Covid took my sense of smell, gave most of it back, and kept some. For a while coffee smelled like something scraped off a road. What I learned trying to get it back.
Covid took my sense of smell and gave most of it back and kept some for itself, the way a flood hands a village back with a few houses quietly missing, and there is no instrument in this house that can tell me how much it kept, only a cup of coffee, which for a whole season smelled like something scraped off a road after rain.
The house has become brown cardboard towers with the children's names on them in marker, and we fly in July, far enough away that the boxes still feel like a game to the boys, the older of whom is five and asks whether the new house will have snow, while the younger is a year old and eats the packing tape. The things fit in a truck and a few suitcases and the years refuse to fold into anything at all, and coffee is one of the few habits coming with me whole, the grinder and the scale and the moka pot wrapped in a tea towel, and, if I am lucky, a nose to go with them.
One thing is staying behind, and it stings more than I expected, because the capsule machine I bought two springs ago, the one that reads a barcode and hums like a small drone, runs on the wrong voltage for India and goes to a neighbour in July with the last boxes of dark capsules, after carrying me through a newborn and a company closing and the year my nose was gone. I will miss its ninety seconds every morning and I am quietly glad to leave it, because it was a shortcut, and we are going home meaning to get it right the second time round, which in the kitchen means beans and a grinder and measured water and the time it takes, a promise that feels like outgrowing a coat, sad and a little taller in the same breath.
This note is what I learned trying to get my nose back, and it answers the question people ask me most shyly, why everyone else finds blueberry and jasmine in a cup where they find only coffee, and my gentle answer is that their tongue works perfectly and most of what they call taste has been smell all along.
Five tastes, and an older six
The tongue reports on five things, sweet and salty and sour and bitter and the savoury depth that a chemist in Tokyo named umami in 1908, the taste of a good broth or the crust of a roast, and that is its whole vocabulary, so telling an apple from a pear, or one coffee from another, is work the tongue hands up to the nose. You will read a confident percentage for how much of flavour is smell, and I could find no source for it, so I leave it out and keep the sourced argument, which is more striking anyway: anything in the cup beyond those five is something you are smelling.
The list I grew up half hearing is older and longer, because Charaka, the physician whose compendium sits at the root of Ayurveda, counted six rasas nearly two thousand years ago, sweet and sour and salty and pungent and bitter and astringent, and every Bengali child served a bitter shukto at the start of lunch and a sweet at the end has eaten that list course by course without anyone naming it. The sixth, kashaya, astringent, which modern science files as touch, is exactly the dry, puckered grip an over-extracted coffee leaves on the gums, like the skin of an unripe banana or tea left stewing on the stove, and it makes the older list the more useful one for anyone holding a cup.
The nose at the back
There are two ways to smell, and the one everyone knows is breathing in with the cup under your nose, while the other, which does nearly all the work, is breathing out with the liquid in your mouth, so that the aroma climbs the back of the throat into the nose from behind, the way the smell of a kitchen comes up the stairs and finds you still in bed, and almost everything you experience as the taste of coffee arrives by that rear staircase.
This is why professional tasters slurp, with a noise like the last inch of a milkshake through a straw, because pulling in air with the liquid sprays it across the mouth and throws the aroma up that back passage, and it looks absurd and works, and the children copy me at home, and the older one now slurps his milk at dinner with the gravity of a man judging a competition.
Hundreds of volatile compounds have been found in roasted coffee. Only a few dozen are present in amounts a nose can pick up, and a handful of those do most of the work.
What is in there
Of the hundreds of volatile compounds chemists have found in roasted coffee, only a few dozen reach a level a nose can notice and a handful do most of the work, and the most important, the molecule that makes coffee smell roasted where it might have smelled merely brown, is a small sulphur compound with a long name that I will shorten to coffee's signature, the smell that leaps out of a bag of dark roast when you tear it open and that a light roast, to my nose, never quite manages, and I mention it because of what happened next.
