Bitter Almond Ice Cream

Time 1 hour
Yields Serves 8
Print RecipePrint Recipe

To meet Paul Schrade, a tall, white-haired 77-year-old with a gently bemused smile, you’d never suspect that he’s obsessed with a poisonous nut. Mention the bitter almond, however, and the retired union organizer won’t stop talking about how--on a culinary tour of Sicily in 1990--he fell in love with its powerful, unique flavor, which gives marzipan and almond milk their characteristic taste. Even after he was told that raw bitter almonds contained a form of cyanide and were illegal in the Unites States, Schrade was fascinated.

“I thought, ‘European chefs make good use of bitter almonds for cooking and baking--why shouldn’t we?’” he says.

Through his second career as a bakery consultant and forager for Campanile restaurant, Schrade sought to spur a revival of the ancient Mediterranean flavoring in California. Undeterred, or perhaps intrigued, by the nut’s sinister reputation--spread by mystery tales in which the detective sniffed the odor of bitter almonds on a cyanide victim’s breath--he sleuthed relentlessly for sources and information.

He learned that most of the original wild species of almonds were bitter, but that, as the nuts came into cultivation thousands of years ago, farmers began concentrating their crops toward sweet types, the kind grown today in California.

A recessive gene causes bitter almond trees to produce in their shoots, leaves and kernels a toxic compound called amygdalin, which serves as a chemical defense against being eaten. When amygdalin is moistened, it splits into edible benzaldehyde, which provides an intense almond aroma and flavor, and deadly hydrocyanic acid, a fast-acting inhibitor of the respiratory system.

The lethal dose of raw bitter almonds depends on the size of the nuts, their concentration of amygdalin and the consumer’s sensitivity. But scientists estimate that a 150-pound adult might die from eating between 10 and 70 raw nuts, and a child from ingesting just a few.

In any case, although it may be safe for most adults to nibble a raw bitter almond to experience its intense flavor, that would be unpleasant to most people. The nuts are not meant to be eaten as a snack food like regular almonds: They’re used as a spice, like nutmeg or cinnamon.

Schrade, who studied organic chemistry at Yale, learned that because hydrocyanic acid vanishes into the air when heated, cooking destroys the poison in bitter almonds and allows them to lend their flavor to a wide range of dishes, both traditional and modern.

In the course of his explorations, Schrade found several California chefs eager to cook with bitter almonds. At the center of this informal network is Tim Woods of Echo restaurant in Fresno, famed for his zealous use of local ingredients.

Since bitter almonds are usually not available commercially, he harvests his nuts from nearby wild and backyard trees, and uses them to add a pleasing bite to the richness of bread pudding with caramel and to stone-fruit cobblers. He also shares his supplies with Sean Lippert, formerly chef of Across the Street in New York, for her bitter almond granita, and with Judy Rodgers of Zuni Cafe in Berkeley and Kim Boyce, pastry chef of Campanile, who both use the nuts to flavor panna cotta and ice cream.

Until recent decades, most Mediterranean almond orchards were grown from seed, and the shuffling of genes resulted in a mix of bitter almond trees among the sweet. Growers liked to keep a few bitter trees around because they helped to pollinize the sweet varieties. The inclusion of bitter nuts gave snackers occasional unpleasant surprises, but they deepened the flavor of marzipan, almond milk and glazes for cakes. In Italy, bitter almond paste was traditionally used to make crisp amaretti cookies, and bitter almond extract flavored amaretto liqueur. In Greece, bitter almonds are used in soumada, a sweet syrup.

There’s little large-scale cultivation of bitter almonds left in Spain and Italy, mostly just scattered trees remain, but it is still possible to buy raw bitter almonds at European specialty markets. Morocco and Iran now lead in commercial production of bitter almonds.

In the United States, the lack of clear information about bitter almonds’ legal status has squelched their cultivation, trade and use. No stores regularly stock bitter almonds, so cooks seeking them have had to rely, like Woods, on seedling trees growing wild along streams, roads and railroad tracks.

“I don’t know if I should sell them or not,” says Bill Fujimoto, owner of Monterey Market in Berkeley, which carries bitter almonds occasionally. “I don’t leave them out on the counter. I sell them only when people who know bitter almonds ask me for some.”

Over the years, Schrade made dozens of inquiries to federal and state health authorities about the legality of bitter almonds, but never received a definitive answer. Recently, however, a friend steered him to a Food and Drug Administration Web site that states, “Because of their toxicity, bitter almonds may not be marketed in the United States for unrestricted use.” The agency’s regulations do, however, allow almond paste and extract manufacturers to use the nuts as long as their products do not contain more than minute, safe levels of hydrocyanic acid.

The FDA clarified the agency’s position recently, saying that it would allow bitter almonds to be shipped interstate to professional chefs and bakers, as long as their dishes were cooked to be nontoxic. But the agency said it would take “appropriate action” against vendors found to be selling bitter almonds to the public in such a way that they could easily be confused with regular almonds. These actions might include issuing a warning, or seizing the product.

