Dehydrated food goes from hiking to haute cuisine

“The line we’re riding is Grandma’s potpourri basket.”

Ever since fifth grade, when I made beef jerky with Mrs. Swanagan in a trailer behind my elementary school, I've been fascinated by the process of creating inedible food out of perfectly good ingredients by removing all of their moisture. Dried fish, fruit leather -- the list is endless. However, in the past few years, chefs at high-end restaurants have been rescuing the technique of dehydration from River and Dawn's camping supplies and elevating it to haute cuisine.

Take Il Fiorista, a new boutique and Mediterranean-inspired eatery in Manhattan that specializes in edible flowers (il fiorista means "the florist" in Italian). Everything on the menu incorporates flowers, whether it's geranium aioli or duck cappellacci with rose petal pasta.

Dehydration "is a direct link for us to be able to preserve the integrity of the flavors of flowers," said Executive Chef Garrison Price when I met him at the restaurant on yet another rainy, cold New York winter afternoon. Instrumental jazz verging on elevator music chimed from the speakers as well-dressed women in their thirties chatted at a few tables, and the restaurant's accountants conferred conspiratorially at the bar. The space felt airy and upscale, with the main wall sporting a colorful mural and the boutique in front boasting a table of unusual flower arrangements.

"The line we're riding is Grandma's potpourri basket," Price said as we walked into the kitchen. "We don't want people to be smacked in the head with flowers."

Dehydration is one of the oldest ways to preserve food: Experts have traced it back to 12,000 BC, when Middle Eastern and Asian cultures were drying foods in the sun. At the end of the 18th century, the French invented a way to dehydrate using hot air, and in World War II, dehydrated foods were famously used in American soldiers' rations. It's a surefire way to lengthen the lifespan of an ingredient or dish by months or even years, plus it makes food lighter and easy to carry.

"We don't want people to be smacked in the head with flowers"

As molecular gastronomy has become popular over the past few decades, so have all sorts of techniques to alter the taste, texture and appearance of everything edible; dehydration is one of the easiest ways to do it. Chefs can concentrate an ingredient's flavor and make it look gorgeous. Perhaps most importantly, dehydration allows chefs to use seasonal ingredients year-round, preserving them so that we can have everything from flavorful squash blossom pasta to bright strawberry frosting in the winter.

Back at Il Fiorista, Price had offered to show me how he makes his hibiscus harissa for the dinner menu's prawns and polenta with grilled bok choy. A veteran of Jean Georges' and José Andres' corporate teams, the earnest, thirtysomething chef punctuates his speech with phrases like "negatron" and "saweeeet!"

Price led me into the walk-in freezer to show me how the restaurant ferments tomatoes and chilies. Think big buckets of pureed ingredients with some salt added. Give them a little time, they'll give you a little funk. They're the secret sauce in the, um, sauce, which mainly consists of dehydrated versions of those fermented purees, olive oil and some spices.

We went down to the basement to borrow a few flowers from their large cooler area, then headed into the pastry kitchen slash fermentation and dehydration laboratory with our goodies. Hibiscus is out of season, so Price had nabbed red and pink peonies from a private corporate event at the restaurant the previous week. (Il Fiorista's resident florist, Mindy Cardozo, describes flowers as "little corpses" to highlight that they're already dead and in various stages of decomposing when we put them in vases and vodka.)

First he soaked the flowers in water to remove any unwanted brown matter, then carefully plucked the petals from the stem, spread them in a single layer on a dehydrator tray and popped them in the Excalibur-brand machine to dehydrate for six hours at 95 degrees. Why 95? "That's a temperature I've found to be very consistent to maintain the color of what we're doing," he explained.

I'd learn later that no one really knows the "right" temperature to dehydrate anything, and that even the instruction manual for my at-home machine said that "the only way to become proficient is to dry, dry and dry some more!" Also, while it's entirely possible to dehydrate in the oven rather than in a fancy single-use machine, most ovens don't go below 100 degrees. Even if they did, I'm not sure I'd recommend leaving your oven on for 16 hours or so to make salmon jerky while you, say, sleep, walk your dog and go to the office.

