Thermosteel CeramiSteel Coffee Ceramic Travel Mug (12 oz), Insulated Stainless Steel, Blue Review (2026)

What makes CeramiSteel different

CeramiSteel is Thermosteel's name for a ceramic coating applied over the rim and interior of an otherwise standard insulated stainless steel tumbler. The idea is to combine the durability and insulation of steel with a drinking surface that does not carry the faint metallic taste some people notice with bare stainless mugs, especially with acidic drinks like coffee. Because the coating covers the rim as well as the inside, your mouth does not make contact with raw metal at all when sipping. This matters most to people who are sensitive to that metallic edge or who have compared steel and ceramic mugs side by side and prefer the taste from a ceramic-lined cup.

Capacity and everyday fit

At 12oz, this mug holds a standard large coffee shop serving, and its shape is sized to fit most car cup holders, which is a common complaint with larger 16 to 20oz travel tumblers that can be too wide or tall for many vehicles. That makes this a reasonable choice for a daily commute mug rather than an all-day sipper, since it holds less than the bigger tumblers on the market. Anyone who wants to bring a large batch of coffee or wants to refill less often during a long day should look at a bigger capacity mug instead, since 12oz is on the smaller end of the insulated travel mug category.

Insulation and construction

The mug uses double-wall vacuum insulated stainless steel construction, the same basic approach used across most quality travel tumblers, which keeps hot drinks hot and cold drinks cold for an extended period compared to a single-wall cup. The stainless steel body underneath the ceramic coating provides the durability of a metal mug, meaning it should hold up to daily use, drops, and the occasional knock better than a plain ceramic mug would. Food-grade stainless steel is the standard material for this category, and it is dishwasher safe according to the product listing, which makes day-to-day cleaning straightforward without needing hand washing or special care.

Caring for the ceramic coating

Because the ceramic layer sits on top of the steel rather than being a separate glazed piece, it can chip if the mug is dropped hard, knocked against a hard countertop edge, or scrubbed aggressively with an abrasive pad. This is a known tradeoff with any ceramic-coated drinkware, not something unique to this mug, and it means a slightly more careful hand than you would use with an uncoated steel tumbler. Sticking to normal dishwasher cycles or gentle hand washing, and avoiding metal scrubbers, is the simplest way to keep the coating intact over the mug's lifespan. Treated reasonably, it should hold up to regular daily use without issue.

Who this mug suits

This is a good option for someone who already knows they prefer the taste of a ceramic-lined cup over bare steel and wants that in a compact, cup-holder-friendly size for commuting. It is a weaker fit for anyone who wants a larger all-day capacity or who is rough on their travel mugs and would rather not worry about chipping a coating. As with any insulated tumbler, actual heat retention time was not something independently confirmed here, so treat general double-wall insulation performance as typical for the category rather than a specific tested number for this exact mug.

Frequently asked questions