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Thinking Outside the Can

November 25, 2011

There are two things I have been trying to excise from my life as much as possible lately: plastics and canned food.

The aversion to plastics probably makes more sense on the face of it, since as a petroleum product it is made from an increasingly scarce, nonrenewable resource and will not biodegrade once discarded.  This does not mean that it doesn’t break down at all, mind you; plastic photodegrades, or breaks down under ultraviolet light into ever smaller and smaller pieces without reverting to its most basic components (carbon dioxide, water, and other molecules, a process known as mineralization)1.  It remains a polymer, but becomes too small to easily collect or even to see.  These tiny pieces end up trapped in the water column where ocean currents concentrate them, such as the centers of gyres, the great circular ocean currents that ring Earth’s oceans.  In some places, such as the Great Pacific Garbage Patch, the accumulated plastic debris covers an area estimated to be twice the size of Hawaii2 – although exact size estimates are difficult when much of the debris is less than 5mm in size and is suspended as a tiny particulate cloud underneath the surface.

So, avoiding plastics wherever possible makes sense, especially in an era where they’ve become so ubiquitous and disposable.  But why canned food, exactly?

BPA-free labelling

The canned food issue actually goes back to plastics again, or more specifically to a component frequently used in it: bisphenol A, or BPA for short.  You’ve probably heard of the abbreviated form of this compound, as more and more plastic products proclaim themselves to be “BPA-free” and therefore safe to hold food and liquids.  The BPA issue circles back to the avoidance of plastics, since I don’t only eschew plastic products due to their total inability to break down but because of their potential for chemical pollution – not just of the surrounding environment, but of ourselves as well.  BPA is ubiquitous in the American population, with the CDC reporting that 93% of Americans tested have measurable amounts of BPA in their bodies3.  This is not slow accumulation, either; BPA is rapidly metabolized by the human body and will break down in just a few hours4.  For us to contain so much of this polymer, we must be constantly reingesting it multiple times a day.

This is not as difficult as it sounds.  BPA is one of the most commonly produced chemicals in the world4.  Some 70% of it is used to make polycarbonate plastic, the type of clear plastic used to make everything from CDs and DVDs, water bottles, drinking glasses, baby bottles, and even the reusable water bottles commonly used to replace the disposable plastic ones (hence the stickers on so many now that announce their lack of BPA).  About 20% is used in epoxy resins, used as adhesives, in dental filling material, the protective coating around wires – and the lining of pretty much every tin can currently on the market4.  Bisphenol A acts as a hormone disruptor, a chemical mimic that simulates estrogen and can interact with our bodies’ own hormone receptors and ends up either sending the wrong signal, too much of the right signal, or the right signal at the wrong time.  Unlike more conventional pollutants, which have toxic effects that scale with exposure, hormone disruptors are extremely toxic at very low levels because our bodies do not make much hormone to begin with and thus are sensitive to very low doses, causing extreme reactions to even small doses of the compound.  As hormones can have different effects at different levels, how the body reacts to BPA depends on the amount of exposure, with vanishingly small doses signalling for one set of genes to activate, higher doses turning on a different set, and very high doses shutting the genes completely off due to over-toxicity4.  In short, with BPA there is no level of exposure that is ever safe or will not cause toxic side effects, and the side effects are legion: depending on the timing of exposure, the genital tract and breast tissue can develop malformed (fetal exposure); testosterone levels can fall (fetal and neonatal exposure); breast and prostate cells become more predisposed to cancer (fetal and infant exposure); brain structure and function become impaired (young adult exposure); and the release of a key hormone involved in insulin sensitivity and inflammation is inhibited, possibly making us more susceptible to type-2 diabetes and cardiovascular disease (adult exposure).  These changes can occur with exposure times as short as two to three days4.

Although we’ve known about the hormone-disrupting properties of this compound since the 1930s, it was only in the 60s and 70s that BPA production became widespread4.  Even the few cans labelled as BPA-free can contain traces of the chemical, albeit at lower concentrations than more conventional cans and despite the linings of these cans not being epoxy-based5.  This stuff is everywhere, and it is very easy to ingest dangerous levels of BPA in a single serving.  The BPA-free cans are a safer alternative on par with frozen food in plastic packages, at least, but still – it’s there.

So, screw the cans.  As an experiment this Thanksgiving, I decided to try making my usual dish, pumpkin pie, without the use of any canned ingredients.  I even eschewed the Crisco I normally use to make the crust in favor of organic butter, which doesn’t necessarily come wrapped in a BPA-laden package (Crisco may not either, but since manufacturers are not currently required to tell you what’s in their packaging, it seemed safer to go the route wrapped in paper).

