No, the almond nut isn’t a nut. I’m not sure if that should blow your mind. After all, pistachios, cashews, macadamias, and peanuts aren’t nuts. Neither are pine nuts. Does it really matter? No. Tomatoes are fruits but we treat them like vegetables in a culinary sense. Almonds and its non-nut compatriots are similar. But, if an almond isn’t a nut, what is it?
First, before you’re whole world starts crumbling and you wonder if up is really down, some nuts are actually nuts. Walnuts, chestnuts, acorns, for example, are true nuts. Pecans, although they seem somewhat similar to walnuts, are not actually nuts, though. Brazil nuts also are not nuts. What a mess!
What is a Nut?
To be clear, nuts aren’t all that different from nut-like foods like almonds. They are fruits. Botanically, a nut is one-seeded, dry fruit with a hard shell or ‘pericarp.’ Only a relative handful of the foods we consider nuts actually meet this definition. In addition to walnuts, chestnuts, and acorns, hazelnuts and filberts also are true nuts. Most of the other true nuts are either not well-known in the west or not as commercially important. A few examples are candlenuts, kola nuts (used to flavor the first colas), and palm nuts.
Almonds are Drupes
An almond is a drupe fruit. A drupe fruit is a fruit with an outer fleshy part that surrounds an inner shell or ‘pit’ with a seed inside. Familiar examples of drupe fruits, sometimes called stone fruits, are peaches, nectarines, prunes, apricots, cherries, and mangoes. An olive is also a drupe or stone fruit and so is a coconut.
Upon learning this, you’ve probably had an aha moment. The pits or seeds of these fruits are not edible, although we can extract and use the oil from some of them.
Some drupes, like almonds, (Prunus dulcis or Prunus amygdalus) have edible inner seeds. They come from the same genus as the peach, Prunus. However, unlike the fleshy exocarp of a peach or plum, the almond fruit has a thick, leathery outer covering, or hull, covered with a fine downy growth and having a greyish-green color.
But, it can be hard to tell the difference between these non-nut nuts and true nuts. After all, true nuts have a protective husk over the inner shell.
Well, one way to tell is that in a true nut, the seed, or flesh of the nut will be fused to the shell. If it is not fused, it’s not a nut. For example, look at these macadamias. Not nuts.
The outer part of the almond is not edible and the inner part that surrounds the seed, the endocarp or shell, must be removed. The ‘nut’ we call the almond is this inner seed. When an almond fruit matures, the hull splits and separates from the shell and the fruit falls from the tree. Not often, but once in a while, two seeds appear inside the inner shell.
The inner seed or ‘nut’ of an almond, the part that we eat, has a thin brown skin covering it. Blanched almonds are almonds that have been treated with hot water to remove this skin.
Pistachios Aren’t Nuts Either – Another Drupe!
Pistachios are in the same family as cashews (Anacardiaceae), so, yes, cashews aren’t true nuts, either. Pistachio fruits have a fleshy outer hull as almonds do. These ripen to a reddish-yellow color similar to the color of some autumn leaves. Cultivated varieties split open when mature.
The cashew drupe can be confusing as it appears that the ‘edible nut’ portion grows underneath the fruit, which is sometimes called a cashew apple. This is not exactly true, though. What appears to be a pretty pear-shaped fruit is actually a false fruit, accessory fruit, or pseudocarp that develops from the pedicle and the receptacle of the cashew flower. The true fruit grows at the end of this structure. It is a kidney-shaped drupe that actually develops before the cashew apple. The cashew apple itself, which is more like a fleshy stem, is also eaten, used in cooking, preserved in jams and chutneys, and used to make an alcoholic liquor.
The outer fleshy part of the cashew seed has a double shell that is quite irritating to the skin, similar to poison ivy. This is why you’ll never find them sold in the shells.