As we waited for the water content of the flowers to lower, Price pointed out jars and buckets full of dehydrated and fermenting ingredients that he planned to use in the future: preserved lemons, concord grape and champagne vinegar, marigold petals in Everclear, dried calendula petals and lily flowers. All this while his busy team prepared for dinner service. "How many pounds of tuna do you want to get?" one person asked as another two attempted to make bread in a tiny oven after the restaurant's $22,000 professional version broke down. Ah, the day in the life of a chef.

"The only way to become proficient is to dry, dry and dry some more!"

Meanwhile I taste-tested Il Fiorista's dried forget-me-nots -- used in shortbread cookies and wildflower fritters -- against local spice shop Kalustyan's. The buds' purple leaves reminded me of Prince on the cover of Purple Rain, but alas, neither variety tasted as honeyed as his voice. Think planty and chewy.

Fortunately, the dried saffron flower that Price handed me made up for my misstep. It's highly unusual to see the whole flower, since we typically only have access to threads of saffron (the flower's stigmas). I hadn't realized that each flower has only three threads, which explains the spice's high price. The whole shebang on its own tasted slightly sweet and delicate, with a hint of addictive bitterness.

Price pulled a glass jar off a high shelf and urged me to put my nose in it. The dried basil smelled as fresh as summer. Using the basil, he showed me how to turn dried flowers into a powder, like I'd be doing with the hibiscus for the harissa: Put the leaves or petals into a Vitamix with flat blades, then let it whir till you have a fine powder. Do not, as we did, stick your head directly next to it when you remove the lid, as the pungent dust will puff into your nose and lungs, causing a reaction worse than GloZell's to the cinnamon challenge.

After we finished hacking up herbs, I went on my merry way. I'd bought a Nesco dehydrator (at only 1/5 of the cost of a restaurant-quality device), and it was all pristine and white at home, just waiting for me to mess it up.

Whereas Price's looked like a run-of-the-mill wine fridge, mine resembled a small igloo for a miniature sled dog or a plastic version of Amy Winehouse's beehive hairdo. He'd recommended pouring the tomato and chili purees into two pans then placing them in the dehydrator, but my round receptacle wouldn't accommodate that plan.

Why not use foil, then? I layered a few pieces on to two levels of the Winehouse beehive, then carefully dribbled in the purees I'd made from canned, diced tomatoes and chipotle peppers in adobo. Those ingredients are practically the same as heirloom tomatoes and fresh chilies that have been fermented in salt and water, right?

I turned on the dehydrator and let a wave of noise wash over me -- I hadn't expected this, but it was louder than the grinder I use to make chocolate at home. I usually stow that in my NYC-sized closet for 24 hours or so when it's working away, but the Winehive was much too large.

Recipe: Harissa Paste by Il Fiorista

dehydration tech


  • 1/4 cup sweet paprika

  • 2.5 tablespoons hot paprika

  • 2 tablespoons whole coriander seed

  • 1.5 tablespoons whole caraway seeds

  • 1.5 tablespoons whole fennel seeds

  • 1.5 tablespoons whole black peppercorns

  • 2 teaspoons tablespoons whole cumin seed

  • 4 cups extra virgin olive oil

  • 1 preserved lemon, seeds removed

  • 1/2 cup lemon juice

  • 1 cup white onion, coarsely chopped

  • 1 cup whole cloves peeled garlic

  • 1/2 cup dill, tough stems removed

  • 1/2 cup parsley, tough stems removed

  • 1/2 cup marjoram, tough stems removed

  • 1 cup mint, tough stems removed

  • 2 cups chili paste (see below)

  • 2.5 tablespoons tomato paste (see below)

  • 2.5 tablespoons honey

  • 2.5 tablespoons powdered dry mint

  • 2 tablespoons kosher salt

  • 2 tablespoons red wine vinegar

  • 1.5 tablespoons sumac powder

  • 1 tablespoon urfa biber

  • 3 tablespoons powdered dry hibiscus

In a spice grinder, combine the sweet and hot paprikas, coriander, caraway, fennel, peppercorns and cumin and process to a fine powder.

In a small saucepan set over low heat, gently warm oil. Add the spices and cook, swirling occasionally, until very fragrant, 10 minutes.