The FDA regulates interstate commerce in foodstuffs, but bitter almonds grown and sold within California fall under the jurisdiction of the state’s Department of Health Services, which takes a less restrictive approach to retail sales. James Waddell, acting chief of the department’s Food and Drug Branch, says that the agency has no specific regulation covering bitter almonds, but that the nuts could be sold in accordance with its rule for bitter apricot kernels, which requires packages to bear labeling stating: “may be toxic; very low quantities may cause reactions.”

The upshot is, California growers and vendors are permitted to sell properly labeled packages of bitter almonds to California consumers.

This is good news to Rusty Hall, one of Schrade’s discoveries, who grows both sweet and bitter almonds, which he sells at farmers markets and by mail order. Virtually all the state’s sweet almonds come from vast irrigated orchards of densely planted trees in the Central Valley, but at his ranch near Paso Robles, Hall quixotically tends an ancient orchard that he dry-farms, which he is convinced gives his sweet almonds more concentrated flavor.

On a bright September morning in the middle of harvest, Hall surveyed his widely spaced trees, their roots reaching deep into the rolling hills. Central Valley farmers harvest mechanically, but Hall and his workers gathered the crop by hand, using long poles and rubber mallets to knock down the almond fruits, which resembled thin-fleshed, split-open apricots, onto tarps.

They carefully avoided half a dozen bitter almond trees, which were flagged with red surveyor’s tape tied to their branches. Almond orchards in the area were grafted on almond seedling rootstock, explained Hall, and some of the rootstock, as usual, turned out to be bitter almond. Sometimes the sweet almond graft didn’t take, or the scion later died, leaving the bitter rootstock to develop into a tree.

It’s not hard to find bitter almond trees in local orchards, he added, but tough to convince a processor to hull and shell the nuts: California sweet almond growers, who harvested 525,000 acres last year, regard bitter almonds as contaminants. Therefore, said Hall, he’d have to wait until the end of the season to pick and process his bitter almonds separately.

Because of the almond industry’s fear of bitter nuts, it seemed impossible that anyone would dare to grow them commercially in California. But a little more than a year ago, Schrade announced triumphantly that he had found such a source: Thomas Vetsch, a Swiss American grower from Bakersfield, had a small planting of 3-year-old bitter almond trees, which were just starting to bear, as a sideline to his 1,200 acres of sweet almonds.

On a blustery day last March, with his almond orchards in full bloom, Vetsch gave instructions to a beekeeper and shared his passion for almonds.

“Just look at this,” he said, gesturing excitedly at the sea of white blossoms. “This is the glory of the world, the wonderful sweet fragrance, the bees flying around. Hear that buzz? That’s what you want to hear: strong bees,” he said, his eyes gleaming.

Vetsch and his wife, Kim, had fallen in love under an almond tree, he said. The almond project was their dream. In addition to selling bulk almonds commercially, they have a smaller venture, Mandelin, that manufactures almond pastes. A perfectionist, he had originally planted some bitter almonds so as to be able to control all the ingredients for the pastes, normally made with imported oil of bitter almond.

But when he was asked to show a visitor his bitter almond trees, his expression darkened. At a recent almond industry conference, rumors that someone in Kern County was growing bitter almonds had caused a sensation. Soon thereafter, Vetsch had fired up the chain saws.

“It’s over. It’s history. I have no more bitter almonds,” he said vehemently, pointing to a bulldozed section with a pile of uprooted trees. “In Europe they love bitter almonds, but they will never be grown here. Americans are so sue-crazy--if someone feels a little off, the first thing they do is call a lawyer. I can’t put the whole farm in jeopardy.”

Vetsch said he hadn’t given up his quest for European-style, full-flavored almonds, however. At his office and factory in Bakersfield, he offered a taste of nuts higher in oil and richer in flavor than American almonds.

“That’s as close to bitter as it gets, but with no poison,” he said. “We use it in our almond pastes.”

Asked to name the variety, he said, “What? Do you think that I’ll tell my secrets?”

When told of the trees’ demise, Schrade was disappointed but philosophical. It will take further work to remove the stigma of bitter almonds, he reflected.

As much as he loves the flavor the nuts provide, he said, “Sometimes when I’m on the treadmill at the gym and I feel a bit peaked, I wonder: ‘Am I getting old? Or is it the bitter almonds?’”


Grind the almonds in a blender or food processor, then place them in a saucepan with the half-and-half. Heat to just under a boil, turn off the heat and let sit for 30 minutes. Strain the mixture through a very fine strainer or cheesecloth. Return the mixture to a clean saucepan. If using extract, add it to the custard after it’s been cooked with the eggs.


In the bowl of an electric mixer, beat the sugar and egg yolks together until thick and lemon-colored. With a whisk, mix the yolk and sugar mixture into the half-and-half. Cook over low heat, stirring constantly, until custard coats a spoon, 10 to 15 minutes. Chill for 1 hour, add the almond extract and freeze in an ice cream maker according to manufacturer’s instructions.

Tim Woods, chef and co-owner of Echo restaurant in Fresno, delights in the use of local ingredients. He gathers bitter almonds from a few old trees in his neighborhood, both for his own use and for other chefs. Serve this ice cream with cherries, peaches, nectarines or apricots.