I was recently baking a recipe that called for 1 cup mashed strawberries (from 1/2 pound fresh strawberries). I used a large balloon whisk to do the job! I did not want to use a food processor or a se it would have pureed them, instead.

HOW TO TIPS:
Step 1: Place the berries in a large, wide bowl. Using the end of a large balloon whisk, I began to mash the washed and hulled strawberries in a straight down motion.

Step 2: Mash some of the berries and then toss them around with a spoon.

Step 3: Continue mashing the berries until you get the consistency you need. Do not overdo it!