Index
How it started
What shall we make for our first dessert?
We stood around inside Atelier KOTO as we pored through the recipe books that contain our entire history, letting them spark memories of the flavors that have stayed with us.
First, we turned to our creed for guidance: to serve dishes that do not rely on premium ingredients.
We use the phrase “premium ingredients” to refer to ingredients that are graded, such as A-grade wagyu or tuna. There is nothing wrong with such ingredients, but what we really want is to prove our prowess with ingredients that are easily available to the average household. After all, it is the job of a chef to create spectacular flavors from even the most everyday ingredients.
For this dessert, we were looking for a key ingredient that was cultivated with care in a healthy environment and was, of course, delicious. If the ingredient evoked feelings of early summer, even better.
And so began the quest for an ingredient that would meet these criteria.
The mad scientist
One day, as we were busying ourselves with this quest, we received a message from Hidekazu Kan of Citrusfarms Tatemichiya. Kan’s lemon farm overlooks the Seto Inland Sea from its perch on Ikuchijima Island in Onomichi, Hiroshima.
“Agriculture is a science,” says Kan, who has dedicated himself to the challenge of growing delicious lemons by questioning the conventional wisdom surrounding citrus cultivation. As chefs who also feel a similar sense of responsibility when it comes to food, his philosophy strikes a chord with us.
Kan describes his approach in a very simple way: “nothing extra.”
That is to say, he doesn’t use any unnecessary fertilizers. Kan created a soil chart for his land by analyzing its soil, then scientifically calculated the appropriate amount and blend of nutrients necessary to grow delicious lemons. He has found that his soil responds best to mineral fertilizers.
This is exactly what we were looking for: someone who cares about both his crops and the environment in which they are cultivated.
Among the many things that Kan has taught us, one thing that stands out is his views on pesticides and other agricultural chemicals.
“Chemicals are not evil,” says Kan, who does not disavow the use of pesticides. “They are merely tools used to kill pests and sterilize crops.” That is why he grows “chemical-free” lemons, for which he uses no chemicals at all, but also “low-chemical” lemons, cultivated using less than half the normal amount of chemicals.
As a society, we are easily swayed by the words “pesticide-free,” but whether pesticide-free foods are actually healthier or better-tasting is an open question. After all, taste is such a subjective sense. Have we gotten so caught up in words that we’ve forgotten this basic fact?
We felt that Kan’s lemons would cause a sensation, so we replied to his message, asking him to deliver everything that he had in stock to our kitchen in Tokyo. We knew that a dessert based on lemons grown with such care and diligence was sure to make people rethink their attitudes about food.
Fête du citron
One of the greatest works of 20th century French literature is Marcel Proust’s In Search of Lost Time. The book famously contains a description of the author tasting a madeleine cake dipped in tea. Like a bolt from the blue, the aroma brings back a long-forgotten memory of his childhood days, when he used to eat madeleines in the same way.
This has come to be called the Proust Effect. Chef Koto says that the moment he came face to face with the cardboard boxes full of Kan’s lemons, he was struck by his own madeleine moment. The gentle citrusy scent wafting through the kitchen immediately brought him back to his days spent working in a restaurant in Provence in the south of France.
For the people of Provence, lemons are everywhere. Once winter ends, not a day goes by that you don’t see them in restaurant kitchens, on tables, and even in ordinary homes.
There is no better way to experience Provence’s preoccupation with lemons than a visit to Menton, a city perched on France’s southeastern border, for its annual Fête du Citron in February. During the lemon festival, the sun-drenched seaside town becomes filled with some 150 tons of lemons, turning the whole town a cheerful shade of yellow. It is a reminder of how closely intertwined the lemon is with the lives of the people in this region.
The lemon harvest ends in early spring, but it is in summer that these fruits are most sought after in Japan. Perhaps it is because lemons have a cooling effect on the body, whisking away the fatigue brought on by sweltering heat. Whatever the reason, we knew that the lemon, with its strong association with summer, was the ingredient we were looking for. As soon as we saw Kan’s delivery, we were sold.
Confiture
Now, the next question: what to make with these lemons? We cut one in half and found it to be surprisingly juicy.
