Why Pizza Becomes Tough When It Cools and How to Preserve Its Freshness [What Makes Baked Goods Go Stale]

We’ve all experienced how pizza becomes tough and leathery as it cools, or how bread loses its softness over time. But what causes this, and how can we prevent it? In this article, we’ll explore the science behind staling and freshness loss in baked goods, along with practical tips to keep your pizza softer for longer, and extend the shelf life of your other baked goods

Introduction: What Happens to Baked Goods as They Cool and During Storage

From the moment baking ends and baked goods leave the oven, several ongoing processes affect their texture and overall eating quality. These changes occur continuously, impacting both the short term (mainly for pizza) and the long term (for bread and other baked goods).

Three main processes contribute to the staling, loss of freshness, and toughening of baked goods:

1. Starch retrogradation: Changes in starch structure that cause the crumb to lose its softness and become firm.
2. Moisture migration: The movement of water from the crumb to the crust.
3. Changes in gluten structure: Transformations in the gluten structure that result in a tougher, chewier texture.

Among these processes, which occur simultaneously, starch retrogradation plays the most significant role in staling, causing baked goods to lose their softness and freshness and become tough.

These changes begin as soon as baked goods leave the oven and continue indefinitely, unless halted by freezing (more on that later). They affect all flour-based baked goods (and other food containing starch such as potatoes and rice), with the rate and extent of each process depending on various factors, which we’ll explore later.

1. Starch Retrogradation

Starch retrogradation is the primary process responsible for baked goods becoming stale and losing their softness and freshness.

In the following sections, we’ll explore what starch retrogradation is, how it occurs, the factors that influence it, and how it can be slowed and even [partially] reversed.

Starch Retrogradation: General Background

Simply put, starch retrogradation is the reverse mechanism of starch gelatinization, a process explained in detail in the article From Dough to Pizza: A Deep Dive into the Processes Occurring Inside the Dough During Baking.

In short, during gelatinization, starch absorbs water, swells, and its molecules lose their crystalline structure, giving baked goods their characteristic softness and texture.

Retrogradation, on the other hand, is the opposite process, where starch molecules lose their amorphous structure and recrystallize. This results in a denser starch structure, making baked goods lose their softness.

Due to the differences between pizza and bread, starch retrogradation occurs at different rates:

• In pizza: The baked dough – especially the crumb – quickly loses its softness and tenderness, becoming tough as it cools, often within minutes after leaving the oven.
• In other baked goods (such as bread): Over time, the crumb gradually loses its softness, becoming tough and developing a crumbly or “grainy” texture. For a loaf of bread, this process unfolds over hours to days.

How the Retrogradation Process Occurs

Starch makes up about 75% of flour and consists of two main molecules: amylose and amylopectin.

• Amylose accounts for roughly 25% of the starch in flour. It has a linear, helical structure without branches, composed of hundreds of glucose units (monomers).
• Amylopectin makes up about 75% of the starch in flour. Its structure is highly branched, and consists of thousands to hundreds of thousands of glucose units.

During retrogradation, the starch molecules, having gelatinized during baking and lost their crystalline structure, begin to recrystallize:

1. Amylose molecules rapidly recrystallize, binding together to form double helix-like structures (double helices). Due to amylose’s linear structure, this process occurs quickly, within minutes to a few hours.
2. Amylopectin molecules also re-crystallize, but because of their complex, branched structure, this process is much slower, taking place over hours to days.

Because of these structural differences, the rates of retrogradation vary:

• Amylose retrogradation happens very quickly, which is why pizza dough toughens and loses its softness almost immediately after baking.
• Amylopectin retrogradation occurs more slowly, leading to the gradual staling and quality loss of baked goods over time, such as a loaf of bread.

