Ceramic Coffee Mugs: Why No Two Reactive Glaze Mugs Are the Same, and How to Choose Yours

Everyone has one. The mug that is somehow the right weight, holds the right amount and sits properly in the hand. It is rarely the newest one you own, and it is never the one you would have picked out of a lineup on looks alone.

This guide is about finding that mug on purpose: what reactive glaze actually is, why the mug that arrives at your door will not be identical to the one in the photograph, and how to work out which size suits the way you drink your coffee or tea.

What reactive glaze actually is

A glaze is a thin layer of glass fused to the surface of a ceramic piece in the kiln. Most glazes are designed to come out as one flat, even colour every time.

A reactive glaze is designed to do the opposite. It contains minerals that react with each other and with the heat as the piece is fired. Where the glaze runs thick, it pools and darkens. Where it runs thin, over a rim or the edge of a handle, it breaks to a lighter colour. Small speckles, flecks and shifts in tone appear wherever the chemistry decides.

The result is depth. A reactive glaze mug looks like it has a story, even on the day it is unwrapped.

Why no two mugs ever match

Because the glaze reacts differently every time it is fired, no two pieces come out quite alike. Each of our mugs is glazed by hand, and the thickness of the glaze and the way it moves as it melts all leave their mark.

So when you order a pair, you get two mugs that clearly belong together but are not identical. One might have a deeper pool of colour at the base, the other a lighter break around the rim. That is not a fault. It is the reason to choose reactive glaze in the first place.

If you like everything to match exactly, a reactive glaze mug is probably not for you. If you like being able to tell your mug from everyone else’s at a glance, it very much is.

Which size do you need?

Mug sizes are given in millilitres, which is not how most of us think about a cup of tea. As a rough guide, a standard British mug holds somewhere around 300 to 350ml. Everything in our range is larger than that, so it is worth matching the size to the drink.

Around 430 to 460ml: an everyday large mug. A proper cup of tea with room for milk, or a long coffee that does not need topping up halfway through. The Fjord, Nova, Echo and speckled Lotus mugs sit here.

Around 500 to 600ml: the generous one. For people who make one coffee in the morning and want it to last. The striped Luna, the Ignea, the Titan and the Vega mugs are in this band, along with the new Vega speckle.

720ml: the very big one. The Aurelia holds more than twice a standard mug. Lattes, whisked matcha, soup on a cold lunchtime, or tea for someone who refuses to get up and make a second cup.

For loose leaf tea: the infuser mug. The new Aska is a large reactive glaze mug with a lid and a removable stainless steel infuser, so you can brew straight into the cup. It comes in four glazes: navy, sage green, sea green and ocean teal.

If you are buying for someone else and are not sure, the middle band is the safe choice. It is big enough to feel generous without being unwieldy.

Picking a mug you will actually reach for

Size is only part of it. A few other things decide whether a mug becomes the favourite or lives at the back of the cupboard.

The handle. If you drink with your fingers through the handle, check there is room. If you tend to wrap both hands around the mug, the shape of the body matters more than the handle.

The colour you will see every morning. Blues and greens feel calm and cool. Pinks and natural tones feel warmer. Striped and speckled glazes hide the odd tea ring better than pale plain ones.

What it sits next to. If you already have plates or bowls you love, pick a mug that sits comfortably beside them. A blue mug next to Havn tableware, or a green one next to Rivah, makes a breakfast table look planned without any effort at all.

Looking after ceramic mugs

Our mug pairs are listed as dishwasher and microwave safe on their product pages, so they are made for daily use rather than for the shelf. For the Aska infuser mug, check its own product page for care, and take the steel infuser out before it goes anywhere near a microwave. A few small habits keep the glaze looking its best:

• Load them so they are not knocking against each other in the dishwasher
• Avoid scouring pads and abrasive powders on the glazed surface
• Give a mug a moment after the microwave before you grab it, as the handle can warm up too

That is genuinely all there is to it.

Why we sell them in pairs

Apart from the Aska infuser mug, every mug in the range comes as a set of two. Partly because coffee is often made for two, and partly because a pair makes an easy present: one for them, one for whoever they share the kitchen with. Because each mug is glazed by hand, the pair will be a close match rather than a perfect one, which is rather the point.

If you are already thinking about Christmas, our Christmas gifts page brings the mugs together with teapots and tableware. And if you are more of a teapot person, our guide to choosing a teapot covers that side of the kettle.

Browse the full mug collection and find the one you will reach for first. Standard UK delivery is free on every order.