What causes mayonnaise to get runny?
Mayonnaise is an emulsion, which means it is a mixture of two liquids that normally don’t mix – oil and water. For mayonnaise to have the right texture, with a thick, creamy consistency, the emulsion needs to hold together properly. If the emulsion breaks down, the oil separates from the water, and you end up with a runny mess. There are a few main reasons why mayonnaise can become runny:
Using too much oil
Mayonnaise is made up of around 70-80% oil, which is carefully balanced with egg yolks and an acid like vinegar or lemon juice. If you add too much oil when making or remixing mayonnaise, it can throw off the emulsion and cause the mayo to break and become runny. Using an oil with a very light flavor, like canola or vegetable oil, can also make the emulsion more unstable. Stick with good quality extra virgin olive oil or avocado oil.
Adding ingredients that thin the mayo
Things like mustard, salsa, juice, etc. can introduce more moisture and acidity, which interferes with the emulsion. Whisking in a spoonful of water to thin out thick mayonnaise can also cause it to break down. If you want to add extra flavors to your mayo, do so in small amounts and whisk vigorously to maintain the emulsion.
Using underripe or overripe egg yolks
The egg yolks need to be at the right stage of ripeness to properly emulsify and thicken the mayonnaise. Underripe yolks don’t have enough emulsifying power, while overripe yolks are weakened and can cause the mayo to destabilize. Make sure you use eggs that have been refrigerated properly and aren’t past their prime.
Letting the mayonnaise sit too long
Even when you initially make a good emulsified mayo, the emulsion can start to break down over time as the ingredients slowly separate. This is especially true if the mayo has been sitting out unrefrigerated. The mayo can look perfectly fine at first, then later turn runny after an hour or more passes. Refrigerating helps slow this process, but homemade mayo is best used within 3-4 days.
Using unstable oils
Oils like grapeseed, sesame, or extra virgin olive oil can sometimes contribute to a broken emulsion because they are more prone to separating. Stick with neutral-flavored oils like canola, vegetable or light olive oil. You can incorporate smaller amounts of more unstable oils once the emulsion is formed.
Failing to properly emulsify the ingredients
Mayonnaise relies on strong, steady emulsification to disperse the oil droplets and create a stable mixture. If the oil is added too quickly, or isn’t whisked vigorously enough into the egg yolks, the emulsion will quickly break and produce runny mayo. Make sure to add the oil very slowly at first, literally drop-by-drop, while constantly whisking.
How to fix runny mayonnaise
If your mayonnaise does turn runny, don’t toss it out right away! There are a few tricks you can try to resuscitate it and bind it back into a nice thick emulsion.
Whisk in a replacement egg yolk
Since egg yolks are so vital for creating the emulsion, you can sometimes fix a broken mayo by whisking in a fresh egg yolk. Make sure the replacement yolk is at room temperature. Whisk vigorously as you drizzle the runny mayo into the yolk to give it another chance at emulsifying.
Whisk in a teaspoon of mustard
Mustard contains emulsifiers that can help reincorporate the separated ingredients. Whisk in mustard a teaspoon at a time until the mayonnaise begins to thicken. Dijon and whole grain mustards work best to revive a runny emulsion.
Try a few drops of lemon juice
The acidity helps balance and tighten the emulsion, while the emulsifiers in the egg yolk cling to the oil droplets. Whisk in fresh lemon juice starting with just a few drops at a time until it reaches the right consistency.
Blend in 1-2 teaspoons of cold water
This helps re-disperse the moisture within the emulsion. Slowly whisk in the cold water and let it redistribute. Don’t add too much or it can make the mayo too thin.
Whisk while slowly streaming in more oil
Sometimes you can salvage a runny mayo by continuing to emulsify it properly. Whisk vigorously while very slowly drizzling in more oil until it thickens and comes back together. Use just a few drops at first to see if the emulsion stabilizes before adding more.
Transfer to a food processor or blender
If whisking by hand isn’t cutting it, transfer the mayo to a food processor or stand blender. Let it run for 1-2 minutes to fully reincorporate the ingredients. Slowly drizzle in more oil if needed to restore the right texture.
Chill in the refrigerator for 1 hour
Letting the mayo rest in the fridge gives the ingredients time to re-emulsify on their own. The cold temperature helps firm and set the emulsion. After chilling, give it a quick whisk to check the consistency.
Stir in an egg white
For a really broken mayo, adding an egg white can provide extra emulsifying power. Make sure the egg white is chilled. Gently fold it into the runny mayo until combined.
Add a spoonful of flour or cornstarch
These powdery starches can instantly bind up excess moisture and help thicken the mayonnaise. Whisk in no more than 1-2 teaspoons and let sit briefly before checking the texture.
