What Causes A Microwave Plate To Break?- Understanding Causes and Solutions

It happens to everyone—you’re reheating leftovers or cooking a frozen dinner in the microwave when you hear a loud “pop” and your plate breaks. This can be scary, inconvenient, and messy. However, microwave plates break for what reason?

The causes of microwave plates cracking under heat and how to prevent them will be discussed in this article. By knowing what stresses these plates, you can choose the suitable cookware and employ proper practices to avoid breakage. We’ll discuss thermal shock, uneven heating, plate flaws, moisture damage, and more. Discover what causes a microwave plate to break and how to prevent them.

What causes a microwave plate to break?

Microwave Plates 

Microwave plates are designed to cook food in microwave ovens. Material options include glass, ceramic, and plastic. Glass and ceramic plates are increasingly popular since they can endure high temperatures and transmit heat evenly. High microwave temperatures can distort plastic plates.

Microwave plates have many uses:

  • Allow food to cook evenly: Compared to normal plates, glass and ceramic cook food equally. Prevents cold or undercooked spots.
  • Prevent food splatters: To minimize food splashes and spills when cooking, microwave plates generally have raised edges.
  • Safe microwave removal: Glass and ceramic plates heat up and cool quickly. Special grips or ridges allow plate-grabbing without scorching hands.
  • Microwave and oven safe: Glass and ceramic plates can be used in the microwave, oven, or stovetop.
  • Provide an appropriate surface for microwaving: Microwaves work best on non-metal, smooth surfaces. Microwave plates meet safety standards.
  • Microwave-safe shapes and sizes: Single servings or meals can be cooked on round, rectangular, or split plates.

Thermal Shock

Second reason- What causes a microwave plate to break? Thermal shock is a leading cause of microwave plate fracture. Thermal shock occurs when the plate temperature changes rapidly, causing various parts to expand at different speeds. Uneven expansion stresses the plate material, causing cracks or breakage. 

Due to uneven heating, microwave plates often experience thermal shock. Some portions of the plate absorb microwave energy and heat up quickly, while others stay cool.


A platter containing cold food on one side and hot food or fluids on the other will have a strong temperature gradient. The plate bends because the heated side expands more than the cold side. Reheating meals repeatedly fatigues and cracks the plate.

Plates with thermal shock resistance can prevent breaking. Microwave-safe plates use materials that distribute heat more evenly. This reduces shock strains and temperature gradients. Correct microwave use is also important, as discussed below.

Uneven Heating

Food vibrates rapidly and heats up in microwave ovens because water molecules absorb microwave energy. However, microwaves don’t always diffuse evenly in ovens. Uneven heating of food and microwave-safe dishes can result.

Hot and cold patches result from unequal food heating. Food with greater moisture heats up faster, while dry parts stay chilly. Heat pools in hotspots due to this imbalance. 

Microwave plates and dishes behave similarly. Parts of the plate absorb more microwave energy if their thickness or composition varies. Hotspots heat up faster than the rest of the plate.

Plate thermal strains result from high temperature differences. Cracks or complete fractures form when the hot area expands while the cooler area stays steady.

Due to uneven heating, microwave plates often crack. To uniformly disperse microwaves, stir or rotate food often. Controlling power can also reduce hotspots. Utilizing oven-safe and microwave-safe plates will help to prevent overheating weak spots.

Old or damaged plates

Another reason- What causes a microwave plate to break? Used or broken plates might crack and break in the microwave. Plate scratches, chips, and cracks are vulnerable spots. Plate materials erode over time. 

Glaze defects, crazing, micro-fractures, and deformations can occur. These often go undetected, yet they weaken the plate. Heat cycling from microwave use worsens these issues. Material fatigue makes the plate more likely to shatter under thermal stress.

Small daily wear and tear chips, cracks, and scratches can be disastrous. When microwaved rapidly, the damaged region expands faster than the remainder of the solid structure. This creates stress concentrations exceeding a plate’s capacity. That weak location will cause a plate-wide fracture.

Stop microwaving older dishes if they have chips, cracks, or scratches. Unsafe for thermal shock due to damage. Replace old plates with new, defect-free ones to avoid breakage. Carefully handle them to avoid flaws.