The Retrogradation Process: Illustration and Steps

The following diagram illustrates the stages of the retrogradation process:

1. Crystalline structure before baking: In the dough stage, starch molecules are in their initial crystalline form.
2. Gelatinization: During baking, as the dough heats up, starch absorbs water and swells. This causes the starch molecules to lose their crystalline structure and transition into an amorphous state.
3. Onset of retrogradation after baking: The retrogradation process begins as soon as the baked goods come out of the oven and start cooling.
4. Retrogradation of amylose (formation of double helices): Amylose molecules rapidly recrystallize, binding together to form structured, double-helix-like formations.
5. Retrogradation of amylopectin: Amylopectin molecules undergo slower retrogradation, gradually returning to their crystalline structure.
6. Water expulsion from the starch structure: As retrogradation progresses, the recrystallizing starch molecules create a denser structure, forcing out some of the water trapped within. This [new] free water migrates to other areas of the baked dough. The shift in water content contributes to the toughening of the baked product and the loss of softness.
7. Texture changes: As retrogradation continues, the baked goods become firmer and lose their ‘fresh’ texture.
8. Reversing retrogradation [reheating]: Reheating baked goods can temporarily reverse retrogradation. Heat breaks down crystalline structures in the starch, redistributes moisture, and returns some molecules to an amorphous state, restoring softness.

Factors Affecting Retrogradation (Rate / Extent)

Several factors influence the rate and extent of retrogradation in baked goods. Some of these can be controlled relatively easily, while others are more difficult to manage.

In general, the more gelatinization that occurs during baking, the faster retrogradation will occur. This is primarily due to increased amylose leakage: greater gelatinization results in more amylose leaking from starch granules, which enhances its potential to recrystallize (form double helices). In other words: higher amylose leakage accelerates retrogradation.

The key factors affecting the rate and extent of starch retrogradation include:

• Baking temperature
• Moisture content
• Ratio of amylopectin to amylose in the flour
• Fat content in the dough
• Sugar content in the dough
• Storage conditions
• Cooling rate
• Use of dough conditioners/improvers

In the following sections, we will explore each of these factors in detail.

Baking Temperature

In general, higher baking temperatures accelerate retrogradation, causing baked goods to lose their softness more quickly. This effect is particularly noticeable in pizza, which is especially prone to rapid retrogradation (a topic we will explore in more detail later).

At higher baking temperatures, more water evaporates during baking, making additional moisture available for gelatinization. This leads to a greater degree of starch gelatinization, resulting in increased amylose leakage into the dough. As mentioned earlier, the more amylose that escapes, the faster retrogradation occurs.

Moisture Content

The higher the moisture content in baked goods after baking, the slower the retrogradation process.

Free water in the dough interferes with the bonding of starch molecules (mainly amylose), disrupting their ability to form hydrogen bonds and recrystallize. Additionally, water acts as a plasticizer, helping maintain the flexibility of the gelatinized starch network as it cools, which delays the hardening of the baked goods.

In general, the more water a dough retains (or the less it loses during baking or storage), the slower retrogradation occurs, helping baked goods stay soft and fresh for longer.

The Ratio of Amylopectin to Amylose

Starch from different sources has varying ratios of amylose to amylopectin. Generally, the higher the amylose content in the starch, the faster retrogradation occurs.

For example, white flour contains a relatively high level of amylose (around 30%), while sticky rice has a much lower amylose content, typically up to 3%.

Fat Content in the Dough

Adding fat to dough slows down retrogradation through several mechanisms:

• Fat molecules create a physical barrier between starch molecules (mainly amylose), preventing them from binding together.
• Fat molecules can form chemical bonds with starch molecules, disrupting their ability to undergo retrogradation.
• Depending on how fat is incorporated, it may coat some of the starch granules, preventing them from absorbing water. This reduces the degree of gelatinization during baking, which in turn slows the rate of retrogradation.
• Fat’s hydrophobic (water repellent) properties help “trap” moisture in the dough, slowing moisture loss in the baked goods and, consequently, delaying retrogradation.

Even small amounts of fat, around 2-3% (in baker’s percentage), can significantly slow retrogradation.

