Inhaling the intoxicating aroma of fresh basil or biting into a ripe cherry tomato fresh off the vine and bursting with sweetness and earthy flavor is one of life’s simplest pleasures.
But keeping these perishable products at their optimal freshness once they arrive home is the real challenge.
If you store your fresh food incorrectly, you can end up throwing it away, a waste that is a huge environmental problem.
Every year more than a third of the food grown in the world is thrown away. In the United States, food waste is on the rise, according to recent data from ReFED, a national nonprofit organization working to end food loss and waste. Wasted food represented around 38% of the total food supply in 2021, worth approximately $444 billion, according to ReFED (about €413 billion).
In Spain, it is estimated that each Spaniard throws away about 28 kilos of food per year for a total of 1,245 million kilos wasted annually in the country as a whole.
These tried-and-true methods can help you maximize the flavor, texture, and shelf life of your fruits and vegetables and avoid food waste.
A number of conditions can influence the freshness of the products in our refrigerator, such as temperature, the amount of water available for the growth of microorganisms, humidity, ethylene gas production, air flow and packaging, explains Brian Chau, a food scientist and mushroom fanatic, who runs Chau Time, a food consulting company.
Take a walk through the produce aisle of your supermarket. You will notice that many products are wrapped in a plastic sleeve or wrapper, such as mushrooms. Mushrooms are 70% to 90% water, and if stored in a plastic environment, condensation forms.
“Storing mushrooms in plastic increases the rate of decomposition, because they are constantly in a very humid environment,” explains Chau. “What you have to do when you get home is transfer the mushrooms to a paper bag, because paper is more porous.”
And because a paper bag creates less humid conditions, you slow down the aging process and keep the mushrooms dry without removing their moisture content.
Another popular storage trick is to wrap leafy greens in kitchen paper and store them in the refrigerator to prolong their shelf life.
“What I do is wrap the lettuce in kitchen paper and wrap it in aluminum foil,” Chau explains. “This way, the lettuce loses some surface area, but not so much that it becomes a dehydrated piece of lettuce.
A similar approach can be taken with aging herbs.
When they are fresh, you can trim the stems and put them in a jar of water to prolong their shelf life.
However, once they start to show signs of deterioration, Chau recommends lining a high-sided aluminum tray with kitchen paper and placing the herbs on top, covered with more kitchen paper and a final layer of aluminum foil.
This layering of herbs, kitchen paper and aluminum helps control humidity and ensure freshness.
“With this aluminum tray, air flow is reduced because the walls are higher and everything stays cold,” explains Chau. “At the same time, what you’re trying to do is allow some of the moisture to escape to reduce and eliminate condensation, which leads to decay.”
Storing food at room temperature varies depending on where you live and the time of year. If you are in a tropical or very humid environment, you can increase the rate of spoilage, simply because there is more moisture trying to penetrate the food, which increases its spoilage.
And while most fruits and vegetables can be stored in the refrigerator, keep onions and garlic in a dry, well-ventilated environment, out of the refrigerator. Frigid temperatures can cause garlic to mold, and at colder temperatures, the starches in onions convert to sugar more quickly, leaving them soggy and mushy.
For tomatoes, the degree of ripeness at the time of picking determines whether they should be kept on the counter or in the refrigerator. Tomatoes are often picked unripe, so between the farm and the supermarket they ripen over time, ideally reaching their optimal ripening point when they arrive at the supermarket, Chau explains. He recommends putting fully ripe tomatoes in the vegetable drawer of your refrigerator, designed to keep produce fresher.
“Another thing I like to do with tomatoes picked off the vine is to invert the tomato and cover where the vine was attached,” he says. “That is the point where it is most vulnerable to moisture loss; you can use food tape, wax or even kitchen paper to cover this vulnerable point and prolong its life.”
Lastly, look at what foods you store together.
Many fruits and vegetables release ethylene gas, an odorless, colorless gas that occurs naturally in produce and is known as the “fruit ripening hormone.” The best-known producers are bananas, but cantaloupe, tomatoes and avocados are also heavyweights in ethylene production.
Some fruits and vegetables produce ethylene gas to trigger their own ripening process, but if nearby vegetables, such as carrots, broccoli, and cucumbers, are exposed to the gas, they will begin to age and deteriorate. That’s why it’s important to keep some fruits and vegetables separate.
“You don’t want to store apples and bananas together because it creates a cyclical loop in which they age much faster together,” explains Chau. “But, if you put apples in with berries in general, then you don’t necessarily have that accelerated rate of degradation or decay.”
Food fermentation is the process of using microbes, such as yeast or bacteria, to preserve food and change its flavor and texture. It has been an effective way to preserve food for millennia.
Ancient Koreans took advantage of the cold of winter to ferment vegetables by burying them in the ground in ceramic jars called onggi. In Babylon, beer was made by fermenting dates with water. And in Anatolia (the Asian part of modern Turkey), milk stored in sheepskin or goatskin bags was fermented to create yogurt. Today, restaurants like Denmark’s three-Michelin-starred Noma use these same tactics to avoid food waste.
“The fermentation lab is the last room before you get to the garbage room,” says Kevin Jeung, head of research and production at Noma Fermentation Laboratory. “We’re kind of the last bastion to use an ingredient before it’s thrown away.”
One example of how Noma Fermentation Laboratory avoids waste is through a partnership with its satellite bakery, Hart Bageri. Instead of throwing out unsold rye bread at the end of the day, the bakery freezes and stores the surplus to send to Noma Fermentation Laboratory, where it is ground and flavored with barley koji and salt. After fermenting for a few months, the bread takes on a new shape as a meaty, sweet and rich miso paste. The laboratory returns this fermented product to the bakery to add to future loaves of bread.
Don’t know where to start fermenting foods at home? Jeung recommends starting with simple projects, like curing olives in brine.
“I like to think of fermentation not as a fad, but as a reconnection with our past and with nature,” writes Barry Tonkinson, vice president of culinary operations at the Institute of Culinary Education: “When you ferment, you are simply following a framework for fermentation. magic of nature and on the other side, if you are patient, there is a whole world of culinary opportunities ready to be explored.