Making homemade mayonnaise in food processor is a whole lot easier than whisking the components together in a bowl until they emulsify. But there's just one problem: Because the success of making mayonnaise in the food processor depends on having enough volume in the bowl—and that can vary, depending on the shape of the bowl—there is always a chance that mayonnaise will not form a proper emulsion. We came up with an easy way to fix it if it doesn’t.
Transfer mayonnaise mixture to 2-cup liquid measuring cup. Place 4 teaspoons water in bowl and, while whisking vigorously, very slowly drizzle in about ½cup mayonnaise mixture (consistency should resemble heavy cream). Transfer to a food processor and slowly drizzle in remaining mayonnaise. Once all mayonnaise has been added, scrape bottom and sides of bowl and process for 5seconds. (Consistency will be slightly looser than unbroken mayonnaise but still thick and creamy.)