Sugar Content in the Dough

Sugar, like fat, interferes with the starch molecules’ ability to revert to a crystalline structure and bind together, disrupting the retrogradation process.

Even a relatively small amount of sugar, up to 5% (in baker’s percentage), can effectively slow down retrogradation.

Storage Temperature

The storage temperature plays a crucial role in the rate of retrogradation.

At low temperatures above freezing (0°C/32°F), retrogradation accelerates due to chemical changes that promote the crystallization of starch molecules. This leads to the dough staling faster and losing its softness and freshness.

The “ideal” temperature for retrogradation to occur at the fastest rate is between 0-5°C (32-41°F), which is the standard refrigerator temperature.

In simple terms: storing baked goods in the fridge speeds up retrogradation, causing them to stale and lose their softness the fastest. Thus, refrigerating baked goods is the least favorable option, as it promotes rapid staling.

On the other hand, freezing baked goods at -18°C (0°F) or lower, halts the retrogradation process. At these temperatures, water molecules “lock” in place, effectively freezing the retrogradation process – quite literally. In other words: freezing halts the retrogradation process.

Storage Conditions (Humidity and Air Exposure)

Storing baked goods in a very dry environment, or exposing them to the air (uncovered), leads to greater moisture loss. As mentioned earlier, moisture content influences the rate of retrogradation, so faster drying will accelerate retrogradation.

On the other hand, storing baked goods in a less dry or even humid environment, as well as covering them or placing them in an airtight container to minimize air contact, will help slow down moisture loss, and consequently – slow down retrogradation.

Cooling Rate

Retrogradation is temperature-dependent: The faster the baked product cools, the faster retrogradation occurs.

For example, the structure and shape of baked goods directly influence the speed at which they cool:

• Large baked goods with significant volume, such as a large loaf of bread, will cool more slowly, and undergo slower retrogradation compared to smaller baked goods..
• Baked goods with a larger surface area-to-volume ratio, such as pita or flatbreads, will cool much faster, leading to faster retrogradation.

Later, we will discuss how the cooling rate specifically affects retrogradation in the context of pizza and bread.

Use of Dough Conditioners/Improvers

Some dough conditioners help slow down retrogradation and the staling of baked goods, allowing them to remain soft and fresh for longer. Among these are:

• Enzymes
• Emulsifiers
• Lipids
• Hydrocolloids
• Proteins

Enzymes

Enzymes are natural dough improvers. The primary group of enzymes that aid in slowing down retrogradation are amylase enzymes, which break down starch during fermentation and baking.

Amylase enzymes significantly affect the rate of retrogradation and are the most effective dough conditioners in this regard:

• Alpha-Amylase Enzymes (Short-Term Retrogradation): Adding alpha-amylase enzymes to the dough (by incorporating diastatic malt powder) increases the breakdown of starch chains – both amylopectin and amylose. This results in shorter starch chains, which reduces their ability to recrystallize and bond with each other, ultimately slowing down short-term retrogradation.
• Maltogenic Amylase Enzymes (Long-Term Retrogradation): These enzymes also break down starch, but their significant effect is on amylopectin. They have a unique mechanism that allows them to rearrange amylopectin molecules, significantly slowing down long-term retrogradation. 

In summary: using alpha-amylase enzymes contributes to a certain slowdown of short-term retrogradation, while maltogenic amylase enzymes significantly slow down long-term retrogradation.

Emulsifiers, Lipids, Hydrocolloids, and Proteins

All substances in this group share a similar mechanism of action, comprising one or more of the following effects:

1. Chemical or physicochemical disruption of the starch recrystallization process.
2. Retaining moisture (free water) in baked goods.

