Of the five senses, I think that smell is the least understood or appreciated. We humans rely so much on sight and sound to communicate and receive information about the world around us, that it is easy to forget that odors, too, have a story to tell.
I’m thinking specifically about my experience on the farm. Sure, you may be thinking that farms provide a virtual buffet of smells…and you’d be right! But the amount of information that those odors can convey is truly astounding.
To shed some light on this under-appreciated sense, consider first HOW it all works. Molecules in the air come into direct contact with our olfactory receptor neurons, located behind our sinuses. These neurons instantly send that information to our piriform cortex, located behind the olfactory bulb in our brains, where we work to identify the odor.
Oftentimes, we instantly know what an odor is. Other times, we may not be able to identify exactly what it is we’re smelling, but something in our DNA tells us if it bad, good, or otherwise.
Walking through our winter barn, I can smell the freshly opened bale of haylage. It is sweet and lightly fermented, not unlike a beer mixed with molasses. The goats love it and so do I! I can smell the dampness of the air and animal bedding if it has been warm and rainy, so I know to open doors and windows to let in fresh air. I’ll then spread kiln-dried white oak shavings, filling the barn with notes of toffee and spice. If by walking in amongst my sheep and goats I get a whiff of something almost rotten, I know to look for bad feet in need of a trim.
In our cheese plant, too, we’ve learned to trust our noses more so than our eyes. The gleaming stainless steel and white walls may look absolutely spotless, but a flicker of sour in the nostrils tell us something is not as clean as it may appear. If a customer asks whether a cheese is still “good”, I recommend they trust their nose. Even on an industrial scale, tankers of cream are checked for a “graham cracker smell” and rejected if it is detected.
Smell and taste are very closely linked. Our brains process these sensations simultaneously, which is why foods are bland when your nose is stuffed. A good cheese, a juicy burger, a bowl of chicken soup all send signals to our brains well before they even hit our tongues.
Animals rely on odors on a whole other level. Mother goats and sheep know their kids and lambs by smell, often sniffing their rear ends as babies suckle. If a doe or ewe gives birth to a stillborn baby, some farmers will “trick” that mother into accepting an orphan by skinning the stillborn baby and putting that pelt on the orphan like a strange-looking vest. (I’ve never done this, but I understand the results are worth the effort.) Babies, too, know their mother’s milk and will refuse a bottle of milk replacer, even if they are starving.
Males (bucks, rams, bulls, and stallions) know when a female is coming into heat by sniffing her urine. Watch them closely and you’ll observe the “flehmen response”, a curling of the upper lip, and outstretched neck and tipping up of the head while inhaling deeply. Perhaps you’ve even witnessed your cat getting “the look” when smelling evidence of another feline. These animals have something we do not—a Jacobson’s or vomeronasal organ that allows them to detect organic compounds like pheromones and other hormones. They get a lot of information from a simple, single whiff!
But we humans have a different superpower related to scent. The area of the brain that processes smell is close to the hippocampus and amygdala, areas of the brain associated with memory. The limbic system, which controls our emotions, is also highly affected by smell.
This is why when I smell root beer, I am transported back to a childhood camping trip when I first tried real homemade root beer. Why the smell of a milking parlor brings tears to the eyes of a retired dairy farmer. Why the scent of lemon Pledge whisks me back to when our girls were little and that very silly (and mildly alarming) time when I diligently polished the railing on the front staircase, not realizing the overspray was hitting the steps themselves. (Those steps were unusable and remarkably slippery for a long time!) And when I think of the first few months as a young married couple, I can almost smell the salt marshes and fried clam shacks on the North Shore of Boston where we first lived.
What smells take you to a different place and time? Who knows what the nose knows!