We recommend using S304 (18/8 in food world) or SS316/SS316L (“marine grade/medical grade”).
Stainless Steel 3xx series (18/8, 18/10, etc.) is commonly found in food and hospital settings for their low corrosion, chemical inertness, and general biocompatibility*.
*low risk of incompatibility
SS3xx can be coated with materials to minimize double-layer effects.