Home > Uncategorized > Rethinking hot dinners and cold drinks

Rethinking hot dinners and cold drinks

May 13, 2013

NOTE: Images in this archived article have been removed.

This is part 5 of our serialization of Chapter 4 (Energy) from the latest Resilience guide, "Rebuilding the Foodshed: How to Create Local, Sustainable & Secure Food Systems". In this excerpt we enter the kitchen.


Food Storage and Preparation

Image RemovedData sometimes hurts, especially when it hits home. Just when it seemed like we could blame the farmer, the processor, and the distributor for our food energy woes, lo and behold, our constant culinary vacillations between hot and cold have conspired to put the American kitchen in the crosshairs of our food energy hunt. But this should be no great surprise, since the kitchen is the heart of household thermodynamic transitions.
Our refrigerators, freezers, ranges, microwaves, and dishwashers make our lives more efficient, but they also expand our energy budgets and our household energy costs. Cooking, refrigeration, and dishwashing consume more than a quarter of our household energy use. Of that energy consumption, refrigeration is responsible for 64 percent of the total, while cooking and dishwashing account for the remaining 26 percent and 10 percent, respectively.16 Add in lighting, heat, convenient kitchen gadgets, and exhaust fans, and the kitchen becomes the primary hub of household energy use—and when we can’t stand the heat but don’t want to leave the kitchen, we power up the AC.
So what does the household kitchen have to do with energy and relocalizing food systems? Everything. We make key energy decisions in our kitchens through a variety of short-term and long-term choices. Our choices of foods, storage techniques, preparation methods, kitchen design, and appliances all feed into our household energy footprints. And then there is an even bigger decision at hand: whether to stay at home to eat or to go out and grab a meal.
But before we run out of the house for yet more material to digest on the energy front, it’s worth thinking for a moment about thermodynamics and our food system. Once food is harvested, the human concern is to ensure that the food is safe, palatable, and nutritious. That’s where some of our biggest food energy questions come into play. We start to manipulate food temperatures in order to properly store and prepare foods.
Think for a moment about how many times we might alter the temperatures of a simple food product such as sweet corn. After cutting it off the cob, we heat and blanch it, freeze it for an extended period, and then thaw and cook it at some point many months later. Those are significant energy transformations. The embedded energy of the packaging needs to be considered, too, regardless of whether it is disposable or reusable.
The sweet corn example demonstrates the beauty of harvesting and preparing items fresh from the garden and preparing them as simply as possible in the kitchen. If we do it well, we’ve captured both taste and optimal nutritional quality by eating seasonally. As it turns out, the epitome of energy efficiency—home preparation of fresh foods—is married to the pinnacle of nutritional quality! Not only that, but the effort didn’t involve driving anywhere. In fact, the entire effort might have even involved some physical activity and aesthetic enjoyment.
But these direct, fresh experiences with our food are becoming less and less common. Consider a mélange of statistics that start to provide a picture of how we relate to food—and, ultimately, energy. The time spent in preparing and cleaning for a meal at home in the United States declined from an average of 65 minutes per meal in 1965 to 31 minutes in 1995.17 Between 1977 and 2006, the percentage of calories eaten away from home by children increased from 23.4 percent to 33.9 percent.18 A typical American consumes about 2,200 pounds of food per year at an estimated rate of 3,747 kcal/day (the FDA recommends an average daily consumption of 2,000 to 2,500 kcal/day).19 One researcher estimates that we Americans consume about 33 percent of our total calories in junk food.20
As we put the pieces of this puzzle together, we start to move toward a simple but reasonable guiding principle: every step we take away from home, fresh, and seasonal in the harvesting and preparation of our food increases our personal caloric intake and magnifies the energy footprint of that food. That said, we cannot afford to just chill out in a moment of self-congratulation—the heat is still on in the home kitchen.


Image RemovedWe humans have exploited heat in the preparation of our food for millennia, and we got really good at it. But we never had the opportunity to make extensive and controlled use of cold until the past century. Whereas heat drove our culinary adventures for most of human history, refrigeration has, in many ways, surpassed heat in its importance to our contemporary food systems.

