Mozzarella is a soft, mild cheese that is a key ingredient in many Italian dishes like pizza, lasagna, and calzones. When baking or cooking with mozzarella, it’s common to see it turn golden brown or develop brown spots. This browning can happen for a few different reasons.
Why Mozzarella Browns
Here are some of the main causes of mozzarella browning in the oven:
- Caramelization – When mozzarella is exposed to high heat, the sugars naturally present in the cheese can undergo caramelization. This process causes the sugars to brown, resulting in a golden or brown exterior.
- Maillard Reaction – This is a chemical reaction between proteins and sugars that requires heat. It also produces a brown exterior on foods like mozzarella.
- Dehydration – As mozzarella bakes, the high heat of the oven can cause some of the moisture to evaporate. This drying out concentrates the proteins and sugars, allowing caramelization and Maillard reactions to occur more quickly.
- Browning Enzymes – Enzymes like lipoxygenase can cause fats in mozzarella to oxidize when heated, leading to browning.
Is Browning Harmful?
In most cases, the browning and discoloration that develops on mozzarella during baking is harmless. It does not indicate the cheese is spoiled or unsafe to eat. The brown spots are simply aesthetic changes due to chemical reactions with the heat. The browning can make the mozzarella take on a more complex, nutty, toasted flavor in some instances.
When Browning May Be a Problem
While typically benign, mozzarella browning can be a problem if:
- It burns or becomes blackened – This indicates the cheese is overcooked.
- It happens within a very short cooking time – Browning that happens too fast may mean the oven temperature is too high.
- It occurs evenly over the entire surface – Even, deep browning can signal overcooking.
- The cheese tastes bitter – Burnt flavors mean it has been overbaked.
As long as the mozzarella only develops light, spotty browning and still retains a creamy interior and mild flavor, it is still perfectly safe to eat.
Preventing Excess Browning
While a little browning is normal for mozzarella in the oven, you can minimize it by:
- Using low-moisture mozzarella – Fresh mozzarella has a high moisture content, which evaporates quickly and leads to more browning. Low-moisture mozzarella is firmer and less prone to browning.
- Controlling oven temperature – Don’t overheat the oven. Bake at moderate temperatures like 350°F – 375°F.
- Preventing direct heat exposure – Shield the cheese from direct contact with the oven rack or heating element using foil or a pan.
- Covering it while cooking – Trapping some steam under foil or an inverted pan will reduce drying.
- Checking it frequently – Keep an eye on the cheese as it bakes and remove it as soon as light browning appears.
- Using anti-browning agents – Some recipes add acids like lemon juice to slow down Maillard reactions.
Is Browned Mozzarella Safe to Eat?
In most instances, browned or discolored mozzarella that hasn’t burnt is perfectly safe to eat. The brown color does not mean the cheese has gone bad or become hazardous.
Here are some signs the browned mozzarella is still safe:
- It retains a creamy, supple interior when cut.
- It does not taste excessively salty or bitter.
- There are no off odors like ammonia, sourness or rotting.
- Any brown areas are mild and shallow, not blackened or charred.
- There is no mold growth.
- It has not exceeded its use-by date if commercially packaged.
On the other hand, mozzarella that is badly burnt with a charred black exterior or acrid, overpowering flavors should be discarded.
When in Doubt, Throw it Out
If you have any uncertainty about the safety of browned mozzarella, it is best to throw it out. The risks of possible foodborne illness are not worth eating questionable cheese.
How to Store and Maintain Freshness
To get the longest shelf life out of mozzarella and minimize premature browning, follow these storage guidelines:
- Refrigerate below 40°F as soon as possible after purchasing.
- Keep it in its original brine packaging or submerged in fresh brine.
- If using fresh mozzarella, drain excess liquid before storing.
- Place in an airtight container if not in brine.
- Avoid freezing mozzarella unless absolutely necessary. Freezing can damage the texture.
- Use within 5-7 days for fresh mozzarella.
- Use low-moisture mozzarella within 2-3 weeks of opening.
Proper refrigeration is key for maintaining the freshness and shelf life. Discard any mozzarella that develops mold or smells bad.
When cooking with mozzarella, keep these tips in mind:
- Choose low-moisture mozzarella for baking, as it holds up better under heat.
- Shred or cut into small cubes for more even melting.
- Bring ingredients like sauce and cheese to room temperature before baking for more cohesive melting.
- Preheat oven fully before baking and use oven thermometer to ensure accuracy.
- Avoid overcrowding pan, which can cause uneven heating.
- Use pan or foil to prevent direct oven rack contact if concerned about browning on bottom crust.
- Check frequently toward end of baking time and remove once light browning appears.
Taking steps to moderate oven temperature, prevent direct heat exposure, and monitor doneness can help minimize excess browning.
Frequently Asked Questions
Is it safe to eat browned or burnt mozzarella?
Lightly browned mozzarella is generally safe if it hasn’t developed a burnt taste or smell. Severely burnt or blackened mozzarella should be discarded.
Why does my fresh mozzarella turn brown so quickly in the oven?
Fresh mozzarella has a very high moisture content that evaporates quickly in the oven, jumpstarting browning reactions. Low-moisture mozzarella is less prone to fast browning.
Can you reverse browning or discoloration in mozzarella?
Unfortunately, once mozzarella has started to brown, the chemical changes cannot be reversed. The best option is to prevent or minimize browning from the start.
What’s the best way to store mozzarella?
Refrigerate mozzarella sealed in an airtight container below 40°F. Store in its original brine if possible. Avoid freezing.
Can mozzarella be refrozen after thawing?
It’s not recommended to refreeze thawed mozzarella. Refreezing can damage the texture and encourage spoilage.
The Bottom Line
It’s common for mozzarella to take on a light golden brown or spotty discoloration when baked in the oven. This browning is generally harmless and does not mean the cheese is unsafe if it has not taken on burnt flavors. To minimize browning, use low-moisture mozzarella, control oven temperature, prevent direct heat exposure, and monitor doneness closely. Proper refrigerated storage helps maintain freshness and quality. While a little browning is ok, deeply charred or burnt mozzarella should always be discarded.