Preparing pumpkins for bakingStep 1: Pumpkin Puree

The primary canned ingredient in a typical pumpkin pie is the pumpkin puree.  Truth be told, the canned stuff is probably as much squash puree as pumpkin, but the two are quite similar and it still tastes appropriately pumpkinish, so I didn’t mind it for that reason – just for the can.  I started with a few small pumpkins from our kitchen garden (this was not a good year for them) and one hefty five-pounder from the farmer’s market.

First off, slice off the top of the pumpkin and cut the whole thing in half so you can scoop out the seeds and strings with a heavy-duty spoon.  If you’ve made Jack-o’-Lanterns before, this step is probably old hat.  Afterwards spray a baking pan with nonstick spray and place the pumpkins on to bake at 350°F for anywhere between 45 minutes to an hour and half – in this picture I’ve cut a slice off the bottom and baked them hollow-side up, but afterwards my mother told me it would probably have worked better with them the other way up, and with a little water in the pan to allow steaming.  In hindsight I was treating them a bit too much like the squash halves I regularly bake with butter and sugar in the center (one of my favorite fall and winter vegetables) but either method will probably work as long as the pumpkins are baked long enough.  Since I put so many in the oven, mine baked about two hours.

Once the pumpkin is soft and pierces easily with a fork, scoop the flesh from the skin or peel the skin away with a knife (whichever is easier) and puree the roasted flesh.  At this point, depending on what tools you have at your disposal, you can either run the pumpkin through a food processor or a food mill.  I prefer the use of a food mill to remove most of the significant pumpkin strings that might have been left behind.

Food mills are useful for stringy, seedy, skin-laden fruits and vegetables.

Step 2: Piecrust

I used a butter-based recipe from The Art and Soul of Baking6, reproduced here.  The original recipe I normally use and inherited from my great-grandmother, a turn of the century recipe, actually uses lard.  However, using fat from conventionally-farmed pigs when most of the hormone-disrupting antibiotics they are given are lipophilic (that is, retained in body fat) did not sound like a safe alternative.

Unlike a Crisco- (or lard) based crust, a butter crust was more difficult to work with because it had to be kept colder.  Butter has a lower melting temperature and must be kept relatively cold to behave like shortening when building a crust.  Since I’m relatively unpracticed at rolling out crusts in general (I make pies perhaps twice a year), this made getting the right size a little difficult, which was helped somewhat by the use of a pie sheet that also made it easier to peel up the rolled-out dough.

Flaky Pie or Tart Dough

Makes 1 (9- or 10-inch) pie shell
  • 1 stick (4 oz) cold unsalted butter, cut into 1/2-inch pieces
  • 3-4 tablespoons cold water
  • 1 1/4 cups (6 1/4 oz) unbleached all-purpose flour
  • 1 1/2 teaspoons sugar (omit for a savory crust)
  • 1/4 teaspoon salt
Butter being cut for piecrust

The butter looks odd because Mark had been using it to grease a pan just before I got to it.

Place the butter pieces in a bowl or on a plate and freeze for at least 20 minutes.  Refrigerate the water in a small measuring cup until needed.

The "crushed crackers and peas" stage.

The "crushed crackers and peas" stage.

Place the flour, sugar (if using – I didn’t, even for the pumpkin pie) in the bowl of a food processor and process for 10 seconds to blend the ingredients.  Add the frozen butter pieces and pulse 6 to 10 times (in 1-second bursts) until the butter and flour mixture looks like crushed crackers and peas.

Immediately transfer the butter-flour mixture to the large bowl.  Sprinkle a tablespoon of the cold water over the mixture and “fluff” it in, then add another, and another, until 3 tablespoons have been added.  Continue to fluff and stir 10 or 12 times.  It will not be a cohesive dough at this point but a bowl of shaggy crumbs and clumps of dough.  Before bringing the dough together, test it for moisture content; take a handful of the mixture and squeeze firmly, then open your hand.  If the clump falls apart and looks dry, remove any large, moist clumps from the bowl and add more water, a teaspoon at a time and mixing it in immediately, testing again before adding more water.  The dough is done when it holds together.  If the butter feels soft and squishy, refrigerate before continuing.

(Note – all of the above can be done in a stand mixer with the paddle attachment set to low speed.  Add three-fourths of the liquid to the mixer bowl, test for moistness, then add the remainder as needed).

Turn the dough onto a work surface and knead gently 3 to 6 times.  If it won’t come together and looks very dry, return to the bowl to add more water as described above before trying again.  Flatten the dough to a 6- or 7-inch disk, wrap in plastic or parchment paper, and refrigerate for 30 minutes.  This allows time for the dough to rehydrate fully and for the butter to firm up again.

