Why Does Butter Spark In The Microwave?

Why Does Butter Spark In The Microwave?

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Why Does Butter Spark In The Microwave?

The answer comes down to the structure of fats. There are two types of fat molecules in butter: Triglycerides and phospholipids. Triglycerides are long chains of three fatty acid molecules joined together.

This is due to the hydrogen bonds that hold the triglyceride and phospholipids chains (types of fat molecules in butter) that start breaking up when heated, this type of fat forms a thin, stable film that is less likely to break up into chunks. 

One or two of these triglyceride chains will spark and leave the other two intact in “globules.”

The remaining chunks are still solid at room temperature, but once re-combined with other triglyceride chunks under heat, they will melt for good hence all the exploding butter.

On the other hand, Phospholipids are composed of a phosphorus-containing head group and two fatty acid chains.

The heads of phospholipids are polar, while the fatty acid portions contain no charge and therefore cannot dissolve in a polar solvent such as water.

When heated, this type of fat forms a thin, stable film that is less likely to break up into chunks than butter.

When heated in a microwave, phospholipids absorb microwaves and tend to heat evenly across the sample, not observed for butter.

These structural differences between the two types of fats are responsible for the differences observed in heating.

Why Does Some Butter Pop In The Microwave?

Butter is a simple mixture of milk solids and water that churns until they form a solid structure.

In different countries, the consistency of butter is primarily determined by the % of moisture present in the mixture, with higher moisture being more liquid.

At this stage, butter can be salted to add flavor or whipped to produce a firmer texture. Butter is also used in cooking as an ingredient due to its ease of use, rich flavor, and ability to brown food evenly.

Butter pops up in the microwave because the air pockets inside it contract as the butter heats. When the density of the butter reaches a certain point, it pops and makes a loud noise simultaneously.

This is precisely the same phenomenon as to why popcorn pops. It’s simply that popcorn pops because it contains more moisture than butter and produces a more sudden noise.

Microwaved butter contracts the air pockets inside it. The density of the butter becomes more extraordinary because of this shrinking until the density reaches a certain point.

At this point, the heat energy cannot transmit inside the butter anymore, and it becomes unable to contract further.

Thus, the air pockets suddenly contract violently and produce a loud noise simultaneously. Popcorn pops because its density increases through moisture evaporation rather than by shrinking.

The most interesting phenomenon is that sometimes no sound occurs even though you see that the butter has swollen or is bubbling like popcorn.

However, no matter how swollen the butter is, it will pop once the air pockets inside it shrink to a certain point.

The amount of air in the butter changes as it heats, so that even if no bubbles have appeared on the surface, they may still pop inside.

Why Is My Butter Popping?

Your butter is popping because it boasts too much air and sugar. This is due to the way you’re heating it.

You create little air and sugar pockets by separating the butter into a block, then cutting it up with a knife and whipping it quickly in a stand mixer.

These pockets can lift out of the butter more easily when heated, where they expand rapidly into puffy balls of air and sugar.

This happens because the air and sugar are trapped in the butter. They stay in the pockets until they become too large to fit in the butter, then they explode into a puff of air and sugar.

How Do You Microwave Butter Without It Exploding?

Butter mainly comprises fat. When you introduce heat to all that fat, the fat turns into steam and expands rapidly.

That rapid expansion can cause the butter to burst out of its wrapper and even the microwave.

Why Does Butter Spark In The Microwave?


When you’re rushing to get your butter melted and don’t have time to wrap it in duct tape, a few things can help you avoid your microwave becoming a butter bomb.

Vent The Microwave

Before placing the butter or margarine in the microwave, open the door and vent the microwave. This will let air flow out of it and prevent any pressure from building up in there.

Don’t Overfill The Microwave

If there’s not enough space inside your microwave to allow all that steam to expand, it can’t burst out of the wrapper and can’t clog your microwave up.

Choose the Right Wrapper

Check your butter wrapper to see if it’s specific for the microwave. If so, use that wrapper it’s less likely to melt and break.

Foil is a good option because it reflects heat and prevents the fat from turning into steam as quickly but still allows it to melt.

Should You Cover Butter In The Microwave?

Yes. You can cover butter in the microwave for quick and easy toasting for about 45 seconds.

When microwaving butter, the bubbles move around more quickly than when you put it in a pan on the stove, so it’s easy to burn your food outside.

The microwave keeps the butter from burning unevenly, which means you’ll get better-looking toast every time.

It’s best to do this in a covered dish so you can still see the lid and avoid splatters.

And while microwaving is an excellent way to turn butter into toast, it isn’t without its risks.

The microwaved butter will melt within a minute of microwaving and begin searing your food at the same temperature as cooked butter in the microwave.

How To Microwave Butter

  1. Cover the dish with a lid, then place it in the microwave for 15-20 seconds.
  2. Remove the dish from the microwave and stir. (It will be hot.)
  3. Cover again and return to microwave for 13-15 seconds.
  4. If there are still obvious signs of uncooked butter, repeat steps 2 and 3 until there is no longer any visible uncooked butter.

This method works best with a relatively clean microwavable container because your butter will splatter when it melts.

