Continuing the Strawberry Saga: Pie in the Sky

Name anyone who doesn’t like summer, strawberries, rhubarb and pie (combined, or separate), and I would be surprised. In my opinion, these delicious summer treats provide endless opportunities for culinary creativity: pies, jams, ice creams and gelato, plain, cakes, cobblers, crisps, relishes, sorbets, margaritas, gin fizzies…the list goes on.

The smell of rhubarb, for some reason, reminds me of my grandma’s kitchen in the summer (along with dill pickles and chicken fat), and that subsequently brings back memories of running around with my cousins at my Aunt and Uncle’s dairy farm in southern Wisconsin on hot summer days (alleviated by epic super-soaker and water balloon battles…and maybe a Scoepp’s vanilla ice cream cone from our grandma if we were lucky and/or fed the chickens earlier in the day). So, what better way to celebrate summer than with a pie made from fresh summer strawberries and rhubarb?

From the get-go, I had three “little things” I wanted to try. I hadn’t made a pie in over 6 months, and had been putting these “little things” off, so had to make them a priority:

-Try out my new “pie bird”

-Experiment with a new starch: tapioca!

-Prepare my pastry with a portion of ice water replaced with vodka

I accomplished 2 of the above, and managed to produce a beautiful, delicious pie. The one that I did not succeed in was using the pie bird. What is a pie bird, you ask? Well, you ask more politely than I did (“what the hell is this thing for?” while at this fantastic Madison kitchenware store). Apparently, you stick this cute ceramic penguin-esque bird into a pie shell prior to filling and placing on any top crust and/or lattice. The bird vents out steam, thereby reducing the final water trapped in the crust after baking, which evidently increases your odds for a dry, flaky delicious bottom crust.

I just couldn’t do it. Either the bird was too cute, or the notion of intentionally baking in a foreign object into a pastry just didn’t seem right (I blame my days in Quality!). My crust, as any proper pie or pastry dough should be, was full of Wisconsin butter (i.e. fat…), was not rolled too thin, and the filling was fairly dry pre-bake (and contained a very reliable gelling agent-tapioca). These factors in my mind were enough to ensure an adequate moisture barrier for a dry, flaky bottom crust.

The tapioca starch worked beautifully, and I suspect that I’ll be experimenting with it for more fresh-fruit pies in the near future. The gel is clear, and the starches present in the tapioca gelatinize (get thick) at lower temperatures than those in flour and cornstarch. This is perhaps another safe-guard for soggy bottoms: the filling thickens (traps water!) at a lower temperature (earlier in the baking process!), reducing contact time between wet filling and the crust during bake time. In addition, tapioca starch is relatively freeze-thaw stable, so feel free to stick slices or a portion of goodies made with it in the freezer. Lastly, the gelling capabilities are not diminished by acid and heat.

Now, for the vodka: I remember reading a pie crust recipe a few years ago that called for vodka in place of a portion of ice water, and thinking “yes, this makes sense, I shall try it soon!”. Two years later, I can recommend trying it out, but is definitely not necessary for an amazingly flaky, tender and delicious pie crust (have you seen any old-school Grandma pie crust recipes that call for booze? I didn’t think so, so don’t feel compelled to run out and buy some Stoli just yet). Feel free to omit the vodka, and add ice water instead to the recipe (which is a great crust recipe for all types of pie).

 Let me sport my Food Functionality and Chemistry Hat on, and try to explain the theory behind using vodka in place of ice water:           

Since water + flour (mainly glutenin and gliadin proteins) + agitation (mixing) = gluten, it would seem to be advantageous to reduce the amount of water, flour or mixing in a given pie crust recipe. Traditional recipes and techniques aim at just that. The goals with making pie crust are twofold: one being to develop as little gluten as possible, and two being to keep fat particles (chunks!) just large enough to be evenly dispersed through whatever gluten is formed (hence using a fork, or other pastry-cutting device, and very cold liquids to prevent melting the fat into the pastry). During baking, these intact chunks of fat melt, produce steam and create flaky pockets between the gluten formed in the dough.

 We know that we do need some water to help develop some amount of gluten, and to also dissolve/disperse salt and sugars in a given recipe (which also impact gluten formation, but we won’t go there now). But what if we could find another liquid that would develop some gluten and also help disperse salt and sugar? Vodka (or any plain-tasting alcohol, it really just needs to contain some high-ish amount of alcohol, or ethanol) fits the bill: the water content helps play to role that water would normally, but the non-polar characteristics of vodka help inhibit gluten formation. Gliadin, one of the main proteins in gluten, is soluble in ethanol (60-80% solution of ethanol), however glutenin is not. In order to form gluten, both of these proteins must be mobile (soluble) in a solvent that is neutral (pH=7.0, like water!) to allow for proper spacial configurations that accommodate interactions between the two proteins during mixing to develop gluten. If we tie one of those proteins up, as ethanol does to glutenin, the interactions that form the viscoelastic (gooey? Elastic? Stretchy? Silly Putty?) matrix are minimized! This is where the fun and food science really begin with gluten formation-but we won’t go there now. And as an added bonus, the alcohol will evaporate since ethanol has a lower heat of vaporization than water. This could also help product a dry, flaky crust. Hot damn!

