No one wants their beautiful summer berry pie to be described as pasty, gluey, or lumpy. You worked hard to make that pie, and it should show.
Choosing which starch to use in your pie filling and using it properly will result in a luscious, delicate gel-like filling that will provide structure and hold together your lovely summer berries -- and not turn them into something that resembles hospital food jello or elementary school paste.
Choosing a starch can be confusing, however. Should you use flour, cornstarch, or tapioca? Which starch is the right one to show off your perfectly-ripe berries without overpowering their juicy goodness? And, just what the heck is the difference anyway?
Grain starches include wheat flour, cornstarch, and rice flour. A grain starch needs to be cooked very well (boiled for a few minutes) and works very well in cream pies where a pastry cream is the base for the pie. Cornstarch and rice flour are more translucent than flour, so the color of your berries will shine through better.
Root starches include tapioca (both whole and in flour form), arrowroot, and potato flour. A root starch needs gentle cooking and will thicken the juices as they are released from fresh or frozen fruit. Root starch is also more translucent than wheat flour.
A word of caution, though: if you intend to make a lattice top pie, stay away from tapioca granules for your starch. As the tapioca granules absorb liquid, they swell, and the oven heat will make them hard and unpleasant in your pie.
So which starch should you use? First, think about your fruit. Is it very ripe? A pie with ripe berries will need less time in the oven to cook and become tender. For this pie, try a root starch.
Are you using the first-picked crop of apples that may be less tender and juicy than they would be in a month or two and so the pie will need to be baked longer? If that’s your situation, go with a grain starch for the longer baking time.
Finally, here is the best tip I can give you for your berry pie: enjoy the bounty of summer’s star fruit, and don’t despair if your pie didn’t thicken like you wanted. Use the leftover filling in the pan as topping for vanilla ice cream. Delish!