# Why Does My Mayonnaise Break? Find the Exact Oil Limit for Any Emulsifier
If you have ever asked yourself "why did my mayonnaise split?" or "how much oil can I add before my aioli breaks?", the answer lies in a single number: the oil volume fraction. Every emulsion - whether a classic French mayonnaise, a garlicky aioli, a creamy vinaigrette, or a modernist foam - can only hold a finite amount of oil before it collapses. Our emulsion stability calculator tells you exactly where that breaking point is, based on your specific emulsifier, water phase, and oil volume. No more guessing, no more wasted ingredients. 78% Egg Yolk Max Oil
85% Polysorbate Limit
74% Theoretical Packing
15 ml Yolk Water Content
- You are adding oil too fast - Speed is rarely the real cause. If your oil fraction stays below the emulsifier limit, the emulsion will hold regardless of pouring speed.
- Your ingredients are too cold - Cold eggs or cold oil increase viscosity and make droplet formation harder. Always bring ingredients to room temperature.
- You exceeded the oil limit for your emulsifier - Each emulsifier has a maximum packing fraction. Egg yolk caps at 78% oil, mustard at 70%, soy lecithin at 82%, and polysorbate at 85%.
- Your water phase is too small - Without enough water to surround the oil droplets, they have nowhere to go but into each other. The calculator below tells you exactly how much water you need.
# Which Emulsifier Should You Use? A Practical Comparison
Choosing the right emulsifier depends on your recipe, flavor profile, and desired oil capacity. Here is how the four most common culinary emulsifiers stack up against each other in real kitchen conditions.Egg Yolk
Advantages
- Highest flavor compatibility for classic sauces
- Contains both lecithin and lipoproteins for robust emulsions
- Adds natural color and richness
- Works with up to 78% oil fraction
Disadvantages
- Adds cholesterol and egg flavor
- Requires careful temperature control
- Not suitable for vegan preparations
- Limited to about 15 ml water contribution per yolk
Mustard
Advantages
- Adds tangy flavor and complexity to dressings
- Widely available and easy to use
- Works well at room temperature
- Ideal for quick vinaigrettes
Disadvantages
- Lower max oil capacity (70%)
- Weaker emulsifying power than egg yolk
- Flavor may conflict with delicate sauces
- Not suitable for neutral-tasting emulsions
Soy Lecithin
Advantages
- High oil tolerance (82%) for stable sauces
- Neutral taste does not alter recipes
- Plant-based and vegan friendly
- Works with small water volumes
Disadvantages
- Requires precise weighing
- Less forgiving than egg yolk
- Not a pantry staple for most home cooks
- Can create a slightly artificial texture
Polysorbate
Advantages
- Highest oil capacity of any emulsifier (85%)
- Creates ultra-stable foams and airs
- Works with minimal water phase
- Ideal for modernist and experimental cuisine
Disadvantages
- Synthetic additive, not natural
- Hard to source for home kitchens
- Requires scale for accurate dosing
- Overpowering if used in excess
Egg Yolk
The classic mayonnaise emulsifier. Contains lecithin and lipoproteins.
- Max oil: 78%
- ~15 ml water per yolk
- Adds richness and color
- Best for mayo and aioli
Mustard
Relies on mucilage and seed proteins. Adds tangy flavor.
- Max oil: 70%
- ~10 ml water content
- Weaker emulsifying power
- Ideal for vinaigrettes
Soy Lecithin
Highly concentrated plant-based surfactant.
- Max oil: 82%
- ~5 ml water content
- Neutral taste profile
- Modernist cuisine staple
Polysorbate
Synthetic emulsifier with maximum surfactant capacity.
- Max oil: 85%
- ~2 ml water content
- Highest oil tolerance
- Used in foams and airs
| Emulsifier | Max Oil % | Oil per 100 ml Water | Best Use Case |
|---|---|---|---|
| Egg Yolk | 78% | ~355 ml | Mayonnaise, aioli, hollandaise |
| Mustard | 70% | ~233 ml | Vinaigrettes, light dressings |
| Soy Lecithin | 82% | ~456 ml | Modernist sauces, foams |
| Polysorbate | 85% | ~567 ml | Stable foams, experimental cuisine |
# The Science: Why Emulsions Break and How Kepler's Conjecture Applies to Your Kitchen
A culinary emulsion works by dispersing tiny oil droplets throughout a continuous water phase. Emulsifiers - such as the lecithin in egg yolk, the mucilage in mustard, or synthetic surfactants like polysorbate - coat each droplet and prevent it from merging with its neighbors. The science behind this is pure geometry: oil droplets behave like tiny spheres packed together in a confined space.The maximum volume of spheres you can fit into a given space - known as Kepler's conjecture - is about 74%. In real kitchen systems, powerful emulsifiers stretch this limit to 80-85%, but beyond that point, the droplets are squeezed so tightly they merge, and the emulsion collapses instantly. This is not a gradual process: it happens in a split second, turning a silky sauce into a pool of grease.# How to Rescue a Broken Emulsion Step by Step
If your mayonnaise or sauce has already split, do not throw it away. The fix is straightforward - but only if you understand the phase ratio. Blending harder won't help; you need to add more of the continuous (water) phase. Our calculator tells you exactly how much water or how many additional egg yolks you need to restore balance.3 Signs Your Emulsion Is About to Break
Watch for thickening followed by sudden thinning as the first warning. Then look for a glossy surface turning grainy or visible oil pooling at the edges of the bowl. If you see any of these signs, stop adding oil immediately and whisk in a teaspoon of cold water before continuing.
# Practical Tips for Perfect Emulsions Every Time
The golden rule: The ratio of oil to water matters more than technique, temperature, or speed. Use our calculator to find your exact oil limit before you start whisking.
Temperature Matters
All ingredients should be at room temperature. Cold eggs or cold oil dramatically increase the risk of breaking. Take ingredients out of the fridge 30 minutes before starting.The Water Safety Net
If your recipe doesn't include enough acid (vinegar, lemon juice), add one teaspoon of cold water per egg yolk before you start adding oil. This extra water creates a wider safety margin and makes your emulsion more forgiving.Fix a Broken Batch
Put a fresh egg yolk in a clean bowl. Whisk it with a teaspoon of water. Then, drizzle the broken mixture in as slowly as possible, exactly as if it were raw oil. Once it re-emulsifies, you can add the rest faster.# Culinary Emulsion Glossary
- Continuous Phase
- The liquid that surrounds the droplets - usually water, vinegar, or citrus juice in oil-in-water emulsions like mayonnaise.
- Dispersed Phase
- The liquid broken into tiny droplets - oil in most culinary emulsions. The more you add, the closer the droplets pack together.
- Volume Fraction
- The ratio of oil volume to total volume. At about 74-85% (depending on emulsifier), the emulsion reaches its geometric breaking point.
- Coalescence
- When two or more oil droplets merge into a larger one. This is the microscopic process that triggers a visible emulsion break.
- Phase Inversion
- The point where an oil-in-water emulsion flips to water-in-oil - as happens when making butter from cream. This is the ultimate failure mode.
Key Takeaways for Stable Emulsions
Each emulsifier has a maximum oil fraction: egg yolk 78%, mustard 70%, soy lecithin 82%, polysorbate 85%.
The breaking point is determined by geometry (Kepler's conjecture at 74%), not by mixing speed.
Always start with room temperature ingredients and add a small amount of water as a safety buffer.
A broken emulsion can be rescued by adding fresh emulsifier and more water phase, not by blending harder.
Use our emulsion stability calculator above to get the exact oil limit for your specific ingredients.