The molecule that broke first
Two years ago chemists studying distorted smell after the virus, the condition in which familiar things smell rotten, chose coffee as their test substance, one of the commonest triggers and rich in molecules, and passed its aroma through an instrument that separates the compounds one by one while people with and without the condition sniffed each as it left a small port, like sniffing at the keyhole of a locked room.
The single worst offender among the triggers, the one most affected people called disgusting, was coffee's signature, which people with a normal nose described as roasty and smoky and like popcorn, while people with the condition had no words for it and reached for dirty and repulsive. The researchers suggest that these molecules have extremely low thresholds, so a regenerating nose may pick them up first, before the rest of the picture returns, like the first blurred pixels of a photograph loading on a slow connection, which in plain words means that the thing that makes coffee smell like coffee is the thing that breaks first.
That sentence explains the season I could not drink coffee, and why my beloved dark roasts, heavier in that molecule than anything on the shelf, were the worst of all, and it was strangely the first thing that made me feel better, because it put the road in the cup and took it out of my head.
You can learn to taste coffee
Smell training, and the hole in it
There is a treatment of a kind, from fifteen years ago, when doctors asked people who had lost their smell to sniff four scents twice a day for twelve weeks, rose and eucalyptus and lemon and clove, and about a quarter of those who trained improved meaningfully, against a much smaller share of those who did not train and improved on their own.
From the 2009 Laryngoscope study that started smell training as a treatment. A real effect, and a modest one.
It is a real effect and a modest one, and the charities for smell loss now recommend longer sessions over more months, so the protocol has learned the patience it asks of its patients.
When I looked into where the four scents came from I found something I have not seen written anywhere else: they are drawn from an old classification of smells into six families, flowery and fruity and spicy and resinous and burned and foul (six again, as if the senses like to be counted in sixes), and the kit keeps the flower and the fruit and the spice and the resin and drops foul, for obvious reasons, and burned as well, so that nobody's training kit contains the smell of a roast.
So the one classical family the standard protocol leaves out is the family coffee lives in, and since the charities say plainly that you may train with whatever makes you happy, I trained with coffee, twice a day for twenty seconds, a bag of dark beans held under my nose like a prayer, for a whole winter, and whether it helped I cannot say, and what I can say is that one morning in December the bag smelled like a bag of coffee again, warm and sweet and a little like burnt sugar, and I sat down on the kitchen floor. Is there research on training with coffee itself? I could not find any, and a whole profession built on the nose has mostly kept quiet about losing it, as one trade magazine admitted last year.
The library I was trying to recover
What frightened me in the lost season was the library behind the coffee, because a nose is a card catalogue of places and most of mine is filed under Calcutta: the book stalls of College Street, where paper gone yellow in the humidity smells of vanilla and dust, and the grease on the tram lines at Esplanade, black and faintly sweet in the afternoon heat while the bells clang like a bicycle's older brother, and the Hooghly at the Howrah end of the bridge, mud and diesel and marigolds browning on the ghat, and the phuchka seller's tamarind water, sour and green with coriander, and, drifting out of the Coffee House door, the infusion, dark and a little burnt, over a room where almost nobody was drinking it. I had carried that catalogue across an ocean without opening it, and when the nose went the catalogue went too, and on the December morning the beans came back the Coffee House came back first, because it sits on the same shelf as coffee's signature, and I stood in a Colorado kitchen and smelled College Street in the rain.
How to build a palate on purpose
This works whether or not you have lost anything, and although it is written as a method, what it gives me each morning is twenty minutes alone with my own attention, two cups cooling on the counter like a pair of small brown mirrors, and the moment cuppers live for comes at four minutes, when the spoon breaks the crust and the smell rises like steam off a pavement after a summer storm.
Cup at home
No equipment beyond several wide cups and a spoon.
