Creme Brulee Troubles

Good evening,

  I am looking for a little guidance on mastering the creme brulee... I utilize Joanna Gaines recipe and sometimes I have great success where everything comes out perfect and other times where the whole batch is trash... I cant find any consistency... The most recurring issue is when I go to bake the creme brulees, by the time 25ish minutes have passed, the cream is rising in the dish and the final texture of the product is nothing like a cream.. I can't tell if I'm putting in the wrong temperature for the water bath (I use boiling water), if I'm over mixing the egg yolks, if I'm not letting the heavy cream cool enough or letting it cool too much, or if I'm using the wrong dish to cook the creme in (glass 9x13).. Any help would be greatly appreciated... Thanks!