Too much water will require cooking longer to get the consistency you want. Not enough water and the acorn will burn. Then special cooking rocks were heated in a fire, rinsed off, and using special stirring sticks, the rocks were stirred in the basket to heat the acorn solution thoroughly. As each rock cooled down, it was removed, and another hot clean rock took its place in the cooking basket. The rock that had been removed was washed off and placed back in the fire to reheat and await its turn to become a cooking implement once again.
Some people like to add a little cinnamon.
The rocks are saved for the next time, since finding perfect rocks that won't explode when subjected to heat, or won't crumble into the food, or give a bad taste, etc., are not as easy to find as you might think. The baskets, tools, implements, rocks, etc. used to cook acorn are considered a family legacy and kept within a family to be passed down from generation to generation. What makes a good cooking basket is the subject of another dissertation and shall not be gone into at this time. Ask the next expert basket weaver you meet to explain to you how a cooking basket is made. I check on the leaching process periodically, so I can empty the soup kettle as it fills.