Two grades of steel, two walls

OREA spent three years on this cup, and most of that work went into the material and the fit. The inner wall is SUS316 stainless steel, chosen over the more common SUS304 because it holds up better against acidity and corrosion and does not carry a metallic taste into the drink. That inner surface is electropolished, which smooths out microscopic roughness and makes it easier to keep clean over time. The outer wall is SUS304, the same grade used in insulated bottles. Between the two sits an air pocket, larger than the one in OREA’s steel O1 brewer, which keeps the coffee warm for noticeably longer than a porcelain cup of the same size and leaves the outside cool enough to hold in a bare palm.

What 150 ml is good for

The 150 ml capacity is deliberately the UK flat white size, so a double shot plus textured milk fills it without crowding the rim. It also works for cortados, hot or iced espresso, small matcha drinks, and a modest pour-over. If you are texturing milk at home with something like the Subminimal NanoFoamer, this is a sensible target volume to pour into. One less obvious use: at 150 ml the cup suits micro-cupping with 7 to 8 g of coffee, which is handy when you want to taste through a rare or expensive lot without committing a full SCA bowl.

Steel versus porcelain

Steel and porcelain behave differently in the hand and in the cupboard. A porcelain cup such as one from the Loveramics Egg Series has thermal mass in the wall itself, so it wants preheating and it will chip if it meets a tiled floor. The STAC has almost no thermal mass, insulates instead, and survives being dropped. The trade-off is the drinking edge: a steel rim feels different against the lip than glazed porcelain, and some people prefer one over the other. If you run a café bar, the durability and stacking argument is fairly one-sided.

Specifications

What’s in the box

• 2 × OREA STAC steel cups