Rev Mug — Coffee and tea mugs as a product category | revmug.com
Firing temperature, wall thickness and empty weight decide how a mug heats, cools and survives the dishwasher.
Porcelain fires at 1,200 to 1,400 °C, the hottest of the common ceramics. That range densifies the body until it is barely porous, so porcelain can carry thin walls, low empty weight and a smooth glaze that shrugs off the dishwasher.
Stoneware fires at 1,100 to 1,300 °C. It keeps more thickness and heft, which is why stoneware mugs feel solid and why they slow the slide from brewing temperature — 92 to 96 °C — down to the best drinking window of 60 to 65 °C.
Earthenware fires lowest, at 950 to 1,150 °C, and stays the most porous of the three. It depends on a sound glaze for sealing; chips and crazing matter more here than in high-fired bodies, especially under repeated dishwasher cycles.
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Glass and steel change the questions rather than answer them. Neither carries a ceramic glaze, so the lead and cadmium leaching limits that govern ceramicware — under 0.5 ppm lead and 0.25 ppm cadmium in FDA testing — simply do not apply. Glass shows the fill level; steel, usually double-walled, insulates the longest of the four.
Microwave behaviour splits the list cleanly: ceramics without metallic trim and plain glass reheat without complaint, while steel stays out of the microwave entirely. For the dishwasher, high-fired porcelain and stoneware are the steady performers; earthenware and decorated glass deserve the gentler cycle.
Weight follows firing and wall thickness: thin porcelain is the lightest ceramic per millilitre, thick stoneware the heaviest, and double-wall steel lands between. Pair the material with the right capacity from the size chart, then verify the mug itself with the scale method on the measuring page.
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