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How long can you keep walnut oil?
You can keep walnut oil for about 6 to 12 months when it’s unopened and stored properly, and around 3 to 6 months once you’ve opened the bottle.
That said, how long you can keep walnut oil depends on a few key factors like storage conditions, the type of oil, and whether it’s refined or unrefined.
If you’ve ever wondered how long you can keep walnut oil before it goes bad, you’re in the right place.
In this post, we’ll explore how long you can keep walnut oil, the signs it has gone rancid, and the best ways to store it so it lasts as long as possible.
Let’s get into it.
How Long Can You Keep Walnut Oil?
How long you can keep walnut oil mostly comes down to whether it’s opened or unopened, and how it’s stored.
Here’s a quick breakdown of the shelf life you can expect.
1. Unopened Walnut Oil Lasts 6 to 12 Months
An unopened bottle of walnut oil can last anywhere from 6 to 12 months from the date of purchase.
Some high-quality brands even print a best-by date that stretches to 18 months if the oil is stored in ideal conditions.
The key here is that an unopened bottle is protected from oxygen and light, which are the two biggest enemies of walnut oil.
So as long as you keep it sealed and cool, you can keep walnut oil for a good while before ever breaking the seal.
2. Opened Walnut Oil Lasts 3 to 6 Months
Once you open that bottle, the clock starts ticking faster.
How long you can keep walnut oil after opening depends on how often you use it and how you store it.
Most opened bottles stay fresh for about 3 to 6 months when kept in the fridge.
If you leave it in a warm pantry, that window shrinks to as little as 1 to 2 months.
So if you want to keep walnut oil fresh longer, refrigeration is your best friend.
3. Refined vs. Unrefined Walnut Oil
The type of walnut oil you buy also affects how long you can keep it.
Refined walnut oil has been processed to remove impurities, which gives it a longer shelf life.
Unrefined or cold-pressed walnut oil, on the other hand, retains more natural compounds but spoils faster.
So if you’re buying cold-pressed walnut oil for its rich flavor, plan to use it sooner rather than later.
Signs Your Walnut Oil Has Gone Bad
Even if you follow all the storage rules, walnut oil can still turn on you.
Here’s how to tell when it’s time to toss it.
1. A Sharp or Bitter Smell
Fresh walnut oil smells nutty and pleasant.
If yours smells sharp, bitter, or vaguely like old paint, that’s a clear sign it has gone rancid.
Rancid oil won’t always make you sick right away, but it tastes awful and loses all its nutritional value.
So when in doubt, give it a sniff before you drizzle it on anything.
2. A Change in Color or Texture
Fresh walnut oil is usually a light golden or amber color.
If it starts looking darker, cloudy, or thicker than usual, that’s another red flag.
Texture changes often mean oxidation has set in, which means you can no longer keep walnut oil in usable condition.
3. An Off or Bitter Taste
If the smell doesn’t give it away, a tiny taste will.
Fresh walnut oil tastes mild and nutty.
Rancid oil tastes bitter, sour, or just plain wrong.
If you get that bitter hit on your tongue, spit it out and dump the bottle.
How to Store Walnut Oil So It Lasts Longer
Want to keep walnut oil fresh for as long as possible?
Here’s how to do it right.
1. Keep It in a Cool, Dark Place
Light and heat are the fastest ways to ruin walnut oil.
Store your bottle in a cool, dark cabinet away from the stove, or better yet, in the fridge.
This single habit can dramatically extend how long you can keep walnut oil.
2. Seal the Bottle Tightly
Oxygen speeds up oxidation, which is what makes oil go rancid.
Always screw the cap on tightly after each use.
If you use walnut oil often, consider transferring it to a smaller bottle as the level drops, so less air sits inside.
3. Skip the Fridge Door
The fridge door might seem like a handy spot, but it’s actually the warmest part of the fridge.
Every time you open and close the door, the temperature fluctuates.
Instead, tuck your walnut oil toward the back of the fridge where it stays consistently cold.
4. Buy Small Bottles
Since walnut oil has a shorter shelf life than many other oils, buying smaller bottles is smart.
You’ll use it up before it has a chance to go bad.
Plus, fresh walnut oil tastes way better than oil that’s been sitting around for months.
So, How Long Can You Keep Walnut Oil?
You can keep walnut oil for about 6 to 12 months unopened and 3 to 6 months once opened, as long as you store it properly.
Refined walnut oil lasts longer than cold-pressed, unrefined versions.
And once it smells sharp, tastes bitter, or looks cloudy, it’s time to let it go.
Hope this post has helped you understand how long you can keep walnut oil and how to store it so it stays fresh for as long as possible.