Skip to Content

What does gelatin do in marshmallows?

Gelatin is a key ingredient that gives marshmallows their soft, fluffy texture. It acts as a stabilizer and emulsifier to help whipped air bubbles stay suspended evenly throughout the marshmallow. Without gelatin, marshmallows would simply be a sticky syrup.

The Role of Gelatin

Gelatin allows marshmallows to achieve their characteristic light and airy texture in several ways:

  • Foaming agent – Gelatin helps unfold proteins to create foam when ingredients are whipped. This incorporates tiny air bubbles into the marshmallow mixture.
  • Emulsifier – Gelatin stabilizes fat molecules and prevents them from separating out. This results in a smooth, uniform texture.
  • Gelling agent – When cooled, gelatin sets the marshmallow into a soft solid that holds its shape. It creates a 3D matrix that traps air bubbles.
  • Moisturizer – Gelatin binds water, keeping marshmallows soft and preventing them from drying out.

Without gelatin, it would be impossible to achieve the light, fluffy aerated texture that gives marshmallows their appeal. The whipped syrup would simply deflate into a sticky mess.

How Gelatin Works on a Molecular Level

On a molecular level, gelatin is a hydrocolloid – compounds that have the ability to form gels when dispersed in water. It is derived from collagen, the main structural protein found in animal connective tissues and bones.

Chemically, gelatin is made up of long chains of amino acids such as glycine, proline, and hydroxyproline. Under hot water, the triple-helix structure of collagen unravels into individual protein strands. When cooled, these strands form weak bonds with water molecules and re-associate with other strands to create a 3-dimensional meshwork.

This meshwork exhibits viscoelasticity – it acts like an elastic solid but flows like a viscous liquid when force is applied. This allows hot gelatin to be poured and whipped into marshmallow batter. Upon cooling, it coagulates into a soft, pliable gel that holds air bubbles in suspension.

Key Properties of Gelatin

  • Thermo-reversible – Gelatin melts when heated and sets into a gel again upon cooling. This allows marshmallows to be scooped or cut when warm.
  • Adhesive – Gelatin forms bonds between water, air bubbles, sugars, and other ingredients to provide structure.
  • Surface-active – Gelatin reduces surface tension, enabling foaming and emulsification.
  • Film-forming – Gelatin forms a pliable film when it sets, giving marshmallows an outer skin.

These unique properties make gelatin an ideal gelling and foaming agent for achieving light, uniform, and stable marshmallow textures.

Typical Gelatin Content in Marshmallows

Most marshmallow recipes call for:

  • 1 tablespoon (about 3 packets) of gelatin per 1 cup of cold water
  • 2-3 cups of granulated sugar
  • 1/4 cup water + 1/4 cup light corn syrup for the sugar syrup
  • A pinch of salt
  • 1 teaspoon vanilla extract
  • 1/4 cup confectioners’ sugar for dusting

So in a standard recipe, gelatin makes up about 5-10% by weight. But the exact amount can vary depending on factors like:

  • The bloom strength of gelatin used – Higher blooms form firmer gels.
  • Eggs or egg whites – These strengthen the protein network.
  • Acids like cream of tartar – Acids weaken gelatin’s gelling power.
  • Fats like oil or shortening – These interfere with gelling.

Regardless of the ratio, gelatin must reach a critical concentration threshold to properly set the marshmallow mixture.

How Gelatin Interacts with Other Ingredients

In marshmallows, gelatin interacts with other components as follows:


Sugar is hygroscopic – it competes with gelatin for water. So using sufficient water is crucial to ensure all the gelatin dissolves and hydrates properly. The corn syrup also provides moisture.

Egg Whites

Some recipes call for beaten egg whites. When whipped, the egg foam reinforces the air bubbles stabilized by gelatin. Egg proteins complement gelatin, allowing less to be used.


A small amount of acid like cream of tartar weakens and inhibits gelatin from gelling too firmly. This creates marshmallow’s signature softness.


Common flavorings like vanilla extract, chocolate, peanut butter, or fruit purees are dispersed evenly in the gelatin-sugar matrix. Oil-based flavors may need an emulsifier like lecithin.


Small amounts of butter or oil can be incorporated but excess fat coats gelatin strands and prevents them from gelling properly. So recipes rarely call for more than a tablespoon.

Setting and Stabilizing the Marshmallow

Marshmallows undergo 3 main steps where gelatin plays a key functional role:

  1. Hydration – Gelatin powder is bloomed in cold water which allows strands to absorb liquid and swell.
  2. Aeration – Gelatin unfolds to maximize foaming and emulsification as ingredients are whipped into foam.
  3. Setting – On cooling, gelatin causes the foam to set into a stable semi-solid gel that retains moisture.

