result is on the firmer side.