An otoshibuta (落し蓋, drop lid) is a lid slightly smaller than the pot diameter that rests directly on the surface of simmering liquid, touching the food. It keeps ingredients submerged, distributes heat evenly, prevents surface evaporation, and allows steam to escape at the rim — avoiding the violent turbulence of a full lid.
Why it works
In Japanese nimono (simmered dishes), the otoshibuta prevents fish and tofu from moving and breaking while keeping them below the liquid surface for even cooking. A full lid traps steam and creates pressure; no lid causes rapid reduction and toughening of proteins.
Materials
- Traditional: paulownia or cypress wood, cut to fit a specific pot
- Adjustable: expanding silicone drop lid fits multiple sizes (the modern standard)
- Improvised: a round of aluminium foil with steam holes punched in it; entirely effective