The action mechanism for each group of substances, along with examples of baking improvers, is as follows:

• Emulsifiers form complexes with starch molecules through hydrophobic or van der Waals bonds, preventing them from reorganizing and returning to their crystalline structure. These complexes interfere with the rearrangement of starch molecules, slowing down retrogradation.
  • Examples: DATEM (E472e), lecithin (E322), sodium stearyl lactylate (E481), mono- and diglycerides (E471).
• Lipids ‘coat’ starch molecules, preventing them from reorganizing and recrystallizing.
  • Example: Glycerin/Glycerol (E422) [also used as a humectant, a water-retaining agent].
• Hydrocolloids form gel networks that absorb water, aid in water retention and hinder starch recrystallization.
  • Examples: Guar gum (E412), xanthan gum (E415).
• Proteins contribute to water absorption, strengthen the gluten network, and create a more stable structure that reduces starch recrystallization.
  • Examples: Milk/Dried Milk Powder (milk proteins), eggs (egg proteins).

Using these substances helps retain the softness and freshness of baked goods, preventing staling and extending their shelf life.

Starch Retrogradation in Pizza: Why Pizza Becomes Tough Faster Than Bread

Pizza loses its softness quickly, becoming tough and chewy quickly after baking. This is due to several key differences between pizza and bread that accelerate retrogradation in pizza dough.

The main reasons why pizza undergo faster retrogradation than bread include:

• High baking temperatures.
• Flatter structure of pizza.
• Lower final moisture content.
• Faster cooling rate.

High Baking Temperature

Most pizza types, except for cracker-style pizzas, are baked at relatively high temperatures, ranging from 280°C/530°F for New York style pizza to 500°C/930°F for Neapolitan pizza. In contrast, most breads and baked goods are baked at temperatures between 170-240°C (340-465°F).

Higher baking temperatures accelerate gelatinization, which in turn speeds up retrogradation. As a result, the retrogradation process in pizza dough is faster compared to lower-temperature baked goods.

In summary: Pizza dough baked at higher temperatures experiences more gelatinization, leading to faster retrogradation.

Flatter Structure of Pizza

Pizza, as we know, is a flat baked product. This flatter structure results in:

• Higher crumb-to-crust ratio: Pizza has more crust than crumb.
• Higher surface area to volume ratio: A larger portion of the dough is exposed to heat during baking and to air after baking.

These characteristics contribute to:

• Greater moisture loss: Since pizza has more crust, and moisture loss during baking primarily occurs from the crust, it loses more moisture compared to other baked goods.
• Faster cooling: Due to its large surface area-to-volume ratio, pizza cools quickly after being removed from the oven. In contrast, a large loaf of bread takes much longer to cool completely.
• Slower crumb moisture loss: Baked goods with a thicker crumb, like a loaf of bread, retain moisture for a longer period, because moisture migration (which we will discuss later) occurs more gradually.

Lower Final Moisture Content in Pizza vs. Bread

A standard loaf of bread contains about 40% moisture at the end of baking, while pizza contains around 30%.

As higher moisture content slows down retrogradation, pizza, with its lower moisture content, undergoes retrogradation faster than bread.

Faster Cooling Rate

The flat shape of pizza, with minimal crumb and a higher surface area-to-volume ratio, results in faster cooling.

Since retrogradation accelerates with faster cooling, pizza dough undergoes rapid retrogradation.

The quick cooling of pizza is the primary reason pizza dough becomes tough and loses its softness quickly.

Reheating: “Reversing” Retrogradation

Reheating baked goods causes a partial reversal of the retrogradation process, temporarily restoring softness.

This happens through two main mechanisms during reheating:

1. Breaking the bonds between amylose molecules: Heat breaks the hydrogen bonds between amylose molecules, “unlocking” some of the amylose double helices formed during retrogradation. This makes the starch less crystalline and more amorphous, thereby softening the baked good.
2. Redistribution of moisture: Reheating causes the free water molecules in the baked product, some of which were expelled from the starch during retrogradation, to redistribute and be reabsorbed by the starch, resulting in softening. The more free water present, the more effectively this softening process occurs.

