The almond you buy at the store is not really a nut. It is the seed of a fruit closely related to the peach and plum.1Wikipedia. Almond What you can eat depends mostly on when the fruit is picked, since young fruit can be eaten whole while ripe fruit gives up only its seed. The one real safety question is which kind of almond tree it came from, not which layer you bite into.
The Layers of an Almond Fruit
An almond fruit has three layers, a bit like a dried-out peach. In plums and cherries the outer flesh is soft and juicy, but in almonds it becomes a thick, leathery, grey-green coat with a downy surface. That coat is called the hull.2Wikipedia. Almond Inside it sits a hard, pitted shell that looks like the outside of a peach pit.3Wikipedia. Almond Inside the shell is the seed, made of two large halves covered by a thin brown skin.4PubMed Central. Almonds (Prunus Dulcis Mill. D. A. Webb): A Source of Nutrients and Health-Promoting Compounds
On a real tree, the fuzzy green outside you see in spring is the hull, not the shell. Early in the season a whole almond fruit looks like a small, fuzzy, pale green apricot or unripe peach, so people seeing one for the first time often don’t recognize it. In late summer the hull splits along a seam and starts to dry and brown. Cracking it open reveals the light tan shell, which is what in-shell almonds are sold in. Break the shell and the seed inside is the almond itself.
The shell is the inner part of the fruit wall that hardened as the fruit matured, much like a peach stone, so it belongs to the fruit, not the seed. Market in-shell almonds have already had the hull removed, which is why you rarely see the fuzzy layer on mature ones.
Unlike a peach, whose flesh stays closed and is the part we eat, the almond hull dries and splits open as it ripens.5PubMed Central. Evolutionary Genomics of Peach and Almond Domestication Peaches were grown for their flesh and almonds for their seed.6PubMed Central. Evolutionary Genomics of Peach and Almond Domestication
Eating Green Almonds Whole
Green almonds are simply almonds picked young, before the shell hardens, so the outer layers are still soft enough to eat along with the kernel.7diversivore. Pickled Green Almonds The whole fruit, fuzzy hull included, can be eaten.8PETIT WORLD CITIZEN. Green Almonds The seed inside is pale, skinless, and jelly-like rather than crunchy.9Saveur. How to Cook With Green Almonds—a Fleeting Taste of Spring Whole, they taste crunchy and tart, like an unripe peach or green mango.10Saveur. How to Cook With Green Almonds—a Fleeting Taste of Spring11PETIT WORLD CITIZEN. Green Almonds The inner seed alone tastes milky, fresh, and lightly grassy, with some comparing it to cucumber.12Saveur. How to Cook With Green Almonds—a Fleeting Taste of Spring13Priscilla Martel. Easy Ways with Green Almonds The fuzz softens on the tongue, though some people notice it more than they expected, which is one reason slicing thin helps.
To check whether one is still soft enough, press a knife through it. It should cut easily from fuzz to center. If you hit a hard layer, the shell has formed and only the seed is worth eating. The seed should look translucent or jelly-like, not white and firm.
People eat them raw with salty cured ham and cheese, or shaved over salads.14Priscilla Martel. Easy Ways with Green Almonds They also go into pasta, stews, and pickles, where their sourness cuts rich olive oil.15Priscilla Martel. Easy Ways with Green Almonds A simple way is tossing them in olive oil and sea salt.16PETIT WORLD CITIZEN. Green Almonds
At home, rinse them well and rub off loose fuzz if the texture bothers you. Pickling keeps them beyond the brief spring window.
That window is short, a few weeks in spring before the shell starts to harden. If you have a tree, check the fruit every few days once it reaches full size but is still green and fuzzy, because the change from soft to woody can happen quickly. At markets, look for firm, evenly green fruit with intact fuzz. Shriveled or browning fruit has likely gone past its best.
