I am in the market for a kettle upgrade and have my eye on the Blichmann Boilermaker for doing boils (not mashes). I am really waffling between the 10 gallon versus the 15 gallon model. Why? Well, 95% of the time, I do the standard 5 gallon finished batch. In my 3 years of brewing, I have only wanted to do a 10 gallon batches 2 times. That 15 gallon kettle would have been awfully convenient for that. However, most often, I am doing the standard batch size. From what I gather, the 15 gallon kettle would work fine, except I might get a little more evaporation rate, and the thermometer probably would barely, if not even be in the wort for the 5 gallon finished batches. But, I would like the ability to do 10 gallon batches when I need too.
Let's face it, these kettles are not inexpensive. Would I be better off getting the 10 gallon kettle and taking full advantage of the features (ie. the kettle is sized correctly for 95% of my batches) -- forget about the 10 gallon batches and just do 2 brew sessions when I want 10 gallons?... Or am I being short sighted for potential future growth and would be better off getting the 15 gallon and not fully utilizing the features of the kettle (ie. thermometer)?
What have some of you done out there? Have you sacrificed convenience, quality or introduced process problems by using a larger kettle than what is generally needed for a typical 5 gallon finished batch?
Would love to hear some of your experiences and thoughts on the matter. Thanks!