Malic acid
Also written malic, malic and citric acids
Quick answer
The rounder, slower sourness of apples and stone fruit — the acid that makes a souring spice taste fruity rather than merely sour.
What it does
Malic acid is sour with a delay and a tail: it builds more slowly than citric acid, sits in the mouth longer, and carries a distinctly fruity, apple-like quality. Where citric reads as a squeeze of lemon, malic reads as a bite of green apple. Its presence is why sumac and barberry taste of fruit as well as of acid, and why a dish soured with either has a body that the same dish soured with lemon juice does not.
How it behaves when cooked
Four properties of the molecule, and what they mean at the stove.
- Volatility
- low
- Fat solubility
- low
- Water solubility
- high
- Heat stability
- high
It behaves as citric acid does in the pan — water-soluble, stable, non-volatile — and the useful difference is in when the sourness registers rather than in how it survives. Because malic acid is slower and longer, a dish soured with a malic-dominant spice can be tasted, judged to need more, and over-soured before the first addition has fully arrived. The practical rule is to add sumac, barberry or anardana and then wait before adjusting, which is not advice anyone gives about lemon juice. Its persistence also means it stands up to being scattered over a finished dish, which is exactly how sumac is used.
Spices that carry it
Recorded on the compound rather than on each spice, so the two cannot disagree.
- AnardanaPrincipal component
- SumacPrincipal component
The reason sumac tastes fruity rather than simply sharp, and why it works scattered over a finished dish.
- AmchoorMajor component
- BarberryMajor component
- Pomegranate molassesContributing component
The second organic acid measured in five bottled pomegranate sours bought in Malatya, at about half the citric acid or less.
- RoselleContributing component
Measured by liquid chromatography in the calyx of three Mexican varieties at 64 to 165 mg per 100 g of dry weight, the second of five acids after succinic acid. Calyces dried in the sun for six days held a third to a half less than freeze-dried ones. The same study had no standard for hibiscus acid and did not measure it, so it cannot say where malic acid stands beside the acid another study found to be the main one.
- VerjuiceContributing component
Named with tartaric acid as one of the two major acids of the juice of unripe grapes. One bottled Iranian verjuice held 202 mg per 100 g, about a sixth of its tartaric acid.
What cooking and processing were measured to do to it
Findings from studies in which this compound was followed through heat, fat, water, drying or storage. Each belongs to its study and its conditions.
Drying · Depends on conditions Malic acid, Citric acid, Anthocyanins, succinic acid, tartaric acid, oxalic acid, colour
Five acids were measured by liquid chromatography in a water extract of the ground calyx. In freeze-dried calyces succinic acid was the largest, at 246 to 325 mg per 100 g of dry weight, then malic at 122 to 153 mg, tartaric at 48 to 60 mg, citric at 7 to 10 mg and oxalic at 1 to 10 mg, about 0.44 to 0.52 g in all. Six days of drying in the sun cut the total by 45 per cent in two varieties and 55 per cent in the third; malic and succinic acid fell most, and citric acid did not fall, standing at 22 to 27 mg. Drying in hot air changed the totals little: they ran from 0.36 to 0.61 g per 100 g across the three temperatures and varieties, and the 70 °C lots were as high as the freeze-dried ones or higher. The acidity of the water extract, by titration, was 37 to 44 per cent lower from sun-dried calyces than from fresh ones. In the two red varieties the sun-dried calyces also gave about 37 per cent less anthocyanin on average, and their extracts were darker.
Conditions: in air · In the sun on concrete; in a tray drier at 50, 60 and 70 °C · Six days in the sun, from nine to five, prolonged by cloud and rain; six to eight hours in the drier · About 10 kg of fresh calyces per lot of three Mexican varieties grown at Acaponeta, Nayarit: Negra Quiviquinta, dark red; UAN-9, light red; UAN-16, white
The authors put the loss in the sun down to its length: calyces lying damp for six days may have had their acids partly fermented by the organisms on them, where hot air at 50 °C or more dries them in hours. It agrees with the handbook’s caution that drying in the sun can lower quality, and with the Indian study in which slow drying in the shade cost hibiscus acid. Of the methods tried, the authors judged hot air at 70 °C to keep the calyx best.
What this does not show: One harvest of three varieties at one site, with sun-drying that took six days because of cloud where two or three are usual; the authors cite another Mexican study that found no loss of acidity after three days in the sun. Hibiscus acid was not measured, so the five acids add up to about half a gram per 100 g where another study found ten grams or more of hibiscus acid alone. The conclusion gives the average loss of acids in the sun as 49.9 per cent, which is not the mean of the three figures in the text.
Measured on the spice
Not to be confused with
Compounds a reader is likely to take for this one, and why they differ.
Citric acid
The pair, and the comparison that makes both records worth having: sharp and brief against round and lingering.
Questions this page answers
- what is malic acid
- what does malic acid do
- which spices contain malic acid