What is smen, the Moroccan preserved butter?

Smen is the ingredient that divides a dinner table, and I love introducing travellers to it precisely because of that. It is butter — but butter taken somewhere extraordinary. Fresh butter is clarified, heavily salted, sometimes flavoured with herbs like oregano or thyme, then packed into an earthenware jar and left to age, sealed away from the air, for months and often years. What emerges is not bland and creamy; it is pungent, sharp, deeply savoury, with a funk that sits somewhere between aged cheese and something wilder. The first whiff genuinely shocks people.

In traditional households, smen is treasured rather than thrown around. I have been told, more than once, of a jar started in the year a daughter was born and opened at her wedding — the older the smen, the stronger and more prized. It was both a preservation method, a way to keep precious butter-fat through times of scarcity, and a marker of a family's wealth and patience. A pot of well-aged smen in the larder was something to be proud of.

You use it in tiny amounts, and that restraint is the whole secret. A small spoonful melted into the broth of a couscous transforms it — adding a savoury, almost umami depth that fresh butter simply cannot give. It enriches harira, the hearty soup of Ramadan, and rounds out certain tagines and rice dishes. Stirred in at the end, it perfumes the whole pot. Used heavily it overwhelms; used with a knowing hand, it gives that mysterious "what IS that?" richness that home-cooked Moroccan food has and restaurant versions often lack.

For visitors, smen is genuinely an acquired taste, and I never pretend otherwise — its aroma can be confronting if you are expecting butter. But taste a couscous made by a grandmother who has stirred in her own aged smen and you will understand why Moroccans guard it so. If you grow to love it, you can find it in souks and at dairy stalls, sold by weight from large crocks. Start with the smallest amount you can buy, and treat it like a seasoning, not a spread.