Tips for preventing runny mayonnaise
Once you’ve fixed your runny mayo, keep these tips in mind next time you make it to help prevent the emulsion from breaking in the first place:
Use the freshest egg yolks possible
Old yolks don’t have the strength to hold the emulsion together properly. Separate eggs when refrigerated and use the yolks immediately for optimal freshness.
Make sure all ingredients are at room temperature
Cold ingredients make it harder to form a stable emulsion. Let eggs, oil, vinegar, and lemon juice come fully to room temp before starting.
Add the oil excruciatingly slowly at first
The most important step is forming the initial emulsion, so take it drop by drop until the mayo begins to thicken before pouring in a steady stream.
Whisk vigorously the entire time you add oil
Continuous tight whisking creates smaller oil droplets for a more stable emulsion. Don’t take a break halfway through or let your arm rest.
Use a neutral-flavored oil like canola or vegetable
The lighter oil integrates more smoothly than heavy olive oil. You can mix in some olive oil once the emulsion takes shape.
Stop whisking as soon as it thickens
Overbeating can cause the emulsion to break down. Whisk just until it forms stiff peaks, then immediately transfer to a jar.
Consider adding mustard for extra emulsifiers
Prepared mustard contains vinegar as well as emulsifying agents that boost the mayo’s stability. Add 1 teaspoon per egg yolk.
Don’t add more than 1-2 tbsp of lemon juice per yolk
Too much acidity causes the proteins to lose their emulsifying power. Start with just a squeeze and incorporate more to taste.
Add salt and pepper for flavor after emulsifying
Salt can interfere with emulsion formation so season at the end once the mayo has fully thickened.
Refrigerate immediately after making
Cold temperatures help lock in the emulsion. Letting homemade mayo sit out invites the ingredients to slowly separate.
Storing mayonnaise properly
Proper storage is also key to prevent a perfect homemade mayonnaise from breaking down later:
Transfer to an airtight container
A tight seal minimizes air exposure to help maintain freshness and prevent liquid from evaporating out.
Make sure your jar is completely clean
Any remnants of old mayo or oils left in the jar can destabilize your fresh new batch. Wash carefully with hot soapy water.
Press plastic wrap directly on the surface
This prevents a skin from forming and locks in moisture. Refrigerate sealed under the plastic wrap.
Never store mayo at room temperature
The emulsion will slowly deteriorate. Refrigeration is critical for longevity.
Use within 3-4 days for best quality
The emulsifiers can only preserve it for so long before the mayo starts to break down in the fridge.
Freeze extra mayonnaise in ice cube trays
For longer storage, freeze cubed portions of leftover mayo to maintain the freshness. Defrost in the refrigerator before using.
Keep mayo made with olive oil to 2-3 day maximum
The polyunsaturated fats in olive oil are more prone to spoiling. Stick with more shelf-stable oils for longer-lasting mayo.
Store opened mayonnaise upside down in the fridge
This creates a tighter seal preventing air from contacting the surface and drying it out.
Tips for making stable flavored mayonnaise
Adding extra flavors and ingredients to homemade mayonnaise increases the risk of breaking the emulsion. Here are some ways to keep flavored mayo stable:
Whisk in dry seasonings after emulsifying
Ingredients like garlic powder, onion powder, dried herbs, and spices won’t compromise the emulsion. Avoid salt until the mayo has set.
Fold in chopped fresh herbs and vegetables
Gently stir in diced onions, herbs, roasted garlic, etc. once the mayonnaise has fully emulsified to prevent them from releasing moisture.
Use an extra yolk when adding wet ingredients
Ingredients like mustard, salsa, or chipotle peppers in adobo introduce more moisture. Fortify the emulsion with an extra yolk per 1/4 cup of wet add-ins.
Limit acidic ingredients to 1 tablespoon per yolk
Ingredients like vinegar, citrus, tomatoes, and wine add acidity that can destabilize the emulsion. Add small amounts gradually.
Blend in creamy ingredients like avocado or yogurt
The fat and emulsifiers in these help create a smooth, stable emulsion. Fold them in gently just until incorporated.
Temper additions with a bit of the finished mayo
Before folding wet ingredients into a finished mayo, mix them first with a spoonful or two of the mayo to temper them.
Reinforce the emulsion by blending in an ice cube
The chilled water helps tighten the emulsion just enough to prevent additions from breaking it down too much. Discard ice chunk before using mayo.
If it breaks, re-emulsify in a blender or food processor
The high-speed blending fully reincorporates separated flavored mayo. Stream in more oil if needed to stabilize.
Conclusion
A runny, broken mayonnaise can be fixed! With some rapid whisking, strategic ingredient additions, chill time, and/or mechanical re-emulsifying, you can often resuscitate a runny mayo and restore it to a luscious creamy texture. Be sure to store it properly and take precautions when flavoring it to give your homemade mayo the longest shelf life possible. With practice, patience, and these handy tips, you’ll be churning out perfect mayo every time.