To effectively reverse retrogradation through reheating, two conditions must be met:

• Temperature: The baked good must reach the appropriate temperature range for re-gelatinization, and stay there long enough to break the crystalline structures – between 60-80°C (140-180°F) for amylose, and above 90°C (195°F) for amylopectin.
• Moisture: The baked good must contain sufficient moisture, specifically free water, to be redistributed and reabsorbed by the starch.

To restore maximum softness, it’s helpful to heat the baked good in a humid environment, or directly add moisture to it. Adding moisture during reheating allows the starch to “re-gelatinize” and regain its softness. This can be achieved by:

• Actively adding moisture (spraying/wetting): Spraying the baked good with water or wetting it before reheating.
• Heating in a sealed vessel: Heating the baked good in a pan or vessel with a closed lid to trap the steam generated during reheating.

2. Moisture Migration

From the moment a baked good comes out of the oven, moisture migration begins. This process affects pizza significantly after baking.

Moisture naturally moves from areas of high concentration to areas of lower concentration, until equilibrium is reached. In baked goods, moisture migrates from the crumb (which contains more moisture) to the crust (which contains less).

Moisture migration from the crumb to the crust has two main effects on pizza:

• Effect on the crust (loss of crispness): The crust absorbs moisture, becomes “wetter”, and loses its crispiness.
• Effect on the crumb (moisture loss and faster retrogradation): The crumb rapidly loses moisture – moisture that has migrated to the crust – accelerating retrogradation.

The Effect of Moisture Migration on the Crust: Loss of Crispiness

As soon as the pizza comes out of the oven, moisture begins migrating to the crust. This moisture softens the crust, causing it to lose its crispiness and become spongy, soggy, and leathery.

In general, thinner crusts are more “vulnerable” to moisture migration, leading to a quicker loss of crispiness. Conversely, thicker crusts are more “resistant,” allowing them to maintain crispiness for a longer period. Pizzas with high-moisture toppings also experience faster moisture migration to the crust, further accelerating the loss of crispiness. For more on this topic, see The Complete Guide to Crispy Pizza: All the Ways to Create a Crispier Crust.

The Effect of Moisture Migration on the Crumb: Moisture Loss and Accelerated Retrogradation

Moisture migration from the crumb to the crust naturally reduces the moisture content in the crumb. As previously mentioned, the less moisture (free water) present in the crumb, the faster retrogradation occurs.

In the case of pizza, where moisture migrates quickly from the crumb to the crust, this leads to accelerated retrogradation in the crumb, and a rapid toughening and loss of softness.

3. Changes in Gluten Structure

From the moment the baked good leaves the oven and begins to cool, several changes occur in the structure of the gluten network, contributing to toughening:

• Stabilization and ‘shrinkage’: The gluten network, which is flexible and elastic during baking, loses its elasticity as the temperature drops. The gluten-forming proteins – glutenin and gliadin – reorganize into a denser, more compact structure, making the gluten network more rigid and less elastic.
• Release of free water: As the gluten network becomes more compact, some of the free water trapped within it is expelled, leading to a drier and stiffer texture.
• Interactions within the gluten network: As the baked good cools, various chemical bonds between the gluten-forming proteins strengthen, primarily hydrogen bonds. These bonds cause the gluten network to become firmer, less elastic, and more rigid.

In summary: As a baked good cools, the gluten network contracts and stabilizes, releasing free water, and becomes stiffer and drier. This process, along with the retrogradation of starch, causes the baked good to lose its elasticity and become tougher, developing a more leathery texture.

Generally, the higher the protein content in the flour, the tougher and chewier the baked good will be, both when fresh and as it cools.

This is particularly true for pizza – dough made from flour with a higher protein content has a stronger, “denser” gluten structure (due to more gluten bonds formed), “amplifying” the phenomena described above, and creating a tougher, more leathery texture upon cooling.

How to Reduce Toughening of Pizza When It Cools and Maintain Softness for Longer: Practical Tips

Now that we understand the processes that cause baked goods to become tough and lose their softness, let’s explore ways to reduce this and keep them – specifically pizza – soft and ‘fresh’ for longer.