When we think about lemon desserts, we often think of tarte au citron, a lemon tart that is an old staple in France, sold everywhere from supermarkets to Michelin-starred restaurants. Its intense lemony flavor makes it a perennial favorite, but we thought there must be a better way to show off Kan’s juicy lemons to the fullest.
Then it came to us: lemon jam.
It takes a surprising amount of time and effort to make jam. First, each of the 400-plus lemons we received from Kan had to be cut in half and pressed. One lemon at a time, we removed the remaining flesh with a knife and then placed the rind into a pot of water to boil. We repeated this process five times, adding sugar all the while, until finally we had our jam.
We would be lying if we said we had no reservations about embarking on this time-consuming process. Still, spending time and effort to prepare each ingredient with care is one of the most important things that we must do as chefs. This is no less true when it comes to sweets.
Our efforts paid off in the end because the lemons—simmered slowly over a long period of time—yielded an incredible jam. The color, aroma, and viscosity had transformed utterly from those of the original fruits.
And that led us to our next revelation: that this luxurious jam would knead beautifully into a gâteau de voyage!
We could easily picture a couple on a date, sharing a lemon cake between the two of them.
Gâteaux de voyage
Back in 17th century France, the Marquise de Sévigné had a request for her pastry chef. Because she traveled between Brittany and Versailles several times a year, she wanted him to invent a cake that would not spoil and would be easy to eat on the road.
And so, he created the gâteau de voyage—literally, a travel cake. The concept is straightforward. Gâteaux de voyage are made with standard pantry ingredients and have a shelf life of about two weeks at room temperature. Since they are easy to package once cut and are easy to consume on the road, they are great for sharing with a group. Cake with lemon jam is a quintessential gâteau de voyage.
We have found that the gâteau de voyage is well-suited to the traditional Japanese culture surrounding food souvenirs. Whenever we go to see family, friends, or mentors, we bring a sweet little something with us. Often, the recipient invites the giver to share the treat with them. It can even be a topic of conversation, so something that is hard to find or currently in season is considered a chic choice.
There is no greater joy than to see a sweet souvenir—whether a snack brought home from a trip or a treat you purchased for a loved one—inspire moments that people will treasure for the rest of their lives.
Our recipe
Our recipe books listed a recipe for a lemon gâteau de voyage, but it would not do to simply follow the existing recipe. After all, it is the ingredients that make the recipe.
Trying Kan’s lemons showed us how much the sugar content, acidity, and water content of a lemon can vary from year to year, depending on the climate and time of harvest. This particular batch was harvested in April 2024. Lemons are sweetest in February and March, so this late-season harvest had time enough to mellow in both sweetness and acidity. And so began the process of testing various gâteau de voyage recipes to find one that suited the character of this particular batch.
Gâteaux de voyage are known for their moist texture, which normally comes from butter. However, we found that the lemon jam tasted better with less butter and a higher egg content. To make sure the batter was properly emulsified, we had to pay close attention while mixing and control the temperature of the eggs. Gradually, our recipe took on its final form.
It was especially important to add plenty of limoncello and to allow the jam to soak into the batter slowly and thoroughly while in the oven. In the end, we had a cake that tasted even better a few days after baking than when it first came out of the oven.
A piece of cake
We had just one decision left to make—how to sell our gâteau de voyage. We decided it worked well as a loaf.
When a cake is sliced to show the evenly distributed ingredients, it certainly does look appetizing. However, we find it can also be mechanical and uninspired. The marbled streaks of lemon jam in our cake go every which way. It may seem random and uneven, but it’s also why the texture and flavor differ slightly depending on how it’s been cut.
Some people like a thick, chunky slice, while others prefer a thin one. Some may even find that they want something different depending on the time of day. Maybe a thick slice is better in the morning, served for breakfast with a cup of strong black tea, but a thin cut pairs better with an after-dinner digestif or cup of Chinese tea. We think this is a gâteau de voyage that encourages experimentation—it can provide an infinite number of variations in taste and texture based on how it is cut and with which beverage it is paired. The little pieces of lemon zest in the jam add yet another element that can transform the cake’s flavor.
We hope you’ll find a combination that becomes your favorite.
