Are stoneware mugs microwave safe? | All you need to know

Stoneware mugs that are in good condition are microwave safe. Check the base of the mug and should indicate ‘microwave safe’ on the bottom. Use stoneware mugs to reheat soup or to warm up hot chocolate. Make sure that the mug does not have any cracks or chips. Cheaper stoneware mugs can have chemical additives in the glaze that may leech out when microwaved.

The stoneware that I have bought from Country Road has a night matte finish and has lasted for at least 5 years with minimal scratches. They are microwave safe which works well when I need to reheat a cup of tea when I’ve forgotten about it.

My 2 favorite stoneware mugs are the blue ones.

This article will explore all you need to know about microwaving stoneware mugs. This includes how to avoid it breaking and how to test if it is microwave safe if you are not sure.

Tips for putting stoneware mugs in the microwave

Here are my top tips for putting stoneware mugs in the microwave safely without making a mess.

1. Check the bottom to see if it is marked microwave safe

The easiest way to find out if your stoneware mug is microwave safe is to check the bottom. Most microwave safe stoneware mugs will be marked with microwave safe.

If you regularly put your stoneware in the dishwasher it will eventually wash off. My more expensive stone mugs have kept their markings but the cheaper ones have washed off within a few months.

Check the bottom of stoneware mugs to see if they are marked microwave safe.

2. Test stoneware mugs if you are not sure

If you are not sure if your stoneware mug has been marked as microwave safe then it is time to test the mug.  Sometimes we have mugs sitting in our cupboard for years without using them. Before you throw it in the microwave, use this method to see if it is microwave safe.

Fill the stoneware mugs half full with water and put it in the microwave for 30 seconds. Take it out of the microwave carefully and test to see if the mug is hot.

If the mug is hotter than the water then you should not use the cup in the microwave.

If the water in the mug is hotter than the stoneware then it should be fine. Check the rest of the criteria below before you go ahead and microwave your mug.

2. Avoid mugs with metallic rims or markings

Avoid microwaving stoneware mugs that have a metallic rim or patterns. The metal in the ring could spark and damage your microwave or cause a fire. Check the stoneware mugs and make sure there is no visible metal before microwaving.

3. Find out where it comes from

Some cheaper stoneware mugs made could contain additives in the glaze that can leach out when microwaved. We are often unaware of the process and materials in cups and glaze. Many countries have low regulations when come to the ingredients that are used in some of these mugs.

Check where the stoneware mugs is manufactured and if you have any concerns then avoid using it in the microwave

The writing on the bottom of this cheaper stoneware mug has washed off in the dishwasher after a few months.

3. Check for chips or cracks

Check the stoneware mugs for chips or cracks before putting it in the microwave. Marks or damage could show that the stoneware mugs has been dropped or suffered from thermal shock. This means that it could break the next time it is heated up.

How to test if stoneware mugs are microwave safe

It is important to test any stoneware mugs before using them in the microwave. To do this simply follow these steps below.

1. Fill the mug half way up with room temperature water

2. Place it in the microwave and cook on high for 30 seconds

3. Carefully remove the stoneware mug and test to see if it has heated up more than the water. If the mug is cool and the water has started to warm then the mug should be fine in the microwave.

Make sure the mug doesn’t have any metallic designs and is not cracked or chipped. If so, then you can heat up your soup or hot chocolate!

Stoneware can scratch over time, check out my previous article here for more on preventing scratches: Does Stoneware Scratch Easily? | How to Prevent and Remove Scratches

Putting handmade stoneware mugs in the microwave

Handmade stoneware mugs can be used in the microwave. Check that it does not have a metallic rim or any metallic patterns. Check that it is marked “Microwave safe” on the bottom of the mug. If it is not marked as microwave safe then test it yourself first with the water method.

Check the stoneware mugs for cracks or chips before microwaving any food or drinks.

Never microwave an empty mug, the rapid change in heat could cause it to break.

Store the stoneware mugs carefully to avoid it being hit against other cups and weakening the structure.

Putting cheap stoneware mugs in the microwave

Avoid putting cheap stoneware mugs in the microwave if you don’t know where it came from or where it is made. There could be chemicals in the glaze that may leech out when microwaved. Good quality stoneware mugs that cost a bit more will use good quality ingredients.

How long can stoneware mugs go in the microwave

For all stoneware mugs dishes it is best to only microwave for up to 2 minutes at a time. Add an additional minute if the liquid still needs to be heated.

You can use stoneware mugs to make cake in a cup but they should only take 90 seconds to cook.

Can you put stoneware mugs in the microwave? | Summary

Stoneware mugs can be used in the microwave if they are in good condition, made well and do not have any metallic edging or design. Stoneware mugs are perfect for cooking cake in a cup, reheating soups and making hot chocolate.