How Long Does Kewpie Mayo Really Last? (Opened & Unopened)

Kewpie mayonnaise is a popular Japanese brand of mayonnaise. The name of the company that manufactures this product is also Kewpie.

This mayonnaise is now a household staple in Japan and is also popular in many other countries.

It is sometimes called “Japanese mayonnaise” due to its country of origin.

Kewpie mayo has a creamier texture and umami-like flavor thanks to its simple but flavorful ingredients. It’s both sweet and tangy.

While kewpie mayo can now be found in many grocery stores like Target or Walmart as well as online, you may be questioning how long it’s good for once you actually find it.

Can you let it sit out, or does it need to be refrigerated? Does it go bad, and if so, how quickly?  What’s the best way to store kewpie mayo?

Kewpie mayo lasts 10-12 months unopened when it’s stored properly in a pantry or dimly lit, room temperature area. When opened, kewpie mayo is good for one month if refrigerated immediately. It can be left out unrefrigerated for up to 8 hours.

Delicious homemade cod roe fish meatballs. Fish cutlets decorated with salmon.

Do You Keep Kewpie Mayo in the Fridge?

Opened kewpie mayonnaise should be kept in the fridge, as 37 – 40°F is the safest temperature for kewpie mayo. Unopened kewpie mayo doesn’t need to be stored in the fridge.

How Long Does Kewpie Mayo Last Unopened?

An unopened jar or squeeze bottle of kewpie mayonnaise can last for 10-12 months.

Unopened, the mayo should be stored in a cool place out of direct sunlight so that it stays at its highest quality. The ideal location is a pantry or cabinet at room temperature.

How Long Does Kewpie Mayo Last After Opening Unrefrigerated?

If you accidentally leave kewpie mayo out at room temperature, it can last up to 8 hours.

After 8 hours you should toss out the product as it is no longer safe and may contain harmful bacteria.

How Long Does Kewpie Mayo Last After Opening in Fridge?

An open bottle of kewpie mayo can last one month in the fridge.

According to the Kewpie company, it will decline in quality quickly after one month and should be tossed out.

Does Kewpie Mayo Need to Be Refrigerated After Opening?

Yes, kewpie mayonnaise needs to be refrigerated immediately after opening for safe consumption.

For best results, store the bottle in the refrigerator door shelf as being in temperatures too cool, like the interior of the fridge, will actually make the quality go down faster.

Kewpie mayo should be kept in the temperature zone of 37 – 40°F, considered the safe zone.

Food like mayonnaise that is left out for longer periods of time in higher temperatures may go bad and cause illness.

How Long Does Kewpie Mayo Last In the Fridge?

Once you store your kewpie mayonnaise in the fridge, it is good for one month. For the best quality and taste, try to use the product up as quickly as you can.

Luckily kewpie mayo works in a surprising array of recipes to add flavor and creaminess to a dish.

Unopened, unrefrigerated10-12 months
Unopened, refrigerated10-12 months
Opened, unrefrigerated8 hours
Opened, refrigerated1 month
Left out accidentally at room temperature8 hours
Past expiration date, unopened2-3 months
Past expiration date, opened1 month

How To Store Kewpie Mayo After Opening

The best way to store kewpie mayo once opened is in the bottle or jar it came in. Kewpie designs their packaging to keep the mayonnaise at its highest and best quality when stored.

As soon as you open the bottle of mayonnaise and are no longer using it, place it in the refrigerator door.

The refrigerator door is the best place for kewpie mayo as it stays out of direct, cold temperatures, which can be damaging to the quality, while still staying cool.

If for some reason the original bottle becomes damaged, kewpie mayonnaise can also be stored in an air-tight, food-safe container.

Home-baked mayonnaise

How Long Does Kewpie Mayo Last Past Expiration Date Unopened?

The expiration date on kewpie mayo is the last date that the product will be at its highest quality.

An unopened bottle of kewpie mayo will last 2-3 months past the expiration date.

How Long Does Kewpie Mayo Last Past Expiration Date Opened?

Once kewpie mayo is opened, it is good for one month regardless of the expiration date.

How Long Is Kewpie Mayo Good For?

Unopened kewpie mayonnaise can be kept in a pantry or refrigerator for 10-12 months.

Opened kewpie mayo should only be kept for one month and preferably used up in a shorter time frame.

Does Kewpie Mayo Go Off?

Yes, like other mayonnaises, kewpie mayo can go off or go bad/spoiled. There are several ways this can happen.

Storing your kewpie mayo incorrectly, keeping opened bottles out of refrigeration for long periods of time and keeping the open and refrigerated bottle out past one month.

How Do You Know If Kewpie Mayo Is Bad?

