Making a batch of homemade mayonnaise allows you to enjoy this great-tasting condiment without the preservative and additives found in store-bought mayo. Unfortunately, the preservatives used in store-bought mayo are also responsible for increasing its shelf life.
Without preservatives, your homemade mayonnaise may only last three to four days. However, the freshness of your mayo depends on a variety of factors, including the size of the batch, the temperature of your fridge, and the type of container.
You can make homemade mayo last longer by fermenting it or attempting to freeze it.
How to Ferment Homemade Mayo to Make it Last Longer
You can ferment homemade mayonnaise to extend its life. Add whey to the ingredients when preparing your homemade mayo.
Whey is often used as a starter culture for the fermentation process, as it reduces the time needed to produce lactic acid. Lactic acid is considered nature’s preservative, as it helps regulate pH levels and limit the growth of microorganisms.
You can purchase whey or obtain it from fermented or cultured dairy products. To obtain whey, strain yogurt, cultured buttermilk, or kefir.
The liquid that you extract can be added to any homemade mayonnaise recipe to increase its longevity. Instead of lasting just a few days, your mayo may stay fresh for up to 30 days.
Include about one tablespoon of whey per half-cup batch of homemade mayo. After mixing the ingredients, allow the mayo to sit at room temperature for five to eight hours.
Allowing the mayo to sit at room temperature helps activate the bacteria in the whey, which starts the fermentation process. After waiting up to eight hours, place the mayo in an airtight container and set it in the fridge.
How to Freeze Homemade Mayonnaise
Mayonnaise does not typically freeze well. After the mixture thaws, the solid and liquid ingredients tend to separate.
The mayo may appear curdled with a layer of liquid on top. However, you can minimize the separation of ingredients when freezing and thawing mayo.
You will need freezer-safe glass jars with air-tight seals. Place the jars in boiling water for five minutes to sterilize them.
Fill the jars with your homemade mayo. You may need to occasionally press the mayo down with a spoon to eliminate air bubbles.
Air bubbles increase the risk of freezer burn. The small pockets of air allow surrounding moisture to transform into gas.
Freezer burn does not make food unsafe. However, it reduces its moisture and flavor.
You also want to avoid filling the jars to the very top. You want to leave a small space, as pressure from the ingredients expanding may cause the jar to break.
Close the lid and ensure that the jar is completely sealed before placing it in the freezer. It is also a good idea to add a label with the date that you froze the mayo.
You can keep the mayo in the freezer for up to five months. However, after allowing the mayo to thaw, you should not refreeze it.
Place the mayo in the fridge and use it within three to four days.
How to Thaw Frozen Homemade Mayonnaise
To thaw frozen mayo, place it in the fridge. It may take about 24 hours for it to thaw.
As mentioned, the ingredients will start to separate as the mayo thaws. Drain the excess liquid from the top.
Scoop the contents of the jar into a bowl. Whip the ingredients with a wooden spoon or an electric mixer.
Whipping the ingredients helps restore the consistency of the mayo. You may also need to add a few drops of water to help the ingredients blend.
How Long Does Homemade Mayo Last at Room Temperature?
According to the USDA, you should never leave mayo out for more than eight hours. Mayo needs to stay at temperatures of 50 degrees Fahrenheit or lower.
After eight hours at room temperature, bacteria and mold start to form. Leaving mayo out also increases the risk of salmonella poisoning.
Homemade mayo contains raw eggs, which are safe to eat in moderation when stored in the right conditions. While the USDA recommends discarding mayo after eight hours, you may want to avoid leaving it out of the fridge for more than two hours.
After two hours, the ingredients start to separate. Mayo that is left out longer may still be safe to eat but is likely to lose some of its flavors.
How Do You Know If Homemade Mayo Has Gone Bad?
Without whey, homemade mayonnaise may only last a few days. As mayo goes bad quickly, you may struggle to tell whether it is still safe to eat.
Here are some of the most common signs that you need to throw out your mayo:
- Yellow or brown appearance
- A layer of liquid on top
- Sour taste or smell
- Visible mold growth
Homemade mayo should have a creamy, off-white color. The egg yolk and mustard are yellow, but the remaining ingredients are white.
If the mayo starts to turn yellow or brown, it is likely starting to go bad. The discoloration is typically due to a loss of moisture.
If the container is not properly sealed, the ingredients may start to harden, resulting in a darker color.
The ingredients also gradually separate as bacteria starts to grow. A layer of liquid may appear on top of the mayo, which is a sign that you need to throw it out.
Keep in mind that ingredients also separate after thawing frozen mayo. The separation of ingredients during thawing is due to the temperature changes and not the presence of bacteria.
Mayo is typically made with white vinegar, which has a slightly acidic odor and flavor. However, the odor and flavor should not be strong.
If the sour taste or smell is noticeable, the eggs have likely gone bad. Toss the mayo instead of eating it.
Visible mold growth is an obvious sign that the mayo has gone bad. You may notice fuzzy white, blue, or green growth on the surface of the mayo, which indicates the presence of mold.
What Happens If You Eat Spoiled Homemade Mayo?
Gastrointestinal distress is the most common issue that occurs after eating spoiled mayo. You may experience stomach aches, diarrhea, and nausea.
Yet, eating spoiled mayo also increases the risk of a salmonellosis infection. Salmonella is a bacterial disease that affects the intestinal tract.
While most people recover from salmonella infections within a few days without treatment, some individuals may experience more severe symptoms.
Severe symptoms of salmonella include diarrhea, fever, and abdominal cramps. However, diarrhea can lead to dehydration and other life-threatening complications for those with pre-existing medical conditions.
Homemade mayo may only stay fresh for up to four days when stored in a fridge. You can also freeze it for up to five months but thawing it involves extra steps.
After thawing the mayo, the ingredients may separate. You can pour out the excess liquid and mix the remaining ingredients to reuse the thawed mayo.
The easiest way to make homemade mayo last longer is to add whey and allow the mixture to ferment. After allowing the mixture to ferment for up to eight hours, place it in a fridge and use it within 30 days.
I have a bachelor’s degree in Film/Video/Media Studies, as well as an associates degree in Communications. I began producing videos and musical recordings nearly 15 years ago. I am a guitarist and bassist in Southwest MI and have been in a few different bands since 2009, and in 2012 I began building custom guitars and basses in my home workshop as well. When I’m home, I love spending time with my three pets (a dog, cat, and snake) and gardening in my backyard.