I am still friends with Sarah (thanks to reconnecting on Facebook), and I asked her if she remembered the recipe, and as it's an old family favorite, she was able to explain how she makes it. However, her amounts were estimations (as she does it by eye and feel) and by weight instead of volume, so I had to do some mathematical calculations and experimentation. I also did a bit of online research to see if there was a common wisdom about the proportion of ingredients, and it seems like it's half as much sugar and butter as flour. However, I tried that, and it wasn't sweet enough to my liking. I prefer to up the sugar to about 75% of the amount of flour. The other important tip from Sarah is that you need a very thick layer of the crumble, so that the fruit juices don't bubble up and submerge the topping. Keeping these things in mind, here is my take on a triple berry crumble, in the English style. I believe I am now ready for the deluge of ripe summer fruit!
Triple Berry Crumble
6 cups berries (I used Wyman's frozen raspberries, blackberries, and blueberries)
1/2 cup sugar
2 heaping tablespoons corn starch
juice and zest of a lemon
1 tablespoon frozen orange juice concentrate
1 teaspoon vanilla
2 1/4 cups sugar
Preheat the oven to 350F.