Is It OK To Put Melted Butter Back In The Fridge?

Yes. You can put the melted butter back in the fridge. Here are some advantages of putting melted butter in the fridge:

  1. It will cool down and solidify again, making it easier for you to scoop out and use.
  2. The fat will harden back up, making the butterless likely to spoil in the summer heat.
  3. If you want a cold pat of butter (like when used on desserts), you can quickly chill by sticking it in an ice cream maker or fridge freezer.
  4. If you put the whole stick back in the fridge, it will keep for some weeks.
  5. If you’re using the last bit of margarine or butter, it’s easier to extract when it’s solid.

But should you put the melted butter back in the fridge?

Some people say that the thinness of the butter would make it less likely to keep if kept like that.

So instead, they recommend putting the melted butter in a small container and freezing it. You could then use the frozen butter instead of keeping a large amount of melted butter in your fridge.

Why Did My Butter Explode On The Stove?

Your butter explodes on the stove because of the temperature difference between the outside air and your stove burner.

The heat from the flame causes water molecules in your butter to break down, forming hydrogen gas. The gas bubbles then explode violently for a few reasons:

  • When it passes into the cold area of your pot.
  • When it hits a nearby surface like metal or pumice stone.
  • When it comes in contact with liquid on an adjacent surface like water or vinegar.

After the explosion, foam of milk solids, buttermilk, and water will cover your pot. The solution is to pour boiling water over the pot to clean it.

Don’t worry about your safety: Milk solids are fully soluble in water and don’t pose a fire or explosive hazard.

If your butter starts to foam when you are churning it, you may have added pre-made buttermilk to the milk in your pot.

The buttermilk has a concentration of 4% butterfat and will boil like water.

You can keep your churn going by covering it with a towel or warm pot after each batch of boiling buttermilk pours out of the pot.

Butter is an emulsion of fat that floats on a water matrix. The water has not been evenly distributed within the butter when your butter starts to foam.

There is an imbalance in water molecules between your butter’s top and bottom portions.

This causes them to separate, then contact each other at high temperatures, causing a dramatic release of hydrogen gas that boils off in an explosion.

Can You Remelt Melted Butter?

Yes. You can remelt melted butter if you know the science behind it. When you heat the butter, then cool it, it does not solidify into a new form.

It goes through a re-crystallization process where sugar molecules in the butter start to rearrange themselves and reform bonds with other sugar molecules, helping to create that classic hard texture you know and love.

However, if you remelt something that has gone through a process of recrystallization, then most of the time, it will lose its final structure.

Even if you don’t refrigerate it, butter that you have melted and then cooled will do the same thing.

The tiny holes and crevices in the crystals created during the remelting process will attract other water molecules, causing the butter to separate into liquid and solids.

When you take out butter from the refrigerator or a cooler, you need to give it time to warm up a bit before you can spread or use it.

The same thing happens when you pour melted butter into a microwave heated and cooled mug.

If you haven’t noticed, you’ll end up with solid butter at the bottom and watery, runny butter at the top.

Stirring will not always help because the process of recrystallization is already in motion.

Why Does Nutella Spark In The Microwave?

Nutella sparks in the microwave because the mix contains sugar. If you pour the melted chocolate into a microwave-safe bowl, it will have finished cooking by the time you finish adding ingredients.

The lower temperature of the melted chocolate isn’t enough to thoroughly cook fat molecules, so they stay liquid in some places and slightly solid in others.

When you heat the chocolate, it heats unevenly around the edges, causing portions of the chocolate to solidify unevenly, generating sparks.

The mixture cools and hardens quickly,this is not a problem for microwaves. If you allow the mixture to cool for some time, mix again before heating it.

A much smaller number of sparks can occur. It’s also possible that Nutella’s high-fat content makes it very sticky in some places.

When something is hot, molecules move faster because of the high temperature. Mean speed is the average speed of a molecule in a gas.

The mean speed ranges from 0ºC to 150ºC at -10ºC to 100ºC, with an average of around 50ºC.

At room temperature, the average molecular speed is around 3 km/h, and the heat moves faster than this value by 2.5.

Faster moving molecules strike the wall and other objects more. Molecules striking a surface bounce off it and change their speed.

If they contact something, they can speed it up or slow it down.

What Is That White Stuff In Melted Butter?

The white stuff in melted butter is what’s leftover from evaporated milk.

As milk heats, the water in it boils off. When the milk reaches about 180 degrees Fahrenheit, tiny droplets of butter, solidified from their storage in the fridge, break free and mix with the hot milk.

At this point, milk becomes a thick liquid called “cream.”You can make butter by churning cream until it separates into buttermilk and butter.

You then drain off the buttermilk, leaving pure, solid butter. The process produces a lot of liquid called “buttermilk,” rich in protein, vitamins, and minerals.

Since butter boasts making by churning cream, it contains all the good stuff leftover from the buttermilk. If you heat a stick of butter and leave it sitting out overnight.

The goal is to evaporate off all the water you can. What’s left behind is nearly pure butterfat.