The Hull and Shell of Ripe Almonds
Mature almond hulls are a by-product fed mainly to dairy cows in California.17PubMed. Feeding high amounts of almond hulls to lactating cows Cows can digest high-fiber material that people cannot, and hulls can make up to a fifth of a cow’s diet while milk stays high.18PubMed. Feeding high amounts of almond hulls to lactating cows Hulls from the sweet Nonpareil variety carry more sugar and less tough fiber than others.19Applied Animal Science. Nutritional composition of almond hulls Some trials, though, found hulls lowered milk output.20PubMed. Influence of feeding supplements of almond hulls and ensiled citrus pulp on the milk production, milk composition, and methane emissions of dairy cows
If you taste a dry ripe hull, you’ll find it leathery and fibrous, hard to chew and swallow. The flavor is faintly sweet and bitter, not unpleasant but not a snack either.
Still, hulls taste mildly bitter with fruity, vanilla-like notes, so companies are exploring them as an ingredient in baked goods, coffee, and snack bars.21Going Zero Waste. Why Almond Hulls Will Be The Next Big Upcycled Food This is processed hull flour, not something to chew from the tree.
The woody shell is too hard to eat. It feels like a small piece of bark and could damage teeth or irritate the throat. It can be burned into a charcoal-like material used to clean metals from water and soil.22Separation and Purification Technology. A novel almond shell biochar modified with FeS and chitosan as adsorbents for mitigation of heavy metals from water and soil23Clean Technologies. Production and Characterization of Biochar from Almond Shells Added in small amounts to salty soils, shells and this charcoal improved soil quality for growing greens.24PubMed. Effects of the amendment with almond shell, bio-waste and almond shell-based biochar on the quality of saline-alkali soils
Sweet Almonds, Bitter Almonds and Cyanide
Wild almonds build up a bitter compound called amygdalin.25PubMed. Mutation of a bHLH transcription factor allowed almond domestication When eaten, the body breaks amygdalin down step by step until it releases cyanide.26PubMed Central. Amygdalin: A Review on Its Characteristics, Antioxidant Potential, Gastrointestinal Microbiota Intervention, Anticancer Therapeutic and Mechanisms, Toxicity, and Encapsulation Cyanide stops cells from using oxygen, which in large amounts harms the brain and heart.27PubMed Central. Potential Toxic Levels of Cyanide in Almonds (Prunus amygdalus), Apricot Kernels (Prunus armeniaca), and Almond Syrup People tamed the almond by choosing trees with sweet seeds, made possible by small genetic changes that switch the bitter compound off.28PubMed. Mutation of a bHLH transcription factor allowed almond domestication29PubMed Central. Detection and distribution of two dominant alleles associated with the sweet kernel phenotype in almond cultivated germplasm
Bitter almonds release about 1,062 mg of cyanide per kilogram, around 40 times more than sweet almonds at about 25 mg.30PubMed Central. Potential Toxic Levels of Cyanide in Almonds (Prunus amygdalus), Apricot Kernels (Prunus armeniaca), and Almond Syrup The bitter taste itself comes from a by-product released with the cyanide, so your tongue can sense the problem before you swallow much.31PubMed Central. Potential Toxic Levels of Cyanide in Almonds (Prunus amygdalus), Apricot Kernels (Prunus armeniaca), and Almond Syrup
The EU caps cyanide in almonds sold to shoppers at 35 mg per kilogram.32Mérieux NutriSciences. New maximum levels of cyanide in food Common sweet varieties averaged only 0.8 to 6 mg per kilogram, far below that limit.33Acta Horticulturae. Which Parts of the Almond Fruit Are Edible? Everyday sweet almonds are safe to eat by the handful.
Trees grown from seed can differ from their parent, so a seed planted from a sweet almond may grow into a tree with bitter nuts. Nurseries propagate named sweet varieties by grafting onto rootstock, which copies the sweet trait reliably. If you inherited a tree or grew one from seed, taste one seed to learn what kind you have, and keep a record for next year.
