Raw Egg Mayonnaise (Homemade Food Safety Guide)

Homemade mayonnaise made with raw egg should use pasteurized eggs, clean equipment, and cold handling. Keep the finished sauce at or below 40°F (4°C), refrigerate it within two hours, or one hour above 90°F (32°C), and use it within three to four days. Lemon juice and vinegar add flavor, but do not make unpasteurized eggs reliably safe.

Homemade mayonnaise can let you choose the oil, seasoning, and amount of salt. But because it is not cooked, its safety depends on the egg and how you handle the sauce. Salmonella can be present in raw eggs, and fresh eggs or a thick, tangy emulsion are not proof that the bacteria are absent.

I use one simple rule when explaining this food: choose pasteurized eggs before you start, then keep the sauce cold. Pasteurization reduces the risk from harmful bacteria; it does not mean you can skip clean equipment or safe storage. The steps below cover preparation, serving, and what to do if the mayonnaise has been left out.

Choose eggs and equipment before you begin

The safest base for uncooked mayonnaise is a pasteurized shell egg or pasteurized liquid egg intended for use in recipes. Use clean equipment and a nonreactive bowl, such as stainless steel or glass. These choices reduce avoidable risk, though they cannot replace careful refrigeration and handling.

Which eggs are suitable?

Pasteurized eggs have been treated to reduce harmful bacteria while remaining usable in recipes that call for uncooked egg. Check the carton for the word “pasteurized.” If you use liquid egg, confirm that it is pasteurized and suitable for the recipe.

Ordinary raw shell eggs are not made reliably safe by adding lemon juice or vinegar. Nor does a clean-looking shell, a recent purchase date, or a fresh smell show that an egg is free of Salmonella. If you cannot confirm that the egg is pasteurized, choose a commercial mayonnaise or another recipe that cooks the egg.

Pick a suitable bowl and clean tools

Use a clean stainless-steel or glass bowl. Acidic ingredients such as lemon juice and vinegar can contact reactive metals, including aluminum or copper, so avoid those bowls for this preparation. A blender, immersion blender, or whisk can work if the recipe is designed for that method.

Before mixing, wash your hands with soap and water. Clean the bowl, blender parts, utensils, and work surface with hot, soapy water; rinse them, then sanitize food-contact items according to the sanitizer label. Start with cold, pasteurized eggs and keep other perishable ingredients cold.

Takeaway: Verify the egg is pasteurized and prepare a clean, nonreactive work area before opening it.

Make the emulsion without relaxing food-safety steps

An emulsion is a mixture in which tiny droplets of oil stay dispersed through a water-based ingredient, such as egg and lemon juice. To make mayonnaise, follow a reliable recipe and add the oil as directed. The technique builds texture, but it does not kill pathogens.

Step-by-step preparation

1. Wash your hands and set out clean, sanitized equipment. Keep the pasteurized egg and other perishable ingredients chilled until needed.
2. Measure the recipe’s lemon juice or vinegar, egg, and seasonings. Use the stated amounts; do not add less acid on the assumption that you can adjust it later for safety.
3. Combine the egg, measured acid, and seasonings as the recipe directs. Blend or whisk while adding the oil in a controlled stream, following the recipe until the mixture thickens.
4. Transfer the mayonnaise to a clean, covered container as soon as it is ready. Label it with the preparation date and refrigerate it promptly at 40°F (4°C) or colder.

Keep the mixing time focused. Do not leave the ingredients or finished sauce sitting at room temperature while you do other kitchen tasks. If the emulsion breaks or looks thin, that is a quality issue; it does not tell you whether the sauce is safe.

What acidity can and cannot do

Lemon juice and vinegar provide flavor and help balance the recipe. But a home cook cannot rely on their presence, taste, or amount to prove that an uncooked egg mixture is safe. Acidification is not a validated pathogen-kill step in an ordinary homemade mayonnaise recipe.

Takeaway: Follow the recipe for texture and flavor, but rely on pasteurized egg and cold handling for risk reduction.

Store, serve, and clean up safely

Cold holding means keeping food at a controlled refrigerator temperature. Store homemade mayonnaise, covered, at 40°F (4°C) or colder and use it within three to four days as a conservative household limit. Time out of refrigeration counts, including preparation and serving.

