I must start out with a disclaimer. I am biased on this topic. I desperately want the answer to be yes, cooking can save the planet.
Among the things I have made from scratch are ricotta cheese, sour cream, brioche (photo, above) and tortillas — easy; as well as potato chips, croissants, tamales and candied ginger — not so easy, but mostly worth the effort.
A friend used to tell me that saying natural child birth is like saying natural surgery; if the drugs exist, just use them. And there are days when I think the same about convenience foods; there is a reason that candied ginger comes in nice little plastic packages from who knows where because really, who has the time to boil and rinse and boil and rinse and boil and rinse and then cook for an hour to make what is ostensibly a garnish.
So, when I called Helene York, the director of strategic initiatives at Bon Appétit Management Company and the architect behind the company's Low Carbon Diet program to reduce the greenhouse gas emissions from food service operations, I was really hoping she would tell me that packaged foods account for a large enough portion of the carbon emissions in the food system to make all that kneading and stirring and chopping worthwhile. After all, this is the company that set a goal of reducing meat on the menus in their 400 corporate and university cafes by 25 percent over two years and actually reached 33 percent.
The first thing York explained is that roughly 20 percent of greenhouse gas emissions in the United States come from what we eat, and about 1/3 of emissions globally are connected to the food system.
"People shouldn't feel guilty about enjoying food, especially if they choose the amount of food they actually eat and really enjoy it," says York, explaining that waste within the food system, at the farm level, processing level and at the table is a major problem.
But, she says "we might want to consider a little less of certain foods and make them a treat ... there are choices we can make that minimize what we're responsible for in terms of emissions. Just like we might choose to drive less or turn off the appliances, we shouldn't ignore the role that food plays."
I can verify through personal experience that when you start making your own French fries or potato chips, they definitely become a treat rather than a daily, or even weekly, indulgence. Like Pollan explained in his article, though, once somebody else starts doing all the work, that changes. But what about the role of processing and packaging in the emissions profile of our diet?
York warned me that deriving a percentage of emissions from food made in industrial kitchens is complex due to a number of factors.
"On an overall U.S. basis, very little, maybe 5 to 10 percent of food emissions, come from processing and packaging," she explained.
"A number of studies suggest food produced in commercial kitchens is 15 percent more efficient than food made at home, but that takes a lot of variables into account. You can't make the blanket statement that if you buy a packaged frozen dinner versus making the same food at home, that you will do better."
Among those variables are how the ingredients were produced, where and how they were grown, how far they traveled, the batch size and efficiency of the equipment used.
"If you are one person, or even two or four, and make a baked potato for each person and the oven is on for an hour, that's going to take a lot more energy per potato then if you get a potato at a work cafeteria and 200 potatoes were baked in an oven.
"There's efficiency in equipment, efficiency in batch size, but then those efficiencies are reduced with packaging and long-term freezing."
Astrid Scholz, vice president of knowledge systems at EcoTrust, concurs that in general, the highest energy inputs happen at the points of production, transportation and consumption.
"But anything highly processed or that has a lot of ingredients — which generally indicates it's highly processed — for each ingredient there is an environmental impact, plus energy and water to get to the finished product," Scholz explains.
"A stark example is our soft drinks. It takes as much as 200 gallons of water to create a gallon of cola. It's because of all the water for the corn that goes into the corn syrup, the washing of bottles and the processing. You should just be drinking water."
Tom Starrs of the Bonneville Environmental Foundation has written on this topic for the Center for Ecoliteracy and says the numbers for processing and packaging are actually quite high.
"Overall, about 15 percent of U.S. energy goes to supplying Americans with food, split roughly equally between crop and livestock production and food processing and packaging," Starrs writes. "David Pimentel, a professor of ecology and agricultural science at Cornell University, has estimated that if all humanity ate the way Americans eat, we would exhaust all known fossil fuel reserves in just seven years."
Take breakfast cereal, for example. According to researchers at Cornell University, it takes 15,675 kilocalories per kilogram to produce a box of cereal. The actual calories of the content in that box? Generally just over 1,000. Or as Jenny De Montalk described it in the New Zealand Herald, "a bowl of cereal with milk has emitted as much greenhouse gas to get to your table as a 6 km drive in an SUV would produce."
Or take canned corn: The Cornell research found that "all the energy inputs for producing, processing, packaging, transporting, and home-preparing a one-kilogram can of corn total 6,560 kcal. Contrast that with the 825 kcal of food energy provided by the corn. This means about eight kilocalories of fossil energy are expended to supply one kilocalorie of sweet-corn food energy at the dinner table."
Now compare that to buying a few ears of corn, taking the 5 minutes to cut it off the cob and the additional 5 minutes to cook it. If that corn is locally and organically grown, the energy input is reduced exponentially.
Finally, take a look at the good old tree-hugging, Prius-driving, vegan standby — tofu. According to Bon Appétit Management Company's Low Carbon Diet calculator, eating tofu has an environmental impact that is almost 1,000 times higher than eating soybeans in the form of edamame. Plus, in general, the edamame has more protein per serving and does not contain multiple ingredients that are difficult to pronounce.
So choices about packaging and production can have a significant impact. Again from the researchers at Cornell:
According to these numbers, by making thanksgiving green bean and mushroom casserole from scratch, I saved 4,929 kilocalories of energy on just the cans alone for the fried onions, green beans and mushroom soup. Add the additional savings from using fresh, locally grown ingredients, and it may just be worth the time it takes to clean the beans, make the mushroom gravy, and slice and fry the onions.
Even for those not crazy enough to spend the bulk of their free time in the kitchen, I asked Helene York if there were certain foods that consumers should try to always make from scratch.
"Soup!" York said with more than a little enthusiasm.
"The greatest burden for most soups is the can, which is usually made from a heavy tin with very little recycled content. Soup is easy to make, delicious and generally healthier when made at home and is an awesome way to use leftovers."
She went on to explain more about the importance of using leftovers:
"One of the biggest factors in the global warming potential of food is waste; agricultural waste, industrial waste, waste because the produce is not cosmetically pleasing and waste by consumers. If you have leftovers and you don't want to eat them in the same form, they are an awesome fodder for soup."
I would add to that list ricotta cheese (15 minutes to make, photo at right); pancakes (there is no reason on the planet to ever buy packaged pancake mix); most grain dishes, which take little time to make using fresh ingredients; and breakfast (see statistics about cereal above).
York believes that despite the decline in cooking, and the focus on science, modernity and convenience in our food system since the 1950's, things are starting to change. Just in the last two years, she has seen great interest among college students in knowing where their food comes from and learning how to make it themselves.
York says that concerns about climate impacts of the modern food system will also influence what commercial food companies do.
"I think we will see a real change in 10 years in how much fossil fuel energy is used to make, transport, warehouse, display and store food. Whether that's enough is not a question I can answer," she said.
"There are too many inefficiencies and fossil fuel inputs, starting with the way food is grown in the ground. Waste is very costly and built into the price consumers pay. After energy, that's the number two area that companies will be looking at.
"But whether we will ever get to an underlying sustainability in agricultural products depends on whether consumers and the media keep pushing its importance, as well as ties to food safety, the prevalence of pesticides in our food supply and the large quantities of soy, corn and wheat underlying all these packaged foods." She paused for a moment, then added, "If we get to those things, we have a shot at remaking the food system."
In the meantime, I have eight months to go of remaking our household food system, one meal — made from scratch — at a time.
(Photos: Leslie Berliant)