Sour candy: a field guide to every kind, and what makes each one sour

Sour candy is candy with enough food acid in it to make you wince. Where the acid sits decides how long the sour lasts, and the first word on the label says what the acid is sitting on, which is syrup far more often than it is a strawberry. Start with the acids.

On this page

• What makes candy sour
• The kinds of sour candy
• Sour on the outside vs sour all the way through
• How to read a sour candy label
• Sour candy made from fruit

What makes candy sour

Sour is what the tongue does with acid. Sugar is what makes it candy. The ratio between the two is most of what you taste. Tip it toward acid and the candy bites back. Too far the other way and it is fruit punch.

Four food acids do nearly all of the work.

• Citric acid. The lemon acid. It hits fast and is gone in a few seconds. The FDA's listing calls it a naturally occurring constituent of plant tissue, recovered from lemon or pineapple juice or made by fermentation. It is the first acid on almost every sour candy label.
• Malic acid. Green apple. It arrives a beat after citric and stays, rounder and longer. When a label wants the sour to last, malic is doing it. It is also the one of the four with a numbered ceiling. The FDA caps malic acid at 6.9 percent of a hard candy and 3 percent of a soft candy, and keeps it out of baby food.
• Tartaric acid. The grape acid. Drier at the edges than citric, and rarer on labels.
• Fumaric acid. The strongest sour per gram of the four. It also does not pull water out of the air, which is why it goes into sour powders and dusted candies that have to stay dry in the bag.

A few labels add ascorbic acid, which is vitamin C and a little sour, or lactic acid, which is soft and milky. Neither carries a sour candy on its own. Pure citric acid on the tongue is a dare. The sugar is what makes you reach for a second one.

The kinds of sour candy

Seven kinds of sour candy are worth telling apart. What differs is what the acid sits on, and whether it is on the surface or inside the thing itself.

Hard sour candy

Sugar and syrup, boiled until the water is nearly gone, then cooled into glass. The sour comes two ways. Dusted on the outside, it is a sharp first second and then plain candy. Cooked into the boil, it lasts as long as the candy does, because every layer you dissolve is as sour as the last. The ones with a warning on the wrapper do both: acid powder over a center that was already acidic. A hard candy also sits in the mouth longer than any other kind. That matters for the teeth question at the end.

Sour gummies

A gummy is a gel. The gel is gelatin, which is animal collagen, or pectin, which comes from fruit, or a modified starch. On its own a gummy is sweet. The sour is sanded on. The gummy is rolled in sugar and acid, citric and malic as a rule, and the crystals cling to the surface. So a sour gummy is sour for about four seconds and then tastes like whatever it was underneath, and the bottom of the bag holds the sour that let go. Gelatin and syrup make a candy that is candy all the way down. Fruit puree with pectin is the version that began as fruit.

Sour belts and straws

Belts are extruded strips of sugar, starch and syrup, sanded on both faces with acid and sugar, then cut into lengths. A straw is the same dough rolled into a tube. A belt hits harder than a gummy of the same weight, and the reason is geometry. A flat strip has more surface per gram than a cube, and the sour lives on the surface. Bite a belt in half and lick the cut edge. Nothing.

Sour powders

The acid is the candy, cut with dextrose or sugar so you can stand it. Powders come loose in packets, in paper straws, and as a dip for a candy stick. With nothing to carry it, a sour powder is sour all the way through by definition and gone almost at once, because powder dissolves faster than anything else on this page. The acid is citric, often with malic, and sometimes fumaric, which keeps the powder from clumping.

Sour sprays and liquids

Acid dissolved in water and syrup, with a preservative so it keeps. The first ingredient on most of them is water. There is nothing to chew, so the sour is instant and leaves with the swallow. Sour liquid also turns up as the filling in some gummies and hard candies, doing the inside half of an outside-and-inside candy.

Freeze-dried candy

Freeze-dried candy is a texture category. The sour has nothing to do with it. Gummies, taffy and chewy candies are freeze-dried, the water leaves under vacuum, and the candy puffs into a crisp shell several times its old size. The sour is whatever the candy had going in, and a sanded coat often falls off along the way, so a freeze-dried sour gummy is usually less sour than the gummy it was. What changes is the crunch. The ingredient list comes out the way it went in, syrup, gelatin, dye and all.

Fruit-based sour candy

The last kind starts with a fruit. Fruit leather with acid added, dehydrated fruit tossed in sour sugar, candied citrus peel and sour freeze-dried fruit all belong here. The fruit arrives with acid of its own. A grape carries tartaric and malic acid before anyone opens a bag of citric, and a strawberry sits around pH 3 to 3.9 by itself. We ranked twelve fruits by their acid, a number for each, if you want to know which fruit does the most work before any sour is added.

