Foolproof Mayonnaise Recipe

Make sure all liquid ingredients (oil, milk, mustard, and lemon juice/vinegar) are very cold. Refrigerate them for a few hours or briefly in the freezer to ensure the heat doesn't spoil the emulsion.

If using an immersion blender (stick blender), add all liquid ingredients and other components (except the oil, if you prefer) to the container, then add the oil all at once, without needing to drizzle it in a thin stream.

If using a standard blender, place all ingredients except the oil in the jar, ensuring the mixture completely covers the blade assembly. If necessary, supplement with very cold water (prepared with ice cubes) until the level covers the blades.

If you are unsure about the emulsion, add about 1/4 of a cooked potato to the blender. The starch will help thicken the sauce and may allow you to use slightly less oil.

With the blender or immersion blender running, begin incorporating the cold oil. Start by pouring it in a thin stream (if using a standard blender) until the emulsion forms. If you used an immersion blender, the oil may have been added in Step 2.

When the mayonnaise reaches the desired consistency and the sound of blending changes, indicating full emulsification, add salt, pepper, and any other desired spices or fresh herbs for seasoning.