Intact glazed ceramic is one of the most hygienic food surfaces available, and damage changes that.
Why Intact Glaze Is Good
A fired glaze is a layer of glass: non-porous, smooth and with nowhere for residue to lodge.
It does not absorb, does not hold odours, and washes completely at ordinary temperatures.
That is why ceramic and glass are preferred over worn plastic for anything acidic or strongly coloured.
Where It Stops Being True
- Crazing, where food and liquid enter fine cracks
- Chips on food surfaces, exposing porous clay
- Deep scratches through the glaze
- Unglazed decorative areas, which absorb
- Repaired pieces, where adhesive is neither food safe nor washable
Advice to avoid sudden temperature changes, of the kind given at https://famiware.net/, is largely about preventing crazing, which is the point at which a hygienic surface stops being one.
Cutting Boards, Not Plates
A practical note. Ceramic is hard, which is why it marks knives rather than the reverse, and why cutting on a plate blunts cutlery quickly.
It also means a plate is not a cutting board and does not need to be treated as one for cross-contamination purposes, provided raw and cooked food use separate items.
Raw Meat
A plate that held raw meat needs washing before anything cooked touches it, which is obvious and routinely forgotten at barbecues.
Two plates, one for raw and one for cooked, is the standard advice and it is worth following.
Dishwasher Versus Hand Washing
A dishwasher washes hotter than hands tolerate, which is generally better for hygiene provided the machine is not overloaded.
Tea Towels
A towel used repeatedly transfers between items and hands. Change them frequently and wash hot.
Retire Damaged Pieces
Which is the whole practical conclusion.
Check Rims Twice a Year
Ten minutes for a set.
Separate Plates at a Barbecue
One for raw and one for cooked, which is where this most often goes wrong.
Acidic Food Suits Ceramic
Better than worn plastic, which absorbs and stains.
Wash Before Storing
Residue left on a plate in a cupboard is residue nobody sees.
Wash Tea Towels Hot
A towel used for hands and dishes transfers between them all week.
Retire Crazed Pieces
Which is the point at which a hygienic surface stops being one.