The “cold chain” that binds together so many elements of our food system is a marvelous thing. In addition to minimizing food loss and waste, it provides us with enhanced nutrition and food safety as well as delectable staples of the modern diet, like ice cream (a personal favorite, so the energy realities involved are painful for me to describe in full here). The cold chain has offered us convenience and bounty from around the globe. As a result, refrigeration is probably the single most important contributing factor to the gradual melting away of robust local food systems around the world.
The use of refrigeration certainly helped some local economies flourish—we need only think of Florida and citrus as an example (although we might consider whether that growth helped to create a diverse, equitable, and healthy food system).21 Many previously robust local food systems withered with the influx of distantly produced refrigerated goods, some exotic and some far too familiar. Perhaps the most inane example of how refrigeration has upset our local, regional, and even national economies is that of apple juice. Apples are the second most consumed fruit in the United States and our third most valuable fruit crop, but freezing technologies and economic policies have allowed China to capture over 60 percent of the U.S. frozen apple juice market.22
Of course, the United States has also followed similar trade strategies made possible only through the use of refrigeration technologies. As a counterexample to the apple juice dilemma, the United States has glutted the Chinese market with low-priced poultry products, leading to a series of cross-Pacific games of chicken in trade negotiations.23 The point is not to cast blame on particular countries for various trade practices but to make it clear that refrigeration can be used both to the benefit and to the detriment of local food systems and their associated economies.
Refrigeration creates massive national and international markets, consumer convenience, and a diverse diet. It even provides locavores with the opportunity to eat more local products year-round, and it clearly has the capacity to provide us with products of optimal nutritional value. We should also bear in mind that refrigeration is the vital link in supplying safe and nutritious food from rural areas to peri-urban and urban areas—places that are growing in population at a rapid rate.
Our increasing reliance on refrigeration for convenience has also had a series of unwanted effects. It takes only one cursory circuit of a supermarket to feel the increasing encroachment of refrigerated aisles. The battalion of refrigerated and frozen goods is marching ever inward from at least three walls in most grocery stores, and that sensation is backed by data of all sorts. In the process of equipping our homes with refrigerators, freezers, and microwaves to accommodate an increased number of refrigerated products, we have also disposed of appropriate technologies and cultural traditions that helped minimize the need for refrigeration. Not only have we significantly moderated the internal temperatures of our homes in the past several decades, we’ve also eliminated cold pantries and root cellars from the typical house design. The common “summer kitchen” in the South was one sensible feature that kept the main areas of the house cool, but it is no longer in the contemporary architect’s repertoire. Springhouses and icehouses were once ubiquitous in rural areas, but those concepts have also virtually disappeared. Even food preservation traditions that did not rely upon any type of refrigeration have waned with fading memories and flashing regulatory messages about food safety.24 Salting, drying, and various forms of fermentation got shelved in our rush to the refrigerated aisles.
Revisiting the traditional foodways of your region can provide interesting insights into a world with minimal refrigeration and an era of fewer processed foods. At the same time, it’s important to demand sensible and highly efficient refrigeration technologies. Rest assured that those worlds can come together. I’m reminded of it every time I go down into the basement on a sunny day and pull a tub of homemade ice cream out of our superefficient Sundanzer chest freezer that runs on the equivalent of an eighty-watt solar panel. High in fat, low in calories—with a capital C, that is.

16. Alex Wilson, “The Energy Smart Kitchen,” Fine Homebuilding, Fall/Winter 2007.
17. David M. Cutler, Edward L. Glaeser, and J. M. Shapiro. “Why Have Americans Become More Obese?” Journal of Economic Perspectives 17, no. 3 (2003): 103.
18. Jennifer Poti and Barry Popkin, “Trends in Energy Intake among US Children by Eating Location and Food Source, 1977–2006,” Journal of the Academy of Nutrition and Dietetics 111, no. 8 (2011): 1156–64. The researchers indicate in their conclusions that these figures are, in fact, quite conservative, and the numbers are likely higher.
19. Pimentel et al., “Reducing Energy Inputs in the U.S. Food System,” 459.
20. Ibid., 460.
21. The Food Research and Action Center website provides extensive data and publications documenting the disturbing hunger levels of residents living in agriculturally rich regions such as some counties in Florida. For more information, visit the center’s “Data and Publications” page at http://frac.org/reports-and-resources/.
22. For information on apples and other U.S. agricultural commodities, see the Agricultural Marketing Resource Center “Commodity Apple Profile” pulled together by Malinda Geisler of Iowa State University, at http://www.agmrc.org/commodities__products /fruits/apples/commodity_apple_profile.cfm.
23. “WTO and U.S. Chicken Exports: China Puts Its Case,” the Poultry Site, September 22, 2011, http://www.thepoultrysite.com/poultrynews/23599/wto-and-us-chicken-exports-china-puts-its-case.
24. For a superb overview of the impacts of our food system on energy consumption and climate change, see the Food Climate Research Network’s report Cooking Up a Storm, by Tara Garnett (September 2008), available at http://www.fcrn.org.uk/fcrn/publications/cooking-up-a-storm. Tara Garnett also coauthored, with Tim Jackson, one of the best available histories of refrigeration in our food system in her paper “Frost Bitten: An Exploration of Refrigeration Dependence in the U.K. Food Chain and Its Implications for Climate Policy,” presented to the 11th European Round Table on Sustainable Consumption and Production, Basel, Switzerland, June 2007, and available at http://www.fcrn.org.uk/fcrn/publications/frost-bitten.

Image Removed Image Removed Image Removed        

Fridge grab and Frozen food aisle image via shutterstock.