How to Make Fermented Mayo

Fermented mayonnaise is a probiotic-enhanced version of the classic emulsion. Fermentation adds tang, extends shelf life, and introduces beneficial bacteria to this versatile condiment.

Category: Condiments & Sauces · Method: Lactic Acid · Time: 3-7d · Difficulty: 2/5 · Yield: varies · Temp: 18-22°C

History

Mayonnaise originated in 18th century France. Fermenting mayo is a modern adaptation that draws from traditional preservation techniques while creating a healthier, more flavorful spread.

Ingredients

  • 2 large Egg yolks — Pasteurized eggs are highly recommended for safety when fermenting at room temperature; ensure they are at room temperature before starting.
  • 1 cup Olive or avocado oil — Light-flavored; avoid extra virgin olive oil as the high-speed blending can make it taste bitter.
  • 1 tbsp Lemon juice — Fresh
  • 1 tsp Dijon mustard — Acts as a primary emulsifier and adds depth.
  • 1/2 tsp Sea salt — Non-iodized salt is best for fermentation.
  • 1 tbsp Whey or brine — Must be raw/unpasteurized (from yogurt or fermented pickles) to provide the necessary Lactobacillus cultures.

Equipment

  • Immersion blender or food processor
  • Tall narrow jar
  • Mixing bowl

Instructions

  1. Combine base

    Place yolks, lemon juice, mustard, and salt in a tall, narrow jar that just fits the head of your immersion blender.

    Time: 2 min

  2. Emulsify

    Pour the oil on top of the other ingredients. Place the immersion blender at the very bottom of the jar. Turn it on high and keep it firmly at the bottom without moving it until a thick white emulsion forms at the base. Once the bottom third is emulsified, slowly tilt and pull the blender upward to incorporate the remaining oil.

    Time: 5 min

    Tip: If the emulsion doesn't start within 15 seconds, stop and check your positioning.

  3. Add starter

    Gently fold in the whey or vegetable brine using a spatula until fully incorporated. This introduces the bacteria that will preserve the mayo.

    Time: 2 min

  4. Ferment

    Cover the jar loosely with a lid or cloth. Leave at room temperature (18-22°C) for 7 to 12 hours. This allows the lactic acid bacteria to proliferate, lowering the pH and creating a stable, probiotic environment.

    Time: 7-12 hours

    Tip: Do not exceed 12 hours at room temperature to prevent the oils from oxidizing or the eggs from spoiling.

  5. Refrigerate

    Tighten the lid and transfer to the refrigerator. The mayo will thicken further as it chills.

    Time: 5 min

Fermentation Timeline

  • Hour 1-4: Fermentation begins — Bacteria start multiplying.
  • Hour 5-8: Tangy development — Slight sourness develops.
  • After 8 hours: Ready — Fermented mayo with enhanced flavor.

Signs of Success & Spoilage

Good signs

  • Slight tang
  • Creamy texture maintained
  • Fresh aroma
  • Stable emulsion

Warning signs

  • Broken emulsion
  • Off-odors
  • Unusual colors
  • Excessive sourness

Troubleshooting

Mayo broke
Cause: Oil added too fast Solution: Start over, add oil very slowly.
Too sour
Cause: Over-fermented Solution: Reduce fermentation time next time.
Too thin
Cause: Excess liquid Solution: Use less whey or lemon juice.

Storage

Refrigerator in a sealed glass jar Keeps 1-2 months. The fermentation process significantly extends the shelf life compared to fresh mayo (which lasts 1-2 weeks). Always use a clean spoon to avoid introducing mold-causing bacteria.

Health Benefits

  • Probiotics
  • Healthy fats from quality oil
  • Choline from egg yolks
  • Enhanced nutrient absorption

Serving Suggestions

  • In sandwiches and wraps
  • As base for aioli
  • In potato salad
  • For dipping vegetables
  • In deviled eggs

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Authoritative food-safety sources

This site cross-references but does not replace professional guidance. For canonical, peer-reviewed fermentation safety information, consult:

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