The Science of Why Pizza is So Greasy (and How to Reduce It)

  • By: Mike
  • Date: September 14, 2023
  • Time to read: 6 min.

Why is pizza so greasy? Let’s sort this out. Pizza is one of the most beloved foods across the globe. The irresistible combination of dough, cheese, and sauce makes it hard to stop after just one slice.

However, the pool of oil glistening on top of a fresh slice isn’t always so appetizing. Understanding the science behind why pizza tends to be greasy can help you learn how to make less oily pizzas at home.

Why Pizza is Greasy

As easy as it might be to say “it’s greasy because its pizza”, a little more thought needds to be put into this. Basically, there are a few key reasons why pizza ends up so greasy, here they are:

1. The Type of Cheese

One of the main culprits for greasy pizza is the cheese. Traditional mozzarella contains about 50% fat and 20% moisture. Low-moisture part-skim mozzarella contains 30-40% fat. The high fat content means more oil can leach out during baking.

Soft fresh mozzarella contains the most moisture at 50-60%. This leads to less grease during baking but can make the cooked pizza soggy. Hard aged cheeses like parmesan tend to be lower in fat and moisture.

2. How the Cheese is Prepared

Along with the type of cheese you choose, how it’s prepared affects greasiness. Shredded cheese has more surface area and melts faster. This causes more fat and oil to leach out compared to cheese sliced from a block.

Grating cheese also creates more surface area leading to greater grease. Newly shredded cheese tends to be greasier than pre-shredded which has dried out a bit.

3. Location of Cheese

Where you place the cheese on the pizza impacts grease levels. Cheese directly placed on top of the sauce will lead to a oilier pizza. The sauce keeps the cheese from drying out as it melts.

Cheese placed under sauce or toppings will absorb more oil. Toppings also form a barrier to prevent cheese grease leaking onto the surface.

4. The Pizza Dough

The dough itself also plays a role. Higher fat doughs like deep dish or Sicilian-style will be greasier than thin crust. Having a well-floured dough prevents sticking and reduces the amount of oil needed during shaping and stretching.

Overworking and dense doughs prevent even rising and moisture evaporation. This leads to a tighter crumb and more retention of oil during baking.

5. Cooking Methods

How you cook the pizza also affects grease levels. Ovens heated to high temperatures (around 500°F) set the cheese quickly which prevents excess oil release. But lower temperature home ovens (350-450°F) cause the cheese to slowly render more fat.

Cooking directly on a pizza stone allows excess moisture to evaporate compared to pans. But if the stone isn’t pre-heated enough, the dough will stick and require more oil.

Finally, taking steps like dabbing or blotting cheese pizza after cooking can remove visible pools of grease. Now let’s look at some ways to reduce the oil and grease when making homemade pizza.

How to Make Less Greasy Pizza

With all these factors that lead to oily pizza, there are plenty of ways you can adjust your methods to produce a crispy, melty pie that’s not a greasy mess:

1. Use Less Fatty Cheeses

The easiest way to cut down on grease is to use reduced-fat cheese options. Part-skim milk mozzarella contains 30-40% less fat than whole milk mozzarella. Low-moisture part skim mozzarella has even less fat at around 20%.

You can also combine high-fat and low-fat cheeses. Use part-skim mozzarella along with some Parmesan, Pecorino Romano, or aged Provolone that contain less than 20% fat. The flavor will still be there but with less grease.

2. Grate or Slice Cheese

Buy cheese in block form and grate or slice it yourself instead of using pre-shredded cheese which melts into oil faster. Take slices from the block and layer them on your pizza instead of shredding for a less greasy finish.

If you do shred cheese, do it in short quick bursts and let it dry out a bit before topping pizza with it. This prevents clumping from friction heat when shredding.

3. Place Cheese Strategically

Construct your pizza by first adding sauce to the dough, then cheese, then toppings. The toppings will shield the cheese from direct heat allowing it to melt more gradually.

Some chefs even recommend shredding cheese and placing it under the sauce to further protect it. Just be sure to leave some cheese exposed for appetizing stretched melty bites.

4. Choose Lean Dough

When making the dough, avoid high-fat recipes like deep dish or Sicilian-style. Opt for a classic thin crust or margherita dough with 00 or bread flour that requires little oil.

Let the dough proof sufficiently to develop flavor without extra fats. Handle the dough gently when shaping to prevent tearing that requires extra oil to repair.

5. Preheat Your Oven and Stone

Ensure your pizza stone or steel is preheated for at least 30-60 mins at the highest temperature your oven allows, ideally around 500°F. The hotter the surface, the less time cheese has to exude grease before setting.

Heat the oven at least an hour before baking. This allows heat to fully penetrate for a high temperature that cooks the crust quickly.

6. Finish on the Top Rack

Start cooking the pizza on the bottom rack to crisp the bottom crust. Then transfer to the top rack 2/3 of the way through baking to finish. This “top ticking” browns the top faster to set the cheese and prevent oil leaking.

7. Blot Excess Grease

Once the pizza comes out of the oven, use a paper towel or cloth to gently blot any excess oil pooling on the surface. This wicked away grease without impacting the crust.

The Science of Pizza Grease

Now that we’ve covered how to reduce pizza greasiness, let’s take a deeper dive into the science of what exactly is happening when all that oil leaks out.

Pizza grease is actually a water-in-oil emulsion. This means small droplets of water mixed into a continuous phase of fat and oil. And emulsions are thermodynamically unstable mixtures – they want to separate into water and oil components.

This process is called coalescence and it happens during cheese melting. Heat causes the fat to become less viscous and separate from the water droplets. The fat then leaks out along with milk proteins and Lactic acid crystals carrying flavor.

But why does cheese release so much grease when baked on pizza versus other recipes? It comes down to temperature and moisture.

Pizza ovens heat up past 500°F, while home ovens hover around 400°F. At these high temperatures, the cheese components break down faster.

Moist toppings like sauce keep cheese hydrated, allowing more time for fat and water to separate as it melts.

Whereas in something like lasagna, moisture evaporates in the oven. This dehydrates the cheese surface preventing coalescence of fats.

The takeaway is that traditional pizza preparation encourages the perfect environment for those delicious, flavorful fats and oils to express themselves in all their greasy glory.

Alternative Pizza Styles for Less Grease

We’ve covered plenty of tips for making traditional pizza less greasy. But if you enjoy the convenience of takeout or restaurant pizza, some styles and recipes lend themselves to less oil.

Thin Crust Pizzas

Thin crust pizza like Neapolitan or New York style often use less cheese and toppings than a Chicago deep dish or pan pizza. This restrained use of cheese means less opportunity for grease to leak out.

Vegetable-Topped Pizzas

Veggie pizzas with mushrooms, onions, tomatoes, peppers, etc. tend to release less oil compared to piles of pepperoni and sausage. The water in the vegetables hydrates the cheese curbing separation of fat.

White Pizzas

White pizzas utilize olive oil, garlic, herbs and Parmesan instead of tomato sauce. The lack of watery sauce helps reduce the grease factor.

Hawaiian Pizza

Hawaiian pizzas with ham and pineapple are lower in fat. The sweet pineapple juice also hydrates the cheese preventing grease release.

So if you want to enjoy pizza out while avoiding an oil slick, look for these menu options cooked in a hot oven. And use the techniques in this guide to make homemade pizza that’s melty and delicious but not a greasy mess.


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