Some like it hot

And there may be a sound scientific reason for that.

There is a fairly strong pattern observable in human spice use. Specifically, the closer to the equator you are, the more likely that the local cuisine routinely uses a lot of spices. Consider, for example, traditional Indian cuisine vs traditional British cuisine. One is basically known for using All The Spices, and the other has a reputation of being almost comically bland.

Now, various hypotheses have been put forward as to why that is. It is hard to be certain of causality, when you’re talking about human behavior, but one factor that I suspect may be at least part of the answer has to do with food borne pathogens.

Numerous studies have shown that many spices have at least some degree of antimicrobial activity, often acting against bacteria and fungi that cause food spoilage, and in many cases even against direct human pathogens. The effects aren’t as strong as, say, modern preservatives, or things like refrigeration, but before those things were an option, adding things like garlic and cloves to food may have been one of the better available ways to make sure your food didn’t go bad before you could eat it.

Now, of course, while warmer areas had more to worry about in terms of food spoilage, food spoils everywhere. So why weren’t people in preindustrial Europe loading up their food with spices, to keep everything from spoiling? I think the main reasons were the scope of the problem, and the availability of spices.

In cold climates, while food will spoil, it generally will not spoil to a problematic degree in a few hours. So people in those areas did not have to worry significantly about spoilage between when they cooked food and when they ate it, just spoilage between when they harvested it and when they cooked it. There were other, better options for preventing spoilage during long-term storage. Salting, drying, pickling, and so on would keep food safe to eat for months, or even years, so the boost from adding spices would not make much difference.

But in very warm places, food spoils much faster. Modern recommendations suggest that perishable food at “room temperature” (around 20^oC/70^oF) should be safe without refrigeration for about 2 hours, but if the temperature is above 32^oC/90^oF, that range is decreased to about an hour. Most areas relatively close to the equator routinely exceed that temperature during the summer, so particularly if the person eating is not the one cooking, people might need to preserve their food at least somewhat just to get it from the stove to the plate safely. And while things like salting and drying work well for long-term storage, they generally make food at least somewhat unpalatable for immediate consumption. Perishable food that is salted enough to keep it safe from microbes, for example, would be too salty to eat as an entire meal. But food with enough, say, cloves to have a noticeable antimicrobial effect is perfectly edible as long as you like cloves.

At least when you’re talking about preindustrial Europe, of course, the other reason they didn’t heavily spice their food was the matter of availability of spices. There are a few spices, like garlic, that grow just fine in temperate climates, but the vast majority of the world’s spices grow primarily in subtropical to tropical areas. So, before modern transportation systems, things like cinnamon, cloves, ginger, and nutmeg were transported at great expense from thousands to tens of thousands of miles away. The very wealthy–who could also afford better food preservation methods, like ice houses, keeping meat animals alive over the winter until they actually wanted the meat, and so on–could afford spices, but the average peasant farmer or whatever could not.