Sour on the outside vs sour all the way through

Most sour candy is sour on the outside. The acid is a coat, crystals of sugar and citric or malic acid sanded onto a gummy, a belt or a hard shell. The coat dissolves in the first few seconds and the candy underneath takes over. That is on purpose. A sanded gummy is built to open sharp and close sweet. Lick one, wait, lick it again. If the second taste is plain, the sour was on the outside. The sand at the bottom of the bag is the rest of the evidence.

Sour all the way through means the acid is in the body of the candy. There are three ways to get there. In a hard candy the acid is cooked into the boil, so every layer is sour. In a powder the acid is the body. In a fruit the acid is dissolved in the fruit's own juice, and more can be infused into it, so the sour is in the flesh rather than on it. A sour candy that is sour all the way through lasts as long as the piece does. There is no plain center to arrive at.

Some candy is both. A hard candy with an acid coat over acidic glass is both. So is REFRESH'D sour freeze-dried fruit. The fruit is Infuz'd with sour all the way through, and the coat on the outside is the encore. What you taste is time. A coat is over in seconds. A through-and-through sour runs the length of the piece, and the sweetness of the fruit shows up beside it instead of after it.

How to read a sour candy label

An ingredient list answers four questions, and the panel a fifth.

What it is made of. Ingredients are listed by weight, heaviest first. That is an FDA rule, so the first word is the candy. Corn syrup or sugar first, and the candy is syrup with things added. A fruit first, and the candy is fruit with things added. Everything after the first word is detail.

How sour it is, and which sour. Find the acids: citric, malic, tartaric, fumaric. The order says which one leads. The position says roughly how much. An acid listed before the flavor is a real dose. An acid listed after "natural flavor" is a pinch. Citric and malic together means a fast front and a long finish.

What holds it together. Gelatin means an animal collagen gel and a candy that is candy through and through. Pectin or fruit puree means the gel came from fruit. Modified food starch is the neutral one and turns up in both. Syrup, gelatin, Red Dye #40. Those three tell you a sour candy has nothing to do with fruit beyond the picture on the bag, and they arrive together.

Where the color came from. Under the FDA's rules, a certified color has to be named on the label, as FD&C Red No. 40 or the short form, Red 40. The certified list is short. Red 40 is the one on most sour candy, approved for confections, which is why it is on so many of the red, pink or purple ones. A bright candy with no fruit and no named dye on the list got its color from an exempt color, beet or beta-carotene, which the label may group as "color added." A candy whose color is the fruit lists no color at all.

The five-second version, in order:

• First ingredient. Syrup, sugar, or a fruit.
• Acids. Which ones, and how far up the list they sit.
• Gel. Gelatin, pectin, or starch.
• Color. A named dye, "color added," or nothing.
• Sugar. On the Nutrition Facts panel as total and added sugars. Every kind of sour candy carries it, the fruit kind included.

Sour candy made from fruit

Fruit was sour before candy was. A cranberry sits at a pH of about 2.3 to 2.5, a lime near 2, a strawberry around 3 to 3.9, and the acid in each is the same citric, malic and tartaric acid that candy makers buy by the bag. So fruit-based sour candy gets a head start. Part of the sour was in the fruit. The label adds the rest.

Fruit leather is puree cooked down and sheeted, with citric acid added for brightness; it is soft and it sticks to your teeth. Dehydrated fruit tossed in sour sugar is chewy, and also sticky. Sour freeze-dried fruit is the third. The fruit is frozen, the water leaves gently, and what remains is the fruit's solids with all of its acid still in them, at a fraction of the weight. That is why freeze-dried fruit reads sharper than fresh before anything is added.

That is what REFRESH'D makes. Sour freeze-dried fruit, five fruits and a variety pack: strawberries, blueberries, grapes, mangos and pineapples. Read the bag by the rules above and it goes like this. First ingredient, the fruit. Then, in square brackets the bag labels Sour Coating: sugar, maltose, glucose, apple juice concentrate, modified food starch, citric acid, malic acid, natural flavor. No gelatin. No named dye, because the color is the fruit's. The sugar is on the Nutrition Facts panel. About 60 calories per 12 to 30 pieces, flavor dependent, and the count for each fruit is printed on its bag. Blueberries is the long one: 30.

It is still candy. It carries sugar, and the panel says so. The first word on the label is a fruit, and the acids do the same job they do on every other bag in the aisle, on a strawberry instead of on syrup.