I started my first batch with the converted protein powder jug. After several washings, I still couldn't get rid of a slight left over oder from the powder. We'll see if it changes the taste. Filled to the brim, the jug is just shy of 2 gals. Used a marker pen to mark various volumes on the outside. That helped in topping off the wort to the desired volume. I scaled an English Brown Ale recipe to 1.5 gal to allow for krausen. The next day showed good bubbling through the air lock. Will check on the taste in about 4 weeks.