EMULSION

The Science of Mayonnaise: Oil and water don’t mix! You’ve heard it a thousand times and probably seen it for yourself. Truth is that we are surrounded by foods that are made by mixing oil and water. Mayonnaise, salad dressing, butter, ice cream, and milk are all oil-water mixtures that don’t separate under normal conditions. So how can we explain this?

An emulsion is a colloid (a mixture of very tiny particles that are dispersed in another substance but do not settle out of the substance) in which liquids that do not normally mix are spread throughout each other. By EMULSION!

Emulsifying is done by slowly adding one ingredient to another while simultaneously mixing. This disperses and suspends tiny droplets of one liquid through another. How Does Emulsion Work?

To prevent the mixture from separating, an ingredient, known as an emulsifier that is attracted to both oil and water is added, thus allowing the two to mix. Let’s look at how to make mayonnaise………….. How Does Emulsion Work? Continued.

Before attempting to make homemade mayonnaise, it is important to understand just how mayonnaise works. REMEMBER ……………..Mayonnaise is an emulsion of oil in lemon juice that has been stabilized by the molecule lecithin found in the egg yolks. Tips for Making Mayonnaise

Avoid having the components of the emulsion separate back into their individual components. This is called "turned" or "broken" mayonnaise. No matter how long you mix the oil and lemon juice together, it will always separate into a gooey mess UNLESS the egg yolk is added as a stabilizer. TIPS FOR MAKING MAYONNAISE

WHAT IS IN MAYONNAISE ?

The recipe for mayonnaise involves only a few ingredients BUT care is necessary when combining oil and the egg yolk. Liquids such as lemon juice, vinegar, or water may be added to adjust for taste and consistency. A FEW KEY INGREDIENTS

EGG YOLK ACID SEASONINGS OIL

Tips For Making Mayonnaise Room Temperature: Have all ingredients at room temperature. If they are not, warm the mixing bowl in hot water to take the chill off the egg yolks; heat the oil to tepid if it is cold. Egg Yolks: Always beat the yolks for a minute or two before adding anything to them. When they are thick and sticky, they are ready to absorb the oil. Adding The Oil: The oil must be added very slowly at first, in droplets, (unless using an immersion blender), until the emulsion process begins and the sauce thickens into a heavy cream. Then, the oil may be incorporated more rapidly. Proportions: The maximum amount of oil one large egg yolk can absorb is six ounces, or ¾ cup. When this maximum is exceeded, the binding properties of the egg yolks break down, and the sauce thins out or curdles. If you have never made mayonnaise before, it is safest not to exceed ½ cup of oil per egg yolk.

½ cup of light olive oil (less strongly flavored than standard olive oil) or other good quality oil 1 egg Juice of 1 lemon, or vinegar Pinch of salt (and pepper, if desired) Water (to thin the mayonnaise if needed) To make 1 cup of mayonnaise you will need:

Separate the eggs in your recipe. Reserve the whites for other recipes. STEP 1

Egg yolks contain a natural emulsifier, lecithin, which helps thicken sauces and bind ingredients.

Combine the egg and acid in the bowl, whisking to mix. You can make mayonnaise with an immersion blender, in a food processor, blender, or mixer, or by hand with a mixing bowl and whisk. For each cup of mayonnaise, add between 1 and 2 tablespoons of fresh lemon juice or vinegar, depending upon your tastes. STEP 2

Lemon juice or vinegar adds acidity to the mayonnaise. It also helps flavor the mayonnaise.

Continue to whisk constantly, adding the oil in a slow, steady stream. If the mayonnaise starts looking too thick, add enough water to thin it to the desired consistency. Add only about a teaspoon of water at a time. When the oil is all mixed in, the mayonnaise should be thick and fluffy, with your whisk forming ribbons through the mixture. STEP 3

Adjust the seasoning with the salt and pepper and more acid, if desired. White pepper is desirable in mayonnaise for it color.

If it never thickened and you are stirring a puddle, chances are you will need to start over.

There is concern about salmonella poisoning from raw eggs. However, egg substitute can be used to make homemade mayonnaise. Commercial mayonnaise is made with pasteurized eggs.

Use homemade mayonnaise on sandwiches, in dips, or in any recipes requiring mayonnaise. Dress it up with garlic for an aioli (all-i-oli), or herbs and olives for a remoulade sauce. Store fresh mayonnaise in the refrigerator and use within five days.

MAYONNAISE RECIPES Let’s take a look at some mayonnaise recipes before we make it in the lab.

IMMERSION BLENDER

An IMMERSION BLENDER -- some folks call it a "stick" blender -- mayonnaise takes about a minute and is foolproof. Make the mayonnaise in the beaker that comes with the immersion blender; it has 1 oz.-increment markings up the side, which makes measuring easier. Precise measurement of the oil is not crucial. However everything MUST be at room temperature, or the mayonnaise will not emulsify: 1/2 tsp salt 1 tsp dry mustard 1 tsp lemon juice or lime juice 1 tsp vinegar (plain white vinegar is fine, or rice, or apple cider) 1 egg Add enough extra virgin olive oil to bring the total amount to 4 oz., then enough canola (or other taste-free) oil to bring the total to 12 oz. Put the blender in so that it touches the bottom of the beaker. Turn it on, high speed, and hold it motionless for a count of 12 seconds. Then lift the blender up and push it down through the mixture as it emulsifies -- which will take maybe 15 or 20 seconds. That's it.

RESOURCES Introduction to Culinary Arts. Prentice Hall edition.