If an almond from a tree or seedling tastes clearly bitter, spit it out, rinse your mouth, and don’t eat more. Keep bitter seeds away from children, who need less to be harmed.34Mérieux NutriSciences. New maximum levels of cyanide in food
Some mix-ups are common. Apricot kernels look similar to almonds but are a different seed and often contain much more of the bitter compound, so they shouldn’t be eaten like almonds. Almond extract gets its flavor from the by-product released with the cyanide, but it is made so the cyanide is removed; it goes into baking in tiny amounts because its flavor is so strong.
Is the Brown Skin Worth Eating
Almond skins are rich in plant compounds with antioxidant action.35Journal of Food Composition and Analysis. Characterization of polyphenols, lipids and dietary fibre from almond skins (Amygdalus communis L.) They also contain plenty of fiber and some fat, which feed gut bacteria in the large intestine.36Journal of Food Composition and Analysis. Characterization of polyphenols, lipids and dietary fibre from almond skins (Amygdalus communis L.) Blanching to remove the skins washes some of these compounds into the water.37Journal of Food Composition and Analysis. Characterization of polyphenols, lipids and dietary fibre from almond skins (Amygdalus communis L.) Choose skin-on almonds unless a recipe needs blanched ones.
Blanched almonds make pale flour and smooth marzipan, because the brown skin would add color and a slightly rough texture. Skin-on almonds suit snacking, granola, and rustic baking, where color and a little texture are welcome. To blanch at home, drop almonds in boiling water for about a minute, drain them, and pinch each one so the skin slips off.
The skin is fibrous, so some people find large amounts mildly hard on the stomach, with bloating or gas. Chewing thoroughly breaks it down, and starting with a small handful shows you how you react.
Do Raw Almonds Need Soaking or Heat Treatment
Since 2007, US rules have required all raw almonds sold in North America to be treated to kill Salmonella.38University of Delaware. Development and evaluation of a dry heat treatment for inactivation of Salmonella on almonds Methods include steam, roasting, hot-water blanching, or gas treatment.39University of Delaware. Development and evaluation of a dry heat treatment for inactivation of Salmonella on almonds A short steam treatment of about 25 seconds kills the germs without wrinkling or darkening the nut.40PubMed. Evaluation of steam pasteurization in controlling Salmonella serotype Enteritidis on raw almond surfaces So almonds labeled raw in stores are still treated, just not roasted.
Steam-treated almonds look and taste like untreated ones, so you can’t tell by eye or flavor. Roasted almonds are usually brown with a toasted flavor, a sign of higher heat.
Almonds from your own tree have not gone through the pasteurization required for commercial raw almonds. Dry them fully in the shell before storing, because damp nuts can grow mold, a separate risk from germs. Roasting in a home oven is a simple way to heat-treat them, though it changes flavor and color.
Soaking almonds changed their mineral-blocking compound by only about 10% either way.41PubMed. Does ‘activating’ nuts affect nutrient bioavailability? Soaking actually lowered mineral content, especially in chopped nuts.42PubMed. Does ‘activating’ nuts affect nutrient bioavailability? Soak almonds for texture if you like, not for extra nutrients.
Other Edible Products From the Almond
Pressing almonds for oil leaves a solid cake.43PubMed. Almond oil extraction residues as functional ingredients: nutritional composition, biological activities, and polyphenol in vitro bioaccessibility Once the remaining oil is removed, this cake is close to half protein.44Advances in Research. Nutritional Profile and Functional Attributes of Almond Press Cake as a Sustainable Food Source It is very high in fiber and keeps most of its plant compounds.45PubMed. Almond oil extraction residues as functional ingredients: nutritional composition, biological activities, and polyphenol in vitro bioaccessibility It has been made into puffed snacks blended with millet flour.46Letters in Applied NanoBioScience. Development of Functional Snack Food from Almond Press Cake and Pearl Millet Flour
Shoppers meet this as defatted almond flour. Because the fat is gone, it bakes drier than regular almond flour, so recipes often need extra liquid or fat.