Improper Use

Incorrect use is a leading cause of microwave plate breaking. The plate material can crack or shatter if the oven’s power is too high. Plates that can tolerate microwave energy are microwave-safe. A microwave with a power output of 1100 watts or more thermally stresses a plate.

Overheating the plate is another mistake. Despite the correct power, extended microwave exposure might create microscopic plate fractures or weaknesses. Breakage rises with exposure time. Heating a dish for 10–15 minutes stresses it more than 30 seconds. Always follow directions, don’t overheat, and let plates stand before removing them.

Moisture Damage

There are two main ways moisture damages microwave plates. First, soup and microwave steam can condense under or along plate edges. Trapped moisture significantly lowers the plate surface temperature. Hot plates experience more thermal shock when they meet colder, damper sections, increasing the risk of cracking or breaking. 

Second, heated plates cool faster when water splashes on them. Extreme temperature changes degrade plates over time. Moisture worsens thermal shock on heated plate surfaces.

Wipe plates after use and avoid microwaving wet or messy foods directly on them to avoid moisture damage. Plates should be at room temperature before washing to avoid quick chilling. Check plates routinely for hairline cracks that let moisture in. Discard damaged plates.

Manufacturing Defects

Microwave plates can crack owing to manufacturing defects. Poor manufacturer quality control might cause plate flaws that crack or shatter when heated. The structural integrity of microwave plates can also be compromised by poor manufacturing. What causes a microwave plate to break?

To ensure glass and ceramic plates can resist microwave heating cycles, they are produced under strict circumstances. However, shortcuts or quality control errors might result in plates with microscopic faults or cracks that grow when heated and break. Why does a microwave plate break? 

Chemical issues in glass or glazing can also cause concealed faults. Contaminated or substandard raw materials weaken plate molecular structure. What causes a microwave plate to break? Not evident at first glance, these manufacturing faults can cause plate failure when used. Durability and safety testing during production can catch and delete problematic plates. What causes a microwave plate to break?

Preventing Breakage  

The easiest approach to avoiding microwave plate breakage is to follow instructions and watch for damage. Here are some tips:

  • Read the microwave-safe cookware manual and follow any instructions. Cook within the recommended time.
  • Cool plates slowly before handling to avoid rapid temperature changes. Avoid ice and cold water on hot plates. 
  • Avoid dishes with chips, cracks, or other damage. Check wear and tear frequently.
  • Make sure microwave plates fit without touching the sides. Avoid overfilling food containers.
  • Clean the plates and avoid dampness. Spilled food or water can cause fissures.
  • In the microwave, avoid metal utensils and aluminum foil to avoid arcing.
  • Stop using plates that smell scorched or have fractures. Materials may be contaminated.
  • Consider replacing plates after several years of heavy use. Old plates break more easily.
  • Select high-quality microwave-safe plates. Avoid inexpensive, crackable models.

Avoid irritating kitchen breakage by following recommendations, examining for damage, and replacing worn plates. Carefully handling microwave plates extends their lifespan.


What causes a microwave plate to break? Overall, various causes can cause microwave plate breakage:

Use microwave-safe dishware, handle it gently, and use the microwave properly to avoid uneven and excessive heating. Carefully maintained microwave plates should last for a long period. But knowing the reasons for breakdowns might prevent frustrating occurrences.

  • Thermal shock: A cold plate can split or shatter when microwaved rapidly. Materials expand when heated, causing thermal shock.  
  • Uneven heating: Hot spots in microwaves cause uneven plate heating. Rapidly heating areas expand more than cooler ones, causing stress and cracking.
  • Old or damaged plates: Due to pre-existing flaws, cracked, chipped, or worn plates may break in the microwave.
  • Improper use: Heating plates for too long, using too much power, or handling hot plates carelessly can cause thermal stress and cracks. 
  • Moisture damage: When rapidly heated, water trapped under plates while washing might break them. Food spills can also weaken.
  • Manufacturing defects: Microwave-safe plates should withstand thermal shocks. Sometimes material or production defects cause weakness.

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