Why is my TrueBrew not letting me choose a recipe that is over the 16oz size.

Please check to see if the pre ground setting is selected. The pre ground setting can only be used for recipes of 3, 8, 12 or 16 ounces. Larger size recipes require multiple grindings and brewing cycles. If the pre groud setting is chosen, you wont be able to brew anything larger than a 16oz drink.