I have one stir plate and I plan to use it to do starter for a 15 gallon batch, the problem is that i'm splitting the batch into 3 carboys that i will use as fermenters. what technique should i use, or where can i find more information in order for me to do this. I have to say that this is the first time I do a starter and first time I plan to brew 15 gallons, I've was considering using 3 white lab yeast tubes for the 3 different carboys, but i really want to know if their is a possibility to use a starter and divided into 3 equal parts.