Enough blabbing (if you’ve made it this far, congrats), here’s the recipe. I suspect that using frozen quartered strawberries and sliced rhubarb would be equally as delicious if you do not have fresh on hand.

Fresh Strawberry Rhubarb Pie

Makes one 9” pie with a lattice or full top crust

1 recipe all-butter pie crust, recipe below
3 1/2 cups (about 1 1/2 pounds, untrimmed) rhubarb, in 1/2-inch thick slices
3 1/2 cups (about 1 pound) strawberries, hulled and sliced if big, halved if tiny
2 TB Honey
1/4 to 1/2 cup sugar or dried sucanant
Juice and zest of 1 lemon
1/4 cup tapioca starch or small pearls (see note below)
1/4 to 1/2  cup sugar or dried
1/2 teaspoon salt
1 large egg beaten to blend with 1 teaspoon water (for egg wash glaze)

To prepare the crust: Preheat your oven to 400 degrees F. With a floured rolling pin, roll out half the dough on a well-floured surface. Roll out to about 12 inches in diameter. Using your rolling pin, roll the dough onto the pin, and then un-roll into your pan. Or, fold in quarters, and place in your pie pan. Nestle the dough in the pan; trim the edges for an approx. 1.5” overhang.

Now, make your filling: Stir together rhubarb, strawberries, sugars, lemon, lemon zest, salt and tapioca* in a large bowl. Mound filling inside bottom pie crust.

Roll the other half of pie dough into an approximately 12 inch circle, and cut into strips that are ¾ inch wide. Place the strips on top of the filling, alternating strips in a under/over fashion to make a lattice top, being sure to leave approximately 1.5” over-hang of each strip over the pie edge. Or, you could just place the top crust on the pie for a double-crust pie. If you go this route, make sure to cut in vent holes/decorative slits on the top crust. Fold top and bottom crust over-hangs under, and flute as desired (thumb-trick I learned from my Mom when I was little making quiches: make a thumbs up with your right hand, rotate your hand counter-clockwise until your thumb is parallel with floor, then place your knuckle down with your thumb facing the center of the pie. Gently rotate away from you about ¼ of a turn. Repeat around the crust).

 



Transfer pie to a baking sheet and brush egg wash over dough. Bake for 20 minutes at 400F, then for 25-30 minutes at 350F. The pie should be golden, and juices should be bubbling and thick.  Cool, and serve. The pie will keep up to 1 week in the fridge-but really, it should be enjoyed and shared when fresh!

Note: if you cannot find tapioca starch, purchase tapioca pearls and grind in a spice grinder, coffee grinder or food processor; alternatively, you could use small tapioca pearls as they are if you do not mind the pearls remaining slightly intact (think bubble tea, but not as firm) in the finished pie.

Flaky All Butter Pie Crust
Makes two 9-inch pie crusts, or enough for one double-crust or lattice top 9-inch pie

2 1/2 cups (12 1/2 ounces) unbleached all-purpose flour
1 teaspoon  salt
2 tablespoons sugar or dried sucanant
12 tablespoons (1 1/2 sticks) cold unsalted butter, cut into cube-esque shapes
1/4 cup cold vodka
1/4 cup cold water

Measure the flour, salt and sugar into a sifter; sift into a large bowl. Add half the butter (6 tablespoons). Using a fork or pastry cutter, cut in butter until mixture looks like polenta or corn meal. Alternatively, you could mix in a food processor (pulse 2 or 3 times). Add in the remaining 6 tablespoons butter, only this time cut the mixture until there are pea-size pieces of butter (promise-this will be worth the flaky awesome-ness!).  Add the ice water and the vodka, and with a fork or your hands, work into a ball. In a food processor, pulse until the dough comes together-may take a few seconds. The dough will be slightly sticky. Scoop out the dough on a lightly floured surface,

Form the dough into a disk, and wrap in plastic wrap. Chill for at least 2 hours. Overnight is best, but not necessary. If needed, the disc can be frozen for a later use (or you can whip up extra batches to have on hand in the freezer-one never knows when pie frenzy will hit!).