Step 1: Gather your ingredients and equipment. Ensure the egg is at room temperature for best emulsification.
Step 2: In your blender or food processor, combine the egg, distilled white vinegar, lemon juice, Dijon mustard, and salt. Blend on medium speed for about 10 seconds until well combined.
Step 3: With the blender running on low speed, very slowly drizzle in the vegetable oil to form the emulsion. Start with a few drops and gradually increase to a thin stream.
Step 4: Continue blending until the mayonnaise thickens, usually taking about 30 seconds to 1 minute. If too thick, add a teaspoon of water to loosen.
Step 5: Taste and adjust seasoning with more salt, vinegar, or lemon juice if desired.
Step 6: Transfer to a clean storage container with a lid. Store in the refrigerator for up to one week.