While the spices are blooming, in a small food processor or blender, combine the preserved lemon, lemon juice, onion, garlic, dill, parsley, marjoram and mint and process to a rough paste.

Remove the pot from the heat, then whisk the herb mixture into the spiced oil.

Return the pot to low heat to warm slightly, then whisk in the sweet chili paste, tomato paste, honey, dry mint, salt, red wine vinegar, sumac, urfa biber and hibiscus powder. Bring the mixture up to a simmer, stirring frequently to prevent scorching.

Transfer the mixture to a food processor or blender and process until smooth and emulsified then adjust the seasoning.

Tomato Paste

  • 12 whole plum tomatoes

  • 4 tbsp salt

Blend tomatoes to a smooth puree -- this should yield two quarts of tomato puree. Mix in salt.

Place the tomato puree in a glass or plastic container covered with cheesecloth and allow to sit at room temperature for 24 hours to allow the tomato puree to lightly ferment.

Place the fermented tomato puree in a shallow pan in an even layer about 1.5 inches thick. Dehydrate at 145 degrees F for 12 to 16 hours, until most of the water has evaporated and you have a wet, tomato-paste consistency.

Refrigerate the tomato paste until you are ready to use it.

Chili Paste

  • 5 pounds red Anaheim chilies, stems and seeds removed

  • 4 tbsp salt

Blend chilies to a smooth puree. Add as much water as needed to the puree to yield two quarts total. Mix in salt.

Place the chili puree in a glass or plastic container covered with cheesecloth and allow to sit at room temperature for 24 hours to allow the tomato puree to lightly ferment.

Place the fermented chili puree in a shallow pan in an even layer about 1.5 inches thick. Dehydrate at 145 degrees F for 12 to 16 hours, until most of the water has evaporated and you have a wet, tomato-paste consistency.

Refrigerate the chili paste until you are ready to use it.

Six ear-splitting hours later, I decided I couldn't wait the 16 hours Price had instructed. I turned off the dehydrator and opened it up, hoping to find thick pastes of both ingredients. Instead I'd made... paint! Van Gogh himself would have been envious of the texture of this substance, which had shellacked itself on to the foil as if it were the makings of a masterpiece.

Abandoning one disaster for another, I moved on to the flowers. Like my canned ingredients, who needed fresh hibiscus or peonies from local farms when I could get perfectly nice bouquets at my local bodega, flown in straight from Central and South America? Front and center in the bouquet bloomed a red rose, and since rose was one of the first prized flavorings in the history of the world (along with salt, sugar and, eventually, vanilla), it called out to me.

Before I dehydrated them, the rose petals tasted a bit like chewy plastic, but three hours at 95 degrees really concentrated the aroma of my great grandma Sara, with more than a hint of bitterness from the pesticides most likely used on the crops. (I'd washed them as Price had instructed, gently in a bowl of cool water, but alas.)

I'd made... paint!

Honestly, I'm amazed I let the whole thing brew for three hours, because half an hour in, the pollen being distributed throughout my house via the dehydrator's open-air tunnel gave me the wickedest allergy attack I've had since I put my face in a litter of kittens. I'm also pretty sure I dislocated something with the force of my sneezes. But once my eyes had dried, I powdered the petals in a coffee grinder, which, with its stale bean crumbs, added a nice depth of flavor.

Then it was time to try the tomatoes and the chilies once again, making sure that I put much thicker scoops into the machine this time. And it worked! After only three hours in the Winehive, the pastes were ready to blend with the powdered flowers and the almost two dozen other ingredients in the recipe, including urfa biber, a kind of Turkish chile that can only be found at approximately one and a half spice shops in New York City. Price's recipe makes boatloads of harissa, but after combining everything, I had a scant cup.

Sure, I could have made a dish imitative of Il Fiorista's, but since I'd mastered the art of dehydration, I wanted to push it to the next level. So if my neighbors smell something funny in the hallway, it's probably the last piece of my magnum opus: dehydrated prawn strips for my ingenious harissa "fruit" leather over polenta pellets. Truly high class.

Images: Il Fiorista (flowers spread, prawn and harissa); Megan Giller (dehydrator, contained flowers)

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