Kolkata cooking involves a lot of frying, and the air here stays humid almost all year. That combination means oil vapour never fully hardens — it stays soft, keeps collecting airborne dust, and transfers onto every surface a cloth touches next. A kitchen that felt clean on Sunday is tacky again by midweek, and it is not a cleaning failure.
Older kitchens here add another layer. Many were built before chimneys were common, with high ceilings, a single small window and no extraction at all, so decades of vapour has gone straight onto the walls and ceiling above the hob.