There can be up to 8 percent or less water in just-churned butter and much other stuff that falls out of the solution when heated, like milk solids and proteins.

Dried milk proteins and some sugars are a by-product of the evaporation process, which mix with the butterfat to form a milky, solid material.

This stuff gives melted butter its “off” white color. When you see the gloppy stuff in melted butter, it’s clear that there is more than just melted fat from cream.

Can You Refrigerate Microwaved Butter?

Yes. You can refrigerate microwaved butter. 

Many people think that microwaveable butter is not safe  once you heat it, but your food should be fine, provided it softens when you apply pressure.

Microwaves have a very short wavelength and a low density of energy.

This means that the water molecules in butter are too large for microwaves to penetrate and heat them.

The butter will not melt because water molecules are too large, and water is a poor conductor of heat.

However, the butter will become softer at a lower temperature, allowing its usage as an ingredient in baking.

Be careful, though; microwaved butter on bread can cause a burning sensation on your tongue.

Butter does not cool down completely before it hits the outside of the bread but instead melts at room temperature before hitting it so that it can burn your taste buds.

To avoid this, you can chill the bread before eating it.

You should leave it out for about 10 minutes to cool down to reach room temperature, but it will not burn your tongue once you put the butter on it.

Are Ghee And Clarified Butter The Same?

Ghee comes from the same milk solids removed from milk using double cream separation. This process is the same method used to make butter.

The only difference is that the milk solids, water, and other by-products don’t boast re-incorporation into the butter to make ghee.

Ghee vs. Clarified Butter

The resulting product comes from clarified butter, where they have removed almost all the water and filtered out any milk solids.

Ghee has a nuttier flavor from its browned milk solids left behind during processing. It also boasts a lower melting point, making it ideal for cooking.

Clarified butter doesn’t taste the same as standard butter. It’s further processed to remove all milk solids, and they often add coconut milk for flavor.

This results in a milder butter that is easier to spread on bread or use in cooking and baking.

You may prepare foods that call for clarified butter with ghee and regular unsalted butter. Although the two ingredients may look similar, they taste entirely different.

Thus, it’s essential to pay close attention when shopping for the butter of your choice or ask the cook at the restaurant which one they prefer.

What Is The Foam On Top Of Melted Butter?

The foam on top of melted butter results from the proteins in the butter “breaking down.”

You might have noticed that this foam is thicker when you first melt the butter in the microwave.

The heat from microwaves “breaks down” these proteins more quickly than if you just used a pot on your stove. The protein breakdown also changes how much air it contains.

Meaning that as more water evaporates and there are fewer water droplets, this foam becomes thicker and looks more like whipped cream than fluffy butter with bubbles in it.

The proteins in butter, called caseins, actually sit directly on the surface of the liquid fat.

When you melt butter, that fat breaks down into smaller droplets, and some proteins will stick to these tiny fat particles.

Since there is less space between these tiny fat droplets and more proteins sitting on top of them, there is more protein than fat in this foam.

Butterfat comprises 9% water, 86% triglycerides, 7% caseins, and 1% milk proteins. After there is no water, the remaining fat comprises unsaturated and saturated fatty acids.

Unsaturated fatty acids turn liquid above 120° C. The butterfat comprises about 90% saturated and 10% unsaturated fatty acids.

But the amount of each varies from butter to butter and from batch to batch.

The melting point of unsaturated fatty acids varies from 20 to 40° C, while that of saturated fatty acids varies from 40 to 60° C.

Why Does Butter Taste Different When Melted?

Butter tastes different when melted because it changes from a solid to a liquid. When it is solid, the butter is smooth and creamy.

When it melts, the milk fats separate and become more liquid-like than when they are in their regular form.

Besides changing texture, melting butter also changes its flavor. When the butter is solid, it is rich and full-flavored, with a particular character people describe as a “buttery” flavor.

However, when the butter melts, the milk fat separates from the water. Depending on how long the butter melts and what heat source it’s heated on, there can be different flavors.

Some people describe this as a “burnt” flavor of “fats” or an aroma similar to that found in popcorn or nuts.

You may add sugar, water, and other ingredients to a butter mixture to give it that “toasted” flavor.

Note that people judge the quality of melted butter by its visual appearance and taste.

For example, if a store’s butter has a liquid look when melted or has “scumming” at the top or sides of the pan where it’s melting.

People might not buy that product because they won’t trust that particular batch of milk fat.


Butter popsicles exist, and you can make them yourself.

They are a great way to cool down during those hot summer days, and they make for a fun activity you can do with your kids or friends.

The best part is the versatility that a butter popsicle has.

You can use them for many things, from dessert to a snack or even as a sweet treat when you need something to eat that can melt for immediate consumption.

Pop the fruit and flavor of your choice into the freezer, pop and enjoy it when you are ready to eat it.


Hi! I' am Tom. I was a manager in one of the biggest stores for over 10 Years, am also an SEO by night. I don't like to call myself a blogger; they are very analytical, do email marketing, and know all SEO stuff. I faced many questions from customers about different products, and there was hardly any help on the internet. After learning all the things about these products as a manager the hard way, I decided to start a blog and help other people.

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