wht do ceremic mugs cracks

Why Do Ceramic Mugs Crack?

Welcome to my blog where you get to know all about all kinds of mugs and cups. Now I will not waste your much time as I know you are here to check, why do ceramic mugs crack? You want to know the reason behind the cracking of your beloved and precious ceramic crockery.

Don’t worry here you will get to know all those facts and fears that you want to clarify in your mind and heart about the Ceramic Pottery. The pottery that always attracts you whenever you see it in a supermarket crockery corner or anywhere else. But the fear of its cracking and breaking or even causing any health hazard stops you from buying it all.

So in this article, I have addressed all those queries which must have knocked your thoughts at least once when you have seen any broken or cracked piece of ceramic pottery. So let’s start with the very basic but important question.

Why Do ceramic Mugs Crack?

When we are talking about a ceramic cup crack. We first need to determine if it is a deep structural crack or flaw or it just happened in the superficial layer of your ceramic mug. Yes in ceramic ware we have an outer layer of glaze to cover the ceramics.

That glaze serves multiple purposes like coloring, decorating, and most importantly seals the porous surface of your earthenware. A ceramic without glazing is not able to hold the liquid as nicely as with glaze.

Deep Structural Cracks

Now let’s come to the point, where we need to check the crack type. If it’s a deep structural crack then definitely your mug has stumbled or fell somewhere. Such deep cracks are caused by any undue pressure or hitting.

These deep cracks can occur as a result of excessive heat as well, yes the ceramics are heat resistant, which means that they can bear certain temperatures. But they are not temperature-proof. So if the temperature in ceramics being changed abruptly from high to low or low to high can cause breakage.

Crazing In Ceramics Or Crack In Enamel Coat

The crazing or crack in the enamel is quite a mystery. As you just brought your new ceramic cup or a soup bowl. You just cherished your drink and washed it instantly after use to save it from any breakage or cracking. And you just saw it in a while and what’s that… there are several cracks or lines in the cup that you cant feel with the hand but can see those awkward lines.

Yes, these cracks are what we call a craze. So you might be shocked or surprised to see those lines which ruined your ceramic pot but you don’t know what caused them. Yes, my dear let me solve the mystery for you.

Actually, you just cherished your hot drink soup or coffee or tea and then out of care you washed it immediately after use. But this causes an immediate change in temperature while your mug is hot from the inside and the enamel coating outside got cold with water. These two different temperatures in the same bowl caused a tassel that resulted in the craze.

How To Protect Ceramic Mugs From Cracking?

Editor’s Pick

Clay in Motion Handwarmer Mug – Right Hand (Ocean Tide)

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Salient Features

  • Handwarmer Feature
  • Unique Ocean Tide Glaze


So if you want to protect your ceramic pottery no matter what so ever it is a or a plate or any other bowl. You need to be vigilant with few tips and that can add life to your ceramics.

    • If you are pouring anything hot in your ceramic pottery you better pour a bit of liquid first and then stir it evenly in the whole cup. So the mug adopts that hot temperature evenly and here you go add it all and enjoy.
    • While you are washing the ceramic cup or mug be careful to wash with not too warm and too cold water. As any extreme temperature change can cause the craze (enamel coating damage).
    • You must have read about the caution “place your medicine in cool and dry places” try to follow the same instructions with your ceramic. Because at times where we have extreme temperature i.e too cold or too hot your glaze can be damaged even while placed in a wrong shelf.
    • All the ceramics are made from heat and they can resist an oven anyways is just a myth. So do follow the instructions of the manufacturer before placing them in the oven.

Best Ways To Repair Your Cracked Ceramics

Editor’s Pick

Tea Forte Kati Cup Cherry Blossoms, Ceramic Tea Infuser Cup with Infuser Basket and Lid for Steeping Loose Leaf Tea

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Salient Features

  • Ceramic Infuser Cup
  • Delicate Cherry Blossom Design

If your precious ceramic cups are in danger of breaking or cracking and you need to rescue or repair them. Here are a few tips that are as easy as kids can do them and as effective that your crockery will get as good as new.

  • If your crockery is not broken but has a hairline crack that is not very visible through the naked eye but you can feel it with your hand. No need to be sad you are still in the capacity to rescue your ceramic. You don’t need rocket science for it but, german glue and warm milk will be enough ingredients to heal your broken piece of crockery. You just fill in the german glue in the crack and dip it in the lukewarm milk for two days and when you bring it out you will see a miracle happen and the crack already vanished.
  • If your crockery is broken in pieces even then there is a chance that you can fix it with white glue or epoxy glue. You just need to check that all the pieces are collected and joined well. You need to fix the glue nicely and firmly hold the joint for 60 secs and if you can’t hold the joint you can apply masking tape to keep the joint frim and fix.
  • You can join your broken cup handles or any broken jar or dish with this method. But I don’t suggest you use repaired ceramic to have your food from, yes but a broken handle or a jar lid or a bowl handle is ok to repair.

Is It Safe To Use Cracked Ceramic Cups and Pottery?

After the repairing issue is resolved the next issue is, Is it safe to use cracked pottery for food. Many consumers keep using ceramic crockery believe that if the crockery has a mild crack and nothing is seeping out it’s safe to use.

But that is a big no. You need to quit the cracked pottery as the cracks can harbor bacteria and other notorious and harmful creatures. So to be safe never let these harmful creatures get into your stomach and damage your health.

Once you see black lines in your ceramic mugs get alarmed because it’s nothing but bacteria and microbes families that are colonizing inside your crockery. And can slip into your food and then into your stomach and weaken your immunity.

Even if there is a craze in your mugs and you want to use it as technically it’s not cracked. But still, you need to avoid it as even a minor crack in the surface can give refuge to dangerous microbes.

Furthermore, the glaze surface of pottery contains lead and that lead gets added to your food when craze occurs. So the cracked or Glazed surface both are a big health hazard and must be not used to serve food to humans and not to your pets as well.

  • Do ceramic cracks in hot water?

Technically when you are pouring hot water or any hot liquid in your ceramics it’s not a problem but when you add hot water in a cold a mug that can cause damage.

  • What is the difference between cracking and crazing ceramic?

Cracking and crazing are both kinds of cracks but the craze is crack in the outer layer or glaze of the mug and a crack is deep into the surface.

  • Can warm milk repair the broken ceramic pottery?

Only warm milk cannot repair the pottery. That is just a myth but yes if you have applied any good adhesive on the broken piece of crockery and after that dip it in the milk you can repair the broken piece.

  • Which glue is best to use for your broken or cracked ceramics?

Any transparent glue can do wonders for you. I have tried and tested german glue even epoxies work well with the repairing ceramics.

  • What Causes black lines inside the mugs?

When the cracks are deep in the ceramic surface it causes black lines. Moreover, if the damage in the outer glaze gets old even then the cracks can get black due to lead present in the glaze.

Final Words

I hope this article will help you to sort out your issues related to ceramic mugs and crockery. If you have any other queries related to your ceramic durability and cracking and its possible health hazard feel free to talk to us.

We always welcome your positive suggestions and queries. Being a mug lover I always love to assist in any related issue. Moreover, my interest in the subject keeps me digging for the facts, and here in this blog I share all my research and try to figure out the best suggestions and best products for you.