If the dough sits for more than 30 minutes, it may be very firm and hard and will crack if you try to roll it.  Let it sit on the counter for 10 to 15 minutes until it is malleable but still cold.  Dust your work surface generously with flour and set the disk on the flour.  Dust the top with flour.  Roll, turning the dough, until you’ve got a 14- or 15-inch circle about 1/4 inch thick.  If at any point the dough becomes warm and sticky, gently fold it into quarters, unfold it onto a baking sheet and refrigerate for 15 minutes or until the butter is firm again.

Rolling out the pie crust

Fold the dough circle into quarters, brushing off any excess flour as you fold.  Put the point of the folded dough in the center of the pie pan, tart pan, or baking sheet and unfold, lifting it slightly as necessary to ease it into the crevices of the pan.  Do not stretch or pull the dough, which can cause thin spots, holes, and/or shrinkage during baking.

Using a pair of kitchen scissors, trim the dough so it overhangs the edge of the pan by 1 inch.  Fold the overhanging dough under itself around the pan edge, then crimp or form a decorative border.

Step 3: Pumpkin Pie

Pumpkin pie ingredientsThe normal recipe for pumpkin pie filling that I usually use (that is, the Libby’s staple on the back of every can) normally uses canned condensed milk.  To avoid that, I used another recipe from The Art and Soul of Baking that replaces it with whipping cream and whole milk.  Although I couldn’t completely get away from plastics – the organic cream came in a plastic bottle, but at least it wasn’t polycarbonate – this method does not use canned ingredients, and if you can find the dairy ingredients in a glass bottle all the better.

As it turns out, part of the reason for using condensed milk is because it is already thickened.  This recipe requires you to make a true custard filling by gently heating cream, sugar, and eggs without scrambling them.  A candy or instant-read thermometer is probably necessary here to track the correct point at which to stop cooking the filling and add it to the pie shell.

Great Pumpkin Pie

Makes 1 (10-inch) regular pie or 1 (9-inch) deep dish pie
  • 1 prepared, unbaked pie shell (see above)
  • 3 large eggs
  • 1 1/2 teaspoon ground cinnamon
  • 3/4 teaspoon ground ginger
  • 1/4 teaspoon nutmeg (about 20 grates on a whole nutmeg)
  • 1/4 teaspoon ground cloves
  • 1/4 teaspoon ground allspice
  • 1/8 teaspoon salt
  • 1 1/2 cups (12 oz) heavy whipping cream
  • 1/2 cup (4 oz) firmly packed light brown sugar
  • 1/4 cup (1 3/4 oz) granulated sugar
  • 2 cups (16 oz) pumpkin puree

Preheat the oven to 375°F and position an oven rack in the bottom third.  Line the chilled pie shell with heavy-duty foil, pressing the foil smoothly and firmly into the crevices of the pan.  Fill the pan with pie weights, making sure they reach to the sides of the pan – the center does not need to be filled quite as full.  Bake the shell for 20 to 22 minutes, until the foil comes away from the dough easily (if it doesn’t, bake another 5 to 6 minutes and check again).  Remove the pan from the oven, lift out the foil and weights from the shell, and return the shell to the oven to continue baking for about 20 minutes, checking after 10 minutes to see if any cracks have formed; if they have, use some extra pie dough to seal the crack to patch it and bake for another 10 minutes.  The pie shell should be a nice golden brown all over when it is done.

Preparing the custardRemove the shell to cool slightly and turn the oven temperature down to 350°F.

While the pie crust is baking, make the filling.  Whisk the eggs to break them up, then add the cinnamon, ginger, nutmeg, cloves, allspice, and salt and whisk well to blend evenly.  Whisk in the cream, brown sugar, and granulated sugar and blend well.  Add the pumpkin puree and whisk until the custard mixture is thoroughly blended.  Cook over medium-low heat, stirring continuously with a spatula and scraping all over the bottom of the pan to prevent the eggs from scrambling for 7 to 9 minutes, or until the mixture feels lightly thickened and registers 150°F on a thermometer. Do not let the mixture scramble or you’ll have to start over.  Remove from heat.

If the pie crust has cooled completely, reheat it in the oven for 5 minutes.  Scrape the hot custard into the hot pie shell and bake for 30 to 40 minutes, until the custard is set.  Test by tapping the pie pan – the center of the pie should look firm and move as  one piece.  Transfer the pie to a rack and cool completely, about 2 hours, before serving.

Results

The finished pie was, quite literally, the best I’d ever had.  Although it does take significantly more time and work to make I’d argue that it’s worth it, especially since several steps can be broken out of the sequence and performed ahead of time to avoid having to do it all at once.  The pumpkin puree made here made a batch large enough for at least two and potentially three separate pies, with the excess frozen; the pie crusts can be made in large quantities if you have a stand mixer, and the dough can be refrigerated for two days or frozen for up to one month.  Even if I wasn’t worried about the health issues of BPA in cans, I’d definitely be doing this again!

