Celebrating National Strawberry Rhubarb Pie Day

Today, June 9th, is a notable day in history. Let's look back over the years. In 1822, Charles Graham received the very first patent for false teeth. In 1902, the very first Automat opened in Philadelphia, making today the actual birthday of modern fast food. Additionally, Donald Duck (the only classic Disney character I like) made his first appearance on this very date in 1934. But most importantly, today is National Strawberry Rhubarb Pie Day! In celebration, I present to you: Strawberry Rhubarb Pie!





Now, what exactly is rhubarb? From a strictly botanical standpoint, it is a vegetable. However, in the US it is legally a fruit, thanks to a decision by a NY court in 1947. In case you wonder why our legal system would bother getting involved in this botanical boondoggle, it was largely done for tax purposes -- tomatoes also went to court, in 1893, and were judged erroneously to be vegetables. Rhubarb has been used for medicinal purposes in Asia for millenia, which is counter-intuitive when you realize that rhubarb leaves contain oxalic acid and are in fact nephrotoxic (i.e. toxic to the kidneys). But rest easy, you'd have to consume about 5 kg of the leaves (which apparently taste horribly sour) to damage your kidneys. None of this matters, of course, because rhubarb stalks are the bits used in rhubarb-containing foods. Making good eats from rhubarb stalks dates back to 17th century England, coinciding with the time when sugar became more affordable and available to the general populace. And then, voila! Rhubarb-and-fruit jams, pies, crumbles, and sauces!

Rhubarb season in the Northeast US is pretty short, from April-May and fresh rhubarb is preferable when available. However, many grocery stores also carry frozen rhubarb, which will do nicely as well. I've read differing opinions on whether the rhubarb should be thawed first and patted dry of excess moisture, or whether it should just be dumped in the pie and cooking time extended. Not having tried this pie with frozen rhubarb, I'm not sure which is method is better for frozen rhubarb, but I have a feeling that either will work as long as you watch your pie to make sure the filling is bubbling and the crust edge isn't overly brown (use a shield or aluminum foil around the edge if necessary). If you choose to fully thaw rhubarb, however, definitely drain it or blot it before using. If you don't thaw first, I would toss the rhubarb (and strawberries) with the flour and cornstarch before doing anything else. To keep the bottom crust from getting soggy, these are 3 good options that should work, your preference: 1) bake the pie on the bottom rack; 2) pre-bake the bottom crust for about 10 minutes at 425F (with weights and an edge shield); 3) spread about 1/2 to 1 tbls of flour on the bottom of the bottom crust before adding the filling.

This pie is presented 2 ways: one version has egg beaten into it, which results in a slightly custardy and delicious pie; while the other leaves out the egg. I prefer the egg beaten in, but they are both delicious. I include both ways because I made the egg-less pie first, and then I tried the pie with egg in the filling. The remainder of the ingredients are the same (except for 1 additional tbls of cornstarch in the egg-less pie), and cooking times/temps are the same for both.

Here is the pie with the custardy filling, dotted with butter

Ingredients

• Enough dough for a 2-crust pie. Ready-made or your favorite recipe (mine is here, courtesy of Alton)
• 2 1/2 C sliced rhubarb 
• 2 1/2 C sliced strawberries
• 1 1/2 C sugar
• 2 eggs (optional)
• 2 tbls flour
• 1-2 tbls cornstarch (2 if you omit eggs)
• pinch of salt
• 1/2 tsp ground cinnamon
• 1 tsp vanilla
• ~3-4 tbls cubed butter
• 1 egg white + 1 tsp water, beaten
• Additional sugar for sprinking

Directions

1. Decide whether you want to pre-treat the bottom crust (see above)
2. Pre-heat the oven to 425F
3. If using egg, beat 2 eggs and the sugar until fluffy (I used a whisk). Combine in the flour, cornstarch, cinnamon and vanilla with the sugar mixture (or just the sugar if you don't want to use egg). Mix in the fruit and toss to coat. 
4. Pour the filling into the bottom crust, and dot on the butter. Brush pie edge with egg wash.
5. Cover with the top crust, crimping to seal. Brush egg was over the top crust and sprinkle with sugar.
6. Collar pie with foil or shield, and bake for 15 minutes at 425F
7. Without opening the door, lower the oven temp to 375F and bake for an additional 45 minutes or so, until the filling is bubbling and the crust is golden.
8. Let the filling cool before serving. It needs time to thicken up a bit. 
9. Slice and serve!

On left: true lattice pie without egg; on right: Lattice cut pie with egg

In addition to the 2 slightly different recipes, I also prepared the top crust differently. For the egg-less pie, I actually weaved a lattice crust, and for the other pie, I used one of those lattice crust cutters. The directions say to roll the dough over the cutter, but of course I tried to press it down into the dough like a cookie cutter and it didn't quite work right. I think if I use it as instructed, it'll be easier. I like weaving the lattice myself, but a fair amount of the filling leaked out. The lattice stencil was a bit of a pain, but seemed to hold the filling in better. Of course, that could also be due to differences in filling consistencies because of the egg.

That isn't crust in the center of the lattice holes, it is a little of the souffle-like filling from the egg

All in all, I highly recommend either version of this pie, especially in rhubarb season. I'm not sure just why strawberry and rhubarb complement each other so well, but yumminess is definitely the result.