Cooking can be surprisingly forgiving

Network analysis confirms ingredient swaps are feasible

If your pumpkin pie recipe calls for cinnamon but you’ve used the last of it, nutmeg, ginger or cardamom will do. Out of olive oil? Try applesauce. A new in-depth analysis of recipes, reviews and suggestions from an online foodie site reveals that many recipes are more flexible than standard cookbooks suggest.

SPICE STAND-INS Various spices can be used as culinary stand-ins for cinnamon, an analysis of recipe flexibility reveals. The direction of the arrow indicates which ingredient is being substituted for another. C.-Y. TENG ET AL/ARXIV 2011

Researchers mined more than 40,000 recipes and nearly two million reviews from the website Allrecipes.com, investigating various aspects of cooking and ingredient preferences. “We wondered if the analysis would let us see how flexible recipes are,” says coauthor Lada Adamic of the University of Michigan in Ann Arbor.

Her team discovered that there’s a lot of wiggle room. The analysis, reported online November 16 at arXiv.org, identified several clusters of ingredients that can be swapped for one another.

For the uninitiated, using less sugar than called for, or substituting or skipping an ingredient altogether, could ruin a dish. But distilling the collective wisdom of recipe reviews revealed alternates that would allow even the culinarily challenged to improve a dish or tailor it to their tastes.

Adamic, Michigan’s Chun-Yuen Teng and Yu-Ru Lin of Harvard and Northeastern University in Boston generated a list of the top 1,000 ingredients, which accounted for 94.9 percent of the ingredients in the database. The team noted heating methods, such as broiling and simmering, and various food processing techniques, both mechanical (such as grinding) and chemical (such as marinating). Recipe ratings and regional preferences within the United States were also taken into account.

Then the team created a huge diagram of ingredients that are frequently substituted for one another, yielding a network of clustered communities of swappable ingredients. A sweet potato community, for example, includes yams, pumpkin, potatoes, parsnips and butternut squash. Milk, butter, chicken broth and sugar all have recipe doppelgangers. And in some instances, dropping ingredients all together won’t hurt a dish.

A second ingredient diagram connected complementary ingredients, pairings that are found together more often than expected by chance. This network split cleanly into two communities, one sweet and one savory. The only other community detected was a small satellite cluster comprising alcoholic drink ingredients.

Recipes that had healthier substitutions were typically rated more highly by users, the researchers found, suggesting that making such swaps easier for users to find — such as with a roll-over or pop-up on a website — would enhance user experience. Restaurants or meal planners might even learn a thing or two, says Lin, perhaps experimenting with healthier replacements on menus.

Other foodie preferences also emerged. Recipes that called for processing foods in some way, rather than just tossing ingredients together, were rated more favorably. This link could relate to a longstanding hypothesis regarding the development of bigger brains in the evolution of humans and our hominid relatives, the team speculates. Processing food mechanically and chemically makes extracting nutrients easier, reducing the cost of digestion. Such techniques may have allowed more nutritional resources to be allocated toward growing bigger brains (SN: 8/22/11).

Which cooking method is preferred, however, appears to depend on regional tastes. While baking is popular everywhere, marinating and grilling are favored in the West and Mountain regions, and in the West this often entails seafood. Frying is especially popular in the South and Northeast, a trend that prompted Teng to look more closely at the data. The recipes suggest that while the frying signature of the South emerges from the soul food tradition, Northeasterners use a lot of bacon (especially in chowdah) and have a lot of recipes for buffalo wings.

“This research gives us a lot of insight into how different people want to eat their food, whether they prefer quick or healthy,” says Vaidehi Venkatesan who, with Ali Minai at the University of Cincinnati, is investigating the relationships among various cuisines. “It is a really great paper.”

And the research project helped the scientists feel slightly more at ease in their own kitchens. “I’ve felt more comfortable leaving out nutmeg,” Adamic says.