Without gelatin, marshmallow syrup would simply liquefy on heating or solidify into a hard candy at room temperature. Proper gelatin content and processing is essential.

Role of Gelatin in Other Marshmallow Types

The same principles apply to variations like:

  • Vegan marshmallows – Replace gelatin with gums like agar or pectin, or starches like tapioca.
  • Flavored marshmallows – Disperse flavor oils in gelatin-sugar matrix.
  • Colored marshmallows – Evenly mix liquid colors into gelatin foam.
  • Marshmallow crème – Omit setting step by increasing cornstarch to stabilize foam.

Regardless of type, aeration and stabilization remain critical to marshmallow texture.

What Happens When Gelatin is Omitted or Reduced

Without adequate gelatin, marshmallows will turn out poorly with the following effects:

  • Runny syrup that refuses to thicken or set
  • Foam that deflates into a puddle rather than mounding
  • Weak structure that collapses when cut or removed from pan
  • Stickiness due to syrup oozing out instead of being contained in gel
  • Dense, rubbery texture rather than a light, aerated feel
  • Liquid separating out rather than emulsifying into the foamed sugar

Reducing gelatin requires compensating with other ingredients and closely controlling cooking temperatures and times. Even minor issues with preparation or ingredients can ruin the marshmallow.

Health and Dietary Concerns with Gelatin

Gelatin is largely protein but contains little to no fat, carbs, or sugar. However, it raises some health and dietary concerns:

  • Allergies – Some may be sensitive or allergic to gelatin.
  • Religious restrictions – Gelatin is avoided by certain faiths and vegetarians.
  • Mad cow disease – Tiny risk from cattle-derived gelatin.
  • Artificial colors/flavors – Often added to colored or flavored marshmallows.

Veggie-based substitutes can be used to accommodate some dietary restrictions. Proper ingredient labeling allows consumers to make informed choices.

Difference Between Marshmallows Made with Gelatin and Vegan Versions

Vegan marshmallows swap out animal-based gelatin for plant-based stabilizers like:

  • Agar agar – Derived from seaweed.
  • Pectin – Found naturally in fruits.
  • Gums – Exudates from trees and plants.
  • Starches – From corn, tapioca, arrowroot.

This imparts some key differences in texture and performance:

Gelatin Marshmallows Vegan Marshmallows
Light, fluffy, excellent hold Slightly dense, less stability
Melts completely when warm Can become sticky when warm
Made from animal collagen Made from vegan alternatives

With careful formulation and processing, vegan versions can mimic the mouthfeel of gelatin marshmallows quite closely. But small differences remain detectable.

Common Questions About Gelatin in Marshmallows

Is gelatin necessary for making marshmallows?

Yes, gelatin is essential for achieving the characteristic soft, foamy, aerated texture of marshmallows. It stabilizes the whipped sugar syrup and allows it to set into a uniformly smooth gel.

Are marshmallows vegan?

Traditional marshmallows are not vegan because they contain gelatin derived from animal bones and tissues. However, vegan versions can be made using agar, pectin, gums, or starches as an alternative stabilizing agent.

Is it possible to make marshmallows without gelatin?

Yes, gelatin-free marshmallows can be made by substituting agar flakes, pectin, guar gum, xanthan gum, locust bean gum, or starches like tapioca or cornstarch. However, the texture is slightly different from gelatin versions.

What can be used to replace gelatin in making marshmallows?

Common gelatin substitutes include agar-agar, pectin, guar gum, xanthan gum, locust bean gum, carrageenan, and starches such as tapioca starch or cornstarch. Combinations work better than any single substitute.

Can I reduce the amount of gelatin in a marshmallow recipe?

It’s tricky but possible to reduce gelatin slightly by up to 1/4 of the amount specified. Any more than that and the marshmallow will likely fail to set properly. Boosting foam strength by adding egg whites can help compensate.

Do jet-puffed marshmallows contain gelatin?

Yes, all regular jet-puffed marshmallows contain gelatin. However, some major brands now offer alternative vegan versions made with agar, tapioca starch, and gums instead of gelatin.


Gelatin performs several essential functions in marshmallows. It enables foaming and emulsification, forms a stable gel matrix that holds moisture and shape, and allows the sugar syrup to transform into a light, fluffy foam. Alternatives like agar and pectin can mimic the mouthfeel but small textural differences remain. Understanding gelatin’s unique properties helps create marshmallows with an ideal soft, stable texture.