Adding Fat to the Dough

Adding any type of fat to the dough (oil, butter, shortening etc.) slows retrogradation, delays crumb toughening, and helps maintain a soft, tender texture for longer. Even a small amount, around 1–2% (in baker’s percentage), can significantly delay toughening.

Adding fat is the simplest, most effective, and most ‘natural’ method to ensure a pizza that retains its softness for longer.

In the video below, you can see three Neapolitan pizzas, all made from the same dough, using the exact same process, 10 minutes after baking. The only difference is the amount of oil in the dough. The tested oil amounts are:

• 0% (the first marinara pizza)
• 3% (the second pizza)
• 6% (the third pizza)

As you can see, adding oil significantly impacts the dough’s ability to retain softness. Just 10 minutes after baking, the first pizza had already lost its softness and turned tough, while the pizzas containing oil remained noticeably softer. Even at just 3% oil, the effect was clear and significant.

In summary: adding fat to the dough, even in small amounts of 1–2%, helps slow retrogradation and preserve softness for longer.

Adding Sugar to the Dough

Sugar, like oil, helps slow down retrogradation. Even a small amount of 1–2% sugar (in baker’s percentage) can reduce the dough’s toughening and loss of softness to some extent. The higher the sugar content, the more pronounced its effect on delaying retrogradation.

In summary: Adding sugar to the dough, even in small amounts, helps slow down retrogradation and keeps the pizza softer for longer.

Baking at a Lower Temperature

The higher the baking temperature, the more gelatinization occurs during baking, leading to increased amylose leakage into the dough. This accelerates retrogradation, causing the dough to harden and lose its softness more quickly.

Thus, baking at a lower temperature (which naturally extends the baking time) helps delay retrogradation, slowing down the toughening process and preserving the baked good’s softness for longer. The lower the baking temperature, the slower retrogradation will occur.

In summary: Baking at a lower temperature will help slow down retrogradation and retain the softness of the pizza for a longer time.

Using Lower Protein Flour

The higher the protein content in flour, the tougher and chewier the pizza will be – both when fresh and after it has cooled.

High(er) protein flour creates a stronger gluten network, which undergoes more pronounced structural changes as the pizza cools, leading to a firmer, chewier texture.

In summary: Using flour with lower protein content helps minimize gluten-related toughening as the pizza cools, resulting in a softer, more tender texture that lasts longer.

A More Extensible, Less Elastic Dough

Dough that is more extensible and less elastic produceses a softer, more tender texture after baking. A highly elastic and strong gluten structure contributes to a chewier, tougher bite, both when fresh – and especially as the pizza cools.

In summary: Dough with greater extensibility and lower elasticity undergoes less dramatic changes in gluten structure after baking, resulting in a pizza that remains softer and less leathery as it cools.

Higher Moisture Content (Dough Hydration)

The more water, particularly free water, present in the dough, the slower the retrogradation process becomes.

This means that using higher dough hydration can help delay retrogradation to some extent, preserving the dough’s initial softness.

In summary: Higher dough hydration slows down retrogradation, helping the baked product retain its softness for a longer time.

Using Dough Conditioners/Improvers

Baking conditioners generally help slow down long-term retrogradation, making them more effective for breads or other baked goods that are stored and consumed later. For pizza, which is typically eaten right away, the impact of dough conditioners on retrogradation is limited.

That said, for pizza, which undergoes rapid retrogradation, the only dough improver that can help slow down retrogradation in the short term is diastatic malt powder, due to its active alpha-amylase enzymes.

Proper Storage

To minimize retrogradation, it is crucial to store baked goods correctly. This applies to any baked goods containing flour (starch).

First, avoid storing baked goods in the fridge. The temperature in the fridge (about 4°C/40°F) is where retrogradation occurs at the fastest rate.