Temperature and time limits

Use a refrigerator thermometer if you are unsure whether the fridge is cold enough. Place the container in the refrigerator promptly, rather than leaving it on a counter to cool. During a meal, set out only the amount you expect to use and return the main container to the fridge.

Perishable food should generally be refrigerated within two hours at room temperature. If the room or outdoor temperature is above 90°F (32°C), the limit is one hour. These limits apply to the time the mayonnaise is out, not just to one uninterrupted stretch. When you do not know how long it sat out, discard it rather than trying to judge by smell or taste.

Serving and leftovers

Use a clean serving spoon each time. Do not return mayonnaise from a serving dish to the storage container, and do not dip utensils that have touched other foods into the main container. If guests will be eating over a long period, serve small portions and replenish them from the refrigerator.

Wash tools and food-contact surfaces with hot, soapy water after preparation. Rinse and sanitize them according to the product label. This helps prevent raw egg residue from spreading to ready-to-eat foods.

Takeaway: Keep the mayonnaise cold, track time out of the refrigerator, and discard it when the handling history is uncertain.

Consider who will eat it

People can have different levels of risk from foodborne illness. Pregnant people, young children, older adults, and people with weakened immune systems face a higher risk of serious illness from Salmonella. For them, choose mayonnaise made with pasteurized egg or a commercial product made with pasteurized ingredients.

Practical household scenarios

These examples show how the time and temperature rules work. They are common situations, not a reason to make exceptions to the limits.

• A family makes lunch: The cook uses a carton marked pasteurized, blends the mayonnaise, and refrigerates it right away. At lunch, they serve a small amount with a clean spoon. This follows the core steps.
• A picnic is delayed: A jar sits outside for more than two hours on a mild day. The safe choice is to discard it, even if it still looks and smells normal.
• A hot-day gathering: The room or outdoor temperature is above 90°F (32°C), and the mayonnaise has been out for over an hour. Discard it; the shorter time limit applies.
• A guest is pregnant: The host serves a commercial mayonnaise or homemade mayonnaise made with pasteurized egg. That avoids serving an uncooked mixture made with an unpasteurized egg to someone at higher risk.

Takeaway: When serving someone at higher risk, do not use unpasteurized raw eggs in uncooked mayonnaise.

Bottom line and quick answers

Homemade mayonnaise can be handled with a clear routine: use pasteurized egg, start with clean tools, keep the sauce at or below 40°F (4°C), and follow the time limits for serving. Do not treat acid, freshness, appearance, or taste as proof of safety.

Can I make mayonnaise with an ordinary raw egg?
It is not the safer choice. Use a pasteurized egg for uncooked mayonnaise, especially when serving people at higher risk.

Does lemon juice or vinegar kill Salmonella in homemade mayonnaise?
Do not rely on it to make unpasteurized raw egg safe. Use pasteurized egg and follow safe handling steps.

How cold should homemade mayonnaise be stored?
Keep it at 40°F (4°C) or colder in a covered container.

How long can homemade mayonnaise sit out?
Refrigerate it within two hours, or within one hour if the temperature is above 90°F (32°C).

How long does homemade mayonnaise keep in the refrigerator?
Use it within three to four days as a conservative household limit. Discard it sooner if it was not kept cold or its handling history is uncertain.

Can I tell whether mayonnaise is safe by smell or taste?
No. Harmful bacteria may not cause a noticeable change in smell, taste, or appearance. Do not taste it to test safety.

Can I use pasteurized liquid egg?
Yes, if the product is pasteurized and suitable for the recipe. Follow the recipe’s directions for the amount and method.

Is homemade mayonnaise safe for pregnant people or young children?
Choose mayonnaise made with pasteurized egg or a commercial pasteurized product. Avoid serving them mayonnaise made with unpasteurized raw egg.

Can I return leftovers from a serving bowl to the jar?
No. Keep serving leftovers separate from the stored mayonnaise and discard them if they exceed the time limit.

What should I do if I do not know how long the mayonnaise was unrefrigerated?
Discard it. When time or temperature control is uncertain, smell and taste are not reliable safety checks.

(This article was written by one of our staff writers, Richard K. Ellison. Visit our Meet the Team page.)