Juice always raises a red flag for pastry chefs because it can make the tart crust soggy The amount will vary with the season and the fruit Since we are all about control, we use the slurry because it binds the juice and prevents it from ruining our tart or pie Otherwise, the tart won’t set properly and the juice may ooze through the dough or bubble upward as the tart bakes The egg wash is brushed on the tart shell and will prevent it from becoming soggy (nothing yuckier than a soggy tart shell!) and extend the shelf life by 1 day The proteins in the egg congeal when exposed to the heat of the oven and create a barrier that protects the shell from the liquids in the filling The streusel absorbs liquid as well, adding additional protection INGREDIENTS | WEIGHT | MEASURE (APPROXIMATE) OR OUNCE WEIGHT Sweet Dough, Pâte Sablée or Pâte Brisée | One 9inch crust (½ recipe, about 350 grams) | One 9inch crust (½ recipe, about 123/10 ounces) 1 egg, beaten with 1 tablespoon water, for egg wash | 65 grams | 23/10 ounces Frozen wild blueberries | 280 grams | 10 ounces or 2¼ cups Granulated sugar | 51.5 grams | ¼ cup Lemon juice, freshly squeezed | 6 grams | 1¼ teaspoons ... shell!) and extend the shelf life by 1 day The proteins in the egg congeal when exposed to the heat of the oven and create a barrier that protects the shell from the liquids in the filling The streusel absorbs liquid...through the dough or bubble upward as the tart bakes The egg wash is brushed on the tart shell and will prevent it from becoming soggy (nothing yuckier than a soggy tart shell!) and extend the shelf life by 1 day