There are quite a few ways to tell if kewpie mayo is bad. It’s as simple as using your senses:

  1. Change of texture – the mayonnaise will no longer have a smooth and creamy texture, but may instead look chunky or curdled.
  2. Smell – it will have a sour smell. Even a slightly sour smell should be taken seriously.
  3. Taste – it will also taste more sour than usual.
  4. Mold or discoloration – visual changes are common when kewpie mayo goes bad. Mold may be visible on the mayonnaise itself or inside the bottle. The mayonnaise might also be discolored (a darker color than it normally is).

If you are unsure if your kewpie mayo is bad, check first by looking at the surface and texture, and then try smelling it for hits of spoilage.

If you still aren’t sure, taste a small bit of mayo to see if it has a sour flavor. If not, it is safe to continue using.

Can You Get Sick from Bad Kewpie Mayo?

Yes, like all foods that require refrigeration and go bad, you can get sick from kewpie mayonnaise.

It may be as simple as feeling a little nauseous or as serious as getting food poisoning.

A few signs of food poisoning, according to the FDA, are:

  • stomach cramps
  • diarrhea
  • nauseas
  • fever
  • vomiting
  • headaches
  • muscle weakness

If symptoms worsen, contact a doctor for recommendations.

Can You Freeze Kewpie Mayo?

Yes, you can freeze kewpie mayo if necessary, but the quality will not be as good once defrosted.

Kewpie mayo separates when it reaches a temperature below 32°F and may not have as flavorful a taste.

How to Defrost Kewpie Mayo

If you have decided to freeze your kewpie mayo, place it in the refrigerator to defrost slowly 24 hours prior to when you will need to use it.

Once defrosted, stir the mayo as it will have separated when frozen.

To give defrosted kewpie mayo a boost of flavor and texture, follow these steps:

  1. Let the mayonnaise warm up to around 37 – 40°F
  2. Add a few drops of rice or apple cider vinegar
  3. Stir until the consistency is creamier and looks unbroken

Does Kewpie Mayo Separate?

Yes, like many foods, kewpie mayo may separate. This only happens if the mayo is stored at a temperature below 32°F.

When kewpie mayo is made, the ingredients are emulsified.

Emulsification forces the liquids in the ingredients to become suspended in one another as they can’t actually mix. Freezing kewpie mayo will naturally separate this emulsification once more.

Can You Eat Kewpie Mayo If It Separates?

Yes, you can still eat kewpie mayo if it has separated and has been stored correctly otherwise.

The texture will not be as creamy or consistent as the original kewpie mayo, but it is still edible.

If you try to mix separated mayo and it doesn’t come together again, it’s safer to toss this mayonnaise out as it may no longer be good and definitely will not taste great anymore.

Kewpie Mayo vs. Regular Mayo

Kewpie mayonnaise and regular mayonnaise differ slightly in ingredients. Regular mayonnaise is made of whole eggs, oil and white vinegar.

Kewpie mayonnaise is made of egg yolks only and rice or apple cider vinegar in a base of neutral oil (like canola or grapeseed oil).

Because of the different ingredients, kewpie mayo has a creamier texture and a much richer flavor. It also doesn’t last as long as regular mayonnaise.

Many people who don’t like regular mayonnaise enjoy kewpie mayo.

The color of kewpie mayo is also noticeably different as the egg yolks give it a more yellow or golden look. There are about 4 egg yolks in every 500 gram bottle of kewpie mayo.

How Long Does Mayo Last After Opening?

Normal mayonnaise that is refrigerated after opening will last up to two months.

Some normal, store-bought mayonnaises may contain preservatives to make it last longer.

What Does Kewpie Mayo Taste Like?

With the use of rice or apple cider vinegar, kewpie mayo has a tangy/sour taste to it as well as a bit of sweetness. It is much more flavorful than regular mayonnaise.

Umami, a savory flavor considered the fifth flavor profile, also plays a strong part in kewpie mayo’s taste. Kewpie mayo gets the umami flavor from MSG (or monosodium glutamate 621).

Does Kewpie Mayo Have Dairy?

Kewpie mayo does not contain dairy and is considered dairy-free. However, kewpie mayo is not vegan due to the use of eggs. People who have egg allergies should not consume kewpie mayo.

How to Make Kewpie Mayo

It’s possible to make kewpie mayo at home if you are unable to find it in the store or want to try it before purchasing.

To make kewpie mayo, gather the following ingredients:

  • 2 egg yolks at room temperature
  • 1 ½ cups neutral oil (canola, grapeseed, etc.)
  • 2 tbs. rice or apple cider vinegar
  • 1 tsp salt
  • 2 tsp sugar
  • 4 tsp lemon juice
  • ½ tsp Dijon mustard
  • ¼ tsp dashi powder (adds the umami taste, but not necessary)

Mix all of the ingredients in a small bowl until the sugar, salt and dashi have dissolved.

The mayonnaise may need to be mixed longer to achieve a thick texture. Store homemade kewpie mayo in a glass jar or air-tight container in the refrigerator for 1 month.

Kewpie Mayo Storage Chart

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