The key to preparing this dough is to begin with your butter and dough at the same temperature and then keep it cold through the rolling and folding process. If you are making this in a particularly hot kitchen you may need more than 30 minutes of chilling time between folds. If the butter starts to seep through or the dough gets too soft at any point during rolling, pop it back in the refrigerator for 20 minutes or so before proceeding.