Simply put, storing baked products in the fridge will significantly accelerate retrogradation, causing them to stale and lose their softness and freshness quickly.

To slow down retrogradation effectively, follow these storage guidelines:

1. Very Short-Term Storage (Minutes to Hours): If you need to keep a baked or reheated pizza warm for a short period (from minutes up to a few hours), you can leave it in an oven set to 60°C (140°F) using a conventional baking setting (no convection). At this temperature, retrogradation is prevented, allowing the pizza to maintain its texture until served.

2. Short-Term Storage (Hours to 1 Day): For short-term storage (such as keeping leftovers for the next day), place the pizza in an airtight container or wrap it in a plastic bag to minimize moisture loss. Store it at room temperature, ideally between 20-25°C (68-77°F). When ready to eat, reheat the pizza as usual or enjoy it at room temperature.

3. Long-Term Storage (2 Days or More): For long-term storage, wrap individual slices (or a whole pizza) tightly in plastic wrap and place them in the freezer. The freezer temperature prevents retrogradation, ensuring the pizza/baked good keeps best over time.

For the best results, transfer the pizza to the freezer as soon as possible after it has completely cooled. Freezing halts further retrogradation, but does not reverse any retrogradation that has already occurred since the baked good was removed from the oven.

In summary: To best preserve the freshness of baked goods, cover and store them at room temperature for short-term use, or freeze for long-term use. Avoid storing baked goods in the fridge, as this will cause them to stale the fastest.

Reheating

This section is somewhat different, because reheating does not slow down retrogradation; instead, it reverses it, allowing the baked good to regain its softness.

As mentioned, two conditions must be met to restore softness to the baked good during reheating:

1. A sufficiently high temperature that can break down the crystalline structure of the retrograded starch – above 60°C (140°F) for amylose, and above approximately 90°C (195°F) for amylopectin.
2. The baked good and/or the environment in which it is reheated must contain enough moisture to redistribute within the baked good and be reabsorbed by the starch.

Reheating Methods [Including Practical Tips]

There are many ways to reheat baked goods, and the specific heating method depends on several factors:

• The type of baked good (the shape and its desired eating characteristics).
• How stale/fresh it is (the degree of retrogradation it has already undergone).
• The desired end result (for example, restoring crispiness as well as softness).

Reheating in the Microwave

The microwave is one of the easiest and most convenient reheating methods, and it is highly effective in reversing retrogradation and restoring softness to baked goods. It works particularly well for items that are meant to be very soft with no crisipness, such as pita bread, hamburger buns, and even Neapolitan pizza.

However, proper usage is crucial. Overheating in the microwave can make baked goods excessively soft, spongy, or “mushy,” which then quickly turns tough once cooled.

Guidelines for Effectively Using the Microwave for Reheating

Microwave heating can cause baked goods to become tough and leathery more quickly than other methods due to two main factors:

• Uneven heating: Microwave waves heat water molecules unevenly, causing some areas to heat up rapidly, while others remain cooler. This is why food often has hot and cold spots after microwaving.
• Intense and rapid heating: The microwave’s intensity accelerates moisture evaporation, especially in the hotter areas. Some parts of the baked good may dry out while others stay moist. Additionally, excessive localized heat can cause starch and gluten to overheat, leading to a leathery texture.

The combination of uneven heating and rapid moisture loss increases the likelihood of baked goods becoming tough once cooled. While this doesn’t always happen, it is more likely if heating is not done carefully, such as microwaving for too long, or reheating baked goods with irregular shapes that prevent even heat distribution.

To achieve the best results when reheating baked goods in the microwave, follow these guidelines:

• Use medium-low power (40-60%): Lower power settings allow for more even reheating.
• Add moisture if needed: If the baked good has become particularly tough or ‘dry’ due to advanced retrogradation, lightly spray it with water before reheating, or drizzle a small amount of water over it. Alternatively, wrap it in a clean, unscented kitchen towel or microwave-safe plastic wrap to help retain moisture generated during reheating.
• Heat in short pulses: Microwave in short pulses of 10-20 seconds, checking frequently. Even a few extra seconds can mean the difference between perfectly reheated and overheated baked goods.
• Use the microwave as a preheater (see next section): a brief preheating in the microwave can be used to partially-soften the baked good before finishing the reheating with another method.

