The taste of Dutch licorice comes mainly from two compounds. Glycyrrhizin, from the root of the licorice plant, makes it sweet; in salty drop, ammonium chloride (salmiak, E 510) adds the sharp, salty-sour bite. This entry explains what each compound is, how it works on the tongue and in the body, and how it is regulated.
Glycyrrhizin: what it is
Glycyrrhizin (glycyrrhizic acid) is a triterpenoid saponin found in the root of Glycyrrhiza glabra, the licorice plant (Dutch zoethout). Its molecular formula is C42H62O16, with a molar mass of about 823 g/mol. Chemically it consists of a steroid-like aglycone, 18β-glycyrrhetinic acid, bound to two glucuronic acid units.
Glycyrrhizin is usually described as 30 to 50 times sweeter than sucrose. Its sweetness builds more slowly than that of sugar and lingers, which is why licorice has its characteristic long, sweet aftertaste and why the extract is not used as a general sweetener. Its content in the root varies with species, origin and growing conditions. Commercial licorice root comes mainly from western and central Asia and the Mediterranean, including Turkey, Iran, Uzbekistan, Afghanistan, Italy and Spain; Dutch factories buy in extract rather than growing the plant. As a food additive it has the code E 958.
Glycyrrhizin in the body
In the gut, bacteria convert glycyrrhizin to glycyrrhetinic acid, which is absorbed. Glycyrrhetinic acid inhibits the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2). In the kidney this enzyme normally inactivates cortisol so that it cannot act on mineralocorticoid receptors. When the enzyme is blocked, cortisol has aldosterone-like effects: the body retains sodium and water and loses potassium. Clinically this is called pseudohyperaldosteronism or apparent mineralocorticoid excess.
With heavy, regular intake the result can be high blood pressure, low potassium, fluid retention and muscle weakness, and in severe cases heart-rhythm disturbances. The effects reverse after licorice is stopped, though this can take weeks. The elimination half-life of glycyrrhetinic acid is several hours, so daily consumption keeps levels elevated.
How much glycyrrhizin is safe?
The EU Scientific Committee on Food concluded in 2003 that regular intake of glycyrrhizic acid should not exceed 100 mg per day. A dose-response study (Sigurjónsdóttir et al., 2001) found that blood pressure rose with daily licorice intake in a roughly linear way, even at moderate doses. The glycyrrhizin content of candy varies widely between products, and many bags do not state it, so it is not possible to give a reliable "number of pieces" limit. EU labelling rules flag products with high levels; these are explained, with practical advice, in licorice and health.
Ammonium chloride: what it is
Ammonium chloride (NH4Cl, molar mass 53.5 g/mol), known in Dutch and the Nordic languages as salmiak, is a simple salt that dissolves readily in water into ammonium and chloride ions. Its solution is mildly acidic (around pH 5 to 5.5 depending on concentration), and dissolving it absorbs heat, so it can feel slightly cool on the tongue. It is an authorised EU food additive, E 510.
In confectionery it is mixed into the licorice paste, dusted on the surface, or both. Mixed in, it releases gradually as the sweet dissolves; as a coating it gives an immediate sharp hit. Dutch drop that contains it is sold as zoute drop or, at higher doses, dubbelzout.
Why does salmiak taste the way it does?
Salmiak does not taste like table salt. The chloride ion contributes some saltiness, but the distinctive sharpness comes from the ammonium ion. Research published in Nature Communications in 2023 by Emily Liman's group at the University of Southern California showed that ammonium chloride activates OTOP1, a proton channel in the taste cells that detect sour taste; in mice lacking OTOP1, taste responses to ammonium chloride were largely lost. That helps explain why salmiak reads as a mixture of salty, sour and slightly bitter, and why people who did not grow up with it often find it startling. Familiarity matters: in the Netherlands and the Nordic countries the taste is learned in childhood.
Why ammonium chloride is used in the Netherlands
Ammonium chloride was long sold by pharmacists as an expectorant for coughs, and salmiak pastilles still occupy a borderline between sweet and remedy. Licorice itself started as a cough remedy in the Low Countries (see the history of drop), so combining the two was a natural step. The flavour then became a taste preference in its own right in the Netherlands, northern Germany and the Nordic countries.
How much ammonium chloride is in drop?
EU law caps ammonium chloride in most foods but sets no specific maximum for licorice confectionery. Salty licorice can contain up to about 8%: English Wikipedia reports that popular Swedish salty licorice averages around 7%, and that at up to 7.99% salmiak pastilles have been treated as a traditional cough remedy in some countries. Widely repeated "Dutch legal thresholds" of 2%, 4.49% and 7.99% for zout, dubbelzout and stronger drop are not Dutch law; they appear to derive from former German rules. Most Dutch packaging does not state the percentage, so "dubbelzout" is a maker's description rather than a regulated grade.
What is the pH of licorice?
There is no single answer. A solution of ammonium chloride is mildly acidic, around pH 5–5.5, and the other ingredients of drop (sugars, starch, extract) are roughly neutral to slightly acidic. Sweet drop without salmiak has no particular acidity of note. Published measurements for specific Dutch products are scarce, so we do not give figures for individual brands.