 

The finished pumpkin pie, plus extra filling baked in a ramekin.

Addendum

Since I was making the pumpkin pie already, I also made a second pie recipe for lunch on Thanksgiving since we tend to eat Thanksgiving dinner around dinnertime, i.e. about 7pm or so.  This recipe (from the same book as the other two) used some of the leftover cream as well as one of the many butternut squashes we had brought in from the garden.

Homegrown butternut squash, being cubed

Homegrown butternut squash, being cubed. I hadn't realized until I cut this one open just how big a difference there is between homegrown and store-bought squash.

Roasted Butternut Squash-Onion Pie

  • 1 unbaked pie shell
Squash
  • 10 ounces butternut squash, peeled and cut into 1-inch cubes (about 1 1/2 cups)
  • 1 tablespoon olive oil
  • 1 1/2 teaspoons light brown sugar
  • 1/4 teaspoon salt
  • 1/8 teaspoon black pepper
Onion
  • 1 tablespoon olive oil
  • 1 tablespoon unsalted butter
  • 1 large (10 to 12 oz) onion, cut into 1/4-inch thick slices
  • Salt

Custard

  • 3/4 cup (6 oz) whole milk
  • 2 large eggs
  • 1/2 cup (4 oz) heavy whipping cream
  • 1 cup (3 oz) finely grated pecorino cheese, separated into two half-cups
  • 1 tablespoon snipped fresh chives
  • 1 1/2 teaspoons finely chopped fresh thyme
  • 1 1/2 teaspoons finely chopped fresh sage
  • 1 teaspoon finely grated lemon zest
  • 1/8 teaspoon salt
  • 8 grinds black pepper

Bake the shell in the oven as described for the pumpkin pie recipe (see above).  While the crust is baking, line a baking sheet with a silicone mat or lightly coat it with cooking spray.  Use a spatula to

Caramelized onions

Caramelized onions, for the pie.

toss the squash cubes in a bowl with the olive oil, brown sugar, salt, and pepper until it is evenly coated, then scrape onto the baking sheet and spread the cubes apart slightly.  Roast on the top oven rack for 20 to 25 minutes, until deep golden and tender when pierced with the tip of a sharp, thin knife.  Let cool on a rack and decrease oven temperature to 350°F.

While the squash and pie shell bake, heat the olive oil and butter in a sauté pan over medium heat until the butter melts.  Add the onion and cook, stirring occasionally, until deep golden, 20 to 25 minutes.  Season with salt and set aside to cool.

In a large bowl, whisk together the milk and eggs until well blended.  Whisk in the cream, 1/2 cup of the cheese, the chives, thyme, sage, lemon zest (I used lemon oil), salt, and pepper.  Spread the caramelized onion in the bottom of the cooled pie crust, then scrape the squash into the pie shell and spread into an even layer on top of the onion.  Slowly pour the custard over the squash in a circular pattern.  Sprinkle the remaining 1/2 cup of cheese over the top.

Bake for 40 to 45 minutes until the edge of the custard puffs and the center is set.  Transfer to a rack and let cool for about 30 minutes before serving.

One roasted butternut squash-onion pie, ready to eat!

Happy Thanksgiving!


References

1. National Oceanic and Atmospheric Administration.  2011.  “Plastic Marine Debris: What we know.”  Retrieved from NOAA Marine Debris Program Website: http://marinedebris.noaa.gov/info/plastic.html

2. Moore, C.  2003.  “Trashed – Across the Pacific Ocean, plastics, plastics everywhere.  In: Natural History 112(9): 46-51.

3. Calafat, Antonia, X. Yee, L.-Yang, J.A. Reidy and L. Needham, 2008.  “Exposure of the U.S. Population to Bisphenol A and 4-tertiary-octophenol 2003-2004.”  Environmental Health Perspectives 116(1): 39-44.

4. Smith, R. and B. Lowrie.  2009.  Slow Death by Rubber Duck: The Secret Danger of Everyday Things.  Berkeley, California: Counterpoint Press.

5. “Concern over canned foods: Our tests find a wide range of Bisphenol A in soups, juice, and more.”  Consumer Reports Magazine, December 2009, accessed online: http://www.consumerreports.org/cro/magazine-archive/december-2009/food/bpa/overview/bisphenol-a-ov.htm

6.  Mushet, C.  2008.  The Art and Soul of Baking.  Kansas City, Missouri: Andrews McMeel Publishing.

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