An equal dose in every cup: about a gram of coarse-ground coffee for every seventeen millilitres the cup holds.
Smell the dry grounds.
Pour water just off the boil to the rim, start a clock, and put your nose over the cup.
At four minutes, push the crust back with the spoon and smell again.
Skim the foam.
From about ten minutes, taste with a spoon, slurping.
Keep tasting for another ten minutes as it cools; cold coffee shows defects that hot coffee hides.
Always taste two at once
The highest-leverage tasting habit I know.
A coffee alone has nothing to be compared with.
Two side by side show their differences, even to a damaged nose, the way two shades of white paint match on the chart and part company on the wall.
Differences are easy; absolutes are hard.
Three words
Three words and a score for how much you liked it; no paragraph.
The fruit names come later, or never, and either is fine.
Then triangulate
Three cups, two the same and one different; find the odd one.
A real module in the professional tasting exam.
Humbling, and the fastest way I know to learn how much you can actually perceive.
Where the vocabulary came from
The words on the bag sound like poetry and behave like engineering, and their history begins in the seventies, when a chemist at a university in California joined the wine faculty, the first woman on it, and found that tasters had no shared framework, so she built a wheel of aroma terms and then, crucially, a set of physical reference samples, so that when two people said blackcurrant they were smelling the same blackcurrant.
Coffee did the same a generation later, when a research institute built a lexicon of over a hundred flavour, aroma and texture terms, each tied to a reference you can buy and smell, and the famous flavour wheel was redrawn on it with a shape that was computed, since dozens of experts sorted the terms by similarity and the geometry came out of their sorting, so neighbours on the wheel are terms that trained people perceive as close.
The professional coffee tasting qualification expires after three years, because the trade treats a palate as an instrument that drifts out of calibration like the pressure gauge on a boiler, a humility I have not found in any wine qualification, and I think coffee has it right.
One small study tested the jar of beans at the perfume counter. Coffee barely beat breathing air, and lemon beat both. Not settled, but the only direct test I could find.
One myth, since it is in every perfume shop
The jar of coffee beans on the perfume counter is there to reset your nose between scents, and one small study tested it by asking people to tell perfumes apart after sniffing coffee, after sniffing lemon and after plain air, and coffee barely beat air while lemon beat both, and one small study settles nothing, though it is the only direct test I could find. The perfume trade uses coffee to reset a nose, and the researchers who study damaged noses use coffee as the hardest thing for a nose to get right, and how can both be right about the same smell?
I will never know exactly how much came back, because there is no meter for it, and what I do know is that this month, in cupping bowls on a counter surrounded by boxes, I could tell two Ethiopian coffees apart side by side, one bright as a squeezed lemon and the other heavy as plum jam, which I could not have done before I lost anything. The loss is what taught me to pay attention, and whether that is a lesson or only a thing that happened to one man in one winter, with the boxes rising around him and a country waiting at the other end of the flight, I still cannot say.
If you want one thing to do this morning:
Make two coffees instead of one, from two different bags.
Drink them side by side as they cool.
Write three words for each.
You will find that you can taste more than you thought, and the note on buying will tell you which two bags to start with, and the note on roasting why they smell the way they do.
The next note will come from another country, from a kitchen with a steel filter that has been in the family longer than I have.
Questions this note answers
How do I learn to taste coffee?
Taste two coffees side by side rather than one alone, keep tasting as they cool, slurp so the aroma reaches the back of your nose, and write three words and a score. Differences are easy to notice; absolutes are not.
Why does coffee smell bad after Covid?
A 2022 study found that the molecule which gives coffee its roasted smell is the most common trigger of distorted smell in people recovering from the virus. Their noses pick it up first and misread it. Most people improve over months.
Does smell training work?
For some people. In the original study about a quarter of those who trained twice a day for twelve weeks improved meaningfully, against a small share of those who did not train. The standard four scents leave out roasted smells, so training with coffee is a reasonable addition.
