Mostarda di Cremona

Mostarda di Cremona is whole fruit, or large pieces of it, candied in sugar syrup and flavoured with mustard essential oil. What sets the Cremona version apart from every other mostarda is a single decision: the fruit stays whole and stays mixed. One jar holds cherries, figs, pears, apricots, clementines, melon and pumpkin, each still identifiable by shape and colour, floating in syrup that should be clear and glossy.

The heat is not chilli heat, and that is the part that surprises people. Capsaicin burns on the tongue and stays there for minutes. Allyl isothiocyanate, released by mustard essence, is volatile: it rises into the sinuses and disappears in a few seconds. You can eat a very strong mostarda without wrecking the rest of the meal, because each spoonful is an episode that ends.

The name comes from must, not from mustard. Mustum ardens, burning must: medieval cooks preserved fruit in cooked grape must, and ardens described the bite of crushed mustard seed. Sugar replaced the must, the name stayed, and the confusion with French moutarde and English mustard has never gone away.

How much mustard goes in is the producer's signature. Traditional Cremonese houses reach levels that make your eyes water; supermarket lines dose ten times lower, which is why many people assume mostarda is just fruit in syrup.

Sweet first, then a sudden clean burn behind the eyes, then nothing. The sequence takes about six seconds and it is unlike anything else on a table. The fruit itself tastes intensely of what it is (a candied cherry is very much a cherry, concentrated rather than transformed) and the syrup is honeyed and slightly floral.

The pungency is dry and volatile, closer to horseradish or fresh wasabi than to chilli. It clears the sinuses and vanishes without any lingering heat on the palate, which is exactly why it works against fatty boiled meat: it resets the mouth between bites.

If the heat lingers on the tongue rather than rising into the nose, something other than mustard essence is doing the work. If there is no heat at all, you have a jar of candied fruit.

Serve it by the teaspoon, not the spoonful. One or two pieces of fruit and a little syrup per person, set beside the meat and never on top of it. A 380 g jar covers eight to ten people at the table.

With bollito misto (the Po valley trolley of boiled beef cuts, capon, tongue and cotechino, carved at the table) it alternates with salsa verde and grated horseradish rather than replacing them. At Christmas it goes with cotechino and zampone, where the mustard cuts through the fat of the rind.

On a cheese board it is the use that carried mostarda out of Lombardy. It needs cheese strong enough to stand up to it: Grana Padano aged past 24 months, piccante gorgonzola, ripe taleggio, mature pecorino. On anything mild it just reads as sugar.

With roast pork or stuffed poultry, chop it finely and stir it into the pan juices off the heat at the last second. Cooked, the mustard evaporates and you are left with syrup.

One warning: pumpkin tortelli from Mantua take the mantovana version, chopped small. Cremonese whole-fruit mostarda can be made to work if you chop it, but the filling comes out sweeter and less coherent.

The jar is engineered to last: fruit at very high sugar concentration under an essential oil that is itself a preservative. Sealed, it sits in a dark cupboard at room temperature until the date printed on the lid, typically two to three years out. After opening, keep it in the fridge with the lid screwed down and use it over the following months rather than years. Make sure every piece of fruit stays submerged in syrup; anything left proud of the surface dries and hardens at the exposed face.

The mustard is the part with a clock on it. Its pungency sits in a volatile compound that escapes each time the lid comes off, so a jar opened at Christmas and finished in March is measurably milder by the end, with the sugar coming forward. The fruit itself darkens, absorbs more syrup and slowly loses its edges. Crystals in the syrup or a stiffening around the rim are sugar leaving solution; standing the jar in warm water dissolves them again. Freezing is not the answer, since candied fruit thaws limp. The lid date and the producer settle anything else.

A Cremona jar looks like a jewel box: whole candied fruits kept intact and separate, each one candied on its own before assembly, so you can pick out a cherry, a fig, a slice of pear, an apricot, a mandarin, a piece of melon rind, and each keeps its own colour. The syrup around them is clear, thick and glassy, not cloudy and not a puree. The fruit should be translucent right through and still firm under a fork, not slumped or grainy.

Two confusions abroad. The first is with candied fruit: check the ingredient list for senape or essential oil of mustard, and if it is absent you have glacé fruit in syrup. The second is with the Mantovana and Vicentina styles, which are chunky or pasted and legitimately different products; Cremona means whole fruit. Anglophone shops sometimes shelve it as mustard fruits or Italian chutney, which describes neither the texture nor the heat. Sperlari, Fieschi and Vergani are the Cremonese names on export shelves, at $14 to $24 for a 380 gram jar.

In Italy, an artisan 380 g jar runs 7 to 11 euro, which is 18 to 30 euro a kilo; supermarket lines sit at 12 to 16 euro a kilo and are notably milder. Christmas gift jars with the fruit arranged in visible layers reach 35 to 45 euro a kilo: presentation you are paying for, though with mostarda the look of the whole fruit genuinely is the product.

In the US, Italian importers and specialist grocers carry it at roughly 14 to 24 dollars a pound, usually in 200 to 380 g jars. In the UK, Italian delicatessens and cheese shops stock it at 25 to 40 pounds a kilo: cheesemongers are often the better bet, since mostarda has become a standard board accompaniment.

Read the label for two things. The ingredient list should be fruit, sugar or glucose syrup, and mustard essential oil; colourings such as E102 or E122 are there to brighten faded candied fruit. And check the fruit is whole and distinct through the glass: collapsed, indistinct pieces mean the candying was rushed.

If you can smell nothing when the jar opens, the mustard was dosed not to trouble anyone.

Cremona is small and walkable: the Piazza del Comune under the Torrazzo, the tallest brick bell tower in Europe, and the Museo del Violino, which holds instruments by Stradivari, Amati and Guarneri. The mostarda is sold in the historic confectioners in the centre, in the same windows as the torrone: the two products have shared a trade in this city since the nineteenth century.

Go in the third week of November, when the Festa del Torrone fills the old centre with stalls, demonstrations and tastings. Mostarda is everywhere and you can try before you buy.

To eat it properly you want a bollito trattoria, and the geography is the Bassa: Cremona, Casalmaggiore, Soresina and the villages between the Po and the Oglio. The trolley runs from about October to March, because boiled meat is winter food.

Fifty kilometres east, Mantua lets you make the comparison directly: campanina apple mostarda and pumpkin tortelli, which is the fastest way to understand why the two are not the same product.