Using the Microwave to “Preheat”

Microwave heating is most effective as a “preheater” when combined with other reheating methods. A brief microwave session of up to 30 seconds, depending on the baked good’s size and shape, helps partially heat and soften it before transferring it to another heating device for final reheating.

After preheating in the microwave, completing the process with a different method provides three key benefits:

• Shorter overall reheating time.
• More even reheating, preventing inconsistencies in softness and eliminating hot or cold spots.
• Restored crispiness, if desired, by using a method better suited for restoring crispiness.

Reheating in a Toaster (Press or Pop-Up Toaster)

A toaster is a good option for reheating, but without careful monitoring, it can cause the outside of the baked good to dry out and become crispier or drier than desired.

Toasters are naturally best suited for reheating bread slices or other flat baked goods, as other non-flat baked goods do not reheat well in them, or even fit without being squashed and flattened.

To reheat in a toaster, simply place the slice inside, even if frozen. It’s essential to monitor the heating process to prevent excessive drying.

A press toaster offers an additional advantage: by pressing the slice, it helps “trap” moisture inside, optimizing both heating and moisture retention, thus effectively reversing retrogradation.

Heating in a Pan with a Lid on Over the Stove

This method works well for reheating slices of bread or flatbreads. The lid traps moisture inside the pan, which helps reverse retrogradation effectively.

Adding a small amount of water to the pan can also help, as the evaporating water creates additional steam, especially if the baked good has become very tough. However, this step isn’t required, and care should be taken not to over-soak the reheated item.

It’s important to monitor the flame’s (or heating element) intensity. A flame that’s too strong can cause the part of the baked good in contact with the pan to dry out or burn. In most cases, a medium flame is recommended.

To ensure even heating, turn the reheated item after one or two minutes.

Reheating in the Oven

An oven radiates heat evenly to all parts of the baked good being reheated, making it ideal for large-volume pastries, multiple baked goods at once, or items that need to retain their shape, such as loaves (or slices) of bread, rolls, buns, and puff pastries.

For optimal results, preheat the oven to 150-180°C (300-360°F) using a conventional baking setting (top and bottom heat, no convection). This temperature range allows the starch in the crumb to re-gelatinize, without burning or excessively drying out the crust.

Typically, heating for 5-10 minutes (depending on the type and volume of the baked good) should be sufficient, provided the oven is properly preheated.

Soft, non-crispy baked goods like babkas, brioche, soft rolls (e.g., hamburger buns), or pita bread can be wrapped in foil to trap moisture during heating, or sprayed with water before reheating.

Using Convection Mode to Restore Crispiness

Convection mode circulates hot air in the oven (through forced convection), resulting in uniform heat distribution. One major side effect of using convection mode is the drying of the food being heated, making it particularly effective for restoring crispiness to baked goods.

Using convection mode works great for items such as puff pastries, or any baked good where you want to accentuate or restore crispiness.

When using convection mode to reheat baked goods, it is recommended they be at room temperature or preheated in the microwave.

Reheating frozen baked goods in convection mode may result in uneven heating, causing the exterior to dry out before the inside is properly heated. It is recommended to monitor the reheated item to prevent excessive drying.

A great technique for restoring crispiness is to turn on convection mode during the last minute or two of reheating, once the reheated item is mostly warmed. This ensures the reheated item gets a boost of crispiness, without risking over-drying or uneven heating.

Reheating in an Air Fryer

An air fryer operates on the same principle as convection mode in the oven – circulating hot air (forced convection). Therefore, everything mentioned in the previous section about using convection mode also applies when using an air fryer for reheating.