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Does Molasses Ever Go Bad? [Shelf Life & Spoilage]

In a Nutshell:

  • Molasses shelf life: lasts for a few years beyond the expiration date and retains best quality for about a year after opening
  • Spoilage signs: sour smell and mold
  • Storage methods: airtight container, cool and dark place. No need to refrigerate molasses even after opening the bottle.

We all know that molasses is a thick syrup derived from sugar production, and it’s often the unsung hero in many recipes, adding a touch of sweetness and depth to your culinary creations. But what about its shelf life?

Does molasses go bad, and how do you know when it’s time to toss that bottle? And how do you store it to make it last as long as possible?

In this article, we’ll answer all those questions. Stick around to learn all the tips and tricks to ensure your molasses stays fresh and flavorful for as long as possible!

While there are a few types of molasses available, including light molasses, dark molasses, and blackstrap molasses, they are pretty similar in terms of storage practices and shelf life. What’s different is how the molasses tastes and in which recipes you use it.

Sugar beet molasses on a spoon
Sugar beet molasses on a spoon

How Long Does Molasses Last?

Unopened store-bought molasses easily lasts for 1+ years beyond the printed date. After you open the bottle, the sweetener will taste best for up to a year but will stay safe to eat for much longer.

As you can tell, it’s a pretty hardy condiment, much like other liquid sweeteners such as maple syrup or honey.

Now, let’s get into the details.


Molasses typically has a shelf life of a few years. And unopened bottles of molasses last well beyond their “expiration” date. So as long as the bottle is intact, the sweetener derived from sugar beets or sugarcane should be safe to use, too.

(How long does molasses last beyond the best-by date? We’ll discuss that shortly.)

Just remember to keep it in a cool, dark place, like a pantry or a cupboard, and it’ll be fine for a long time.

After Opening

Once you’ve opened your molasses, it’ll taste best for six months to a year but will stay safe to use for months, if not years, longer. And you can use the sweetener as long as it doesn’t show any signs of spoilage and the quality is good enough for you.

Of course, the molasses will gradually degrade in quality, but its decline in flavor is much slower than in many other long-lasting condiments, such as ranch or Italian dressing. It’s more similar to that of soy sauce.

Next, let’s talk about what to do about molasses that’s past the printed date.

Black Cane Sugar Molasses in a Bowl
Black Cane Sugar Molasses in a Bowl

Expired Molasses

If you find an ancient bottle of molasses hiding in the back of your pantry, you might wonder if it’s still good.

As you already know, the shelf life of molasses is quite long. And fortunately for you, the sweetener stays safe to use well beyond the date printed on the label.

Expired molasses might not be as flavorful as it once was, but it’s not necessarily harmful to consume. As long as there are no spoilage signs present, the liquid should be okay to use.

Of course, if you get to a point that your molasses is 5 years expired and you’re not comfortable using it, tossing it is your best course of action.

So, now that you know how long molasses lasts, let’s move on to the signs that indicate it’s time to say goodbye to that bottle.

How to Tell if Molasses is Bad?

You can usually tell if molasses has gone bad by checking for a sour smell, mold, or degraded flavor. These signs indicate that your molasses has spoiled and you should open a new bottle.

Let’s go through those changes one by one.

Sour Smell

A sour smell is the first and most obvious sign that your molasses has gone bad.

Fresh molasses typically has a sweet and slightly earthy aroma. But if you open the bottle and catch a whiff of something sour or off, it’s time to say goodbye to your molasses.

This is similar to most other condiments like fish sauce or tartar sauce, which also develop an off smell when spoiled.


Another sign of spoiled molasses is the presence of mold. This is a clear indicator of bacterial growth, and you should discard the molasses if you spot any fuzzy or discolored patches on the surface or neck of the bottle.

Some sources say you can remove mold spots on the surface and use the rest, but I suggest throwing the product out just to be safe. No need to risk food poisoning.

Pouring molasses from a bottle
Image used under Creative Commons from Marshall

Flavor Change

If your molasses’ flavor has changed and it now tastes pretty bad, it’s time for it to go. I’m sure you already do the same with all other food products.

Now, if you’re not a frequent molasses user, that might be easier said than done, so here’s a quick breakdown of what to expect from the most popular types:

  • light molasses is the sweetest, and its flavor is pretty light
  • dark molasses is less sweet, but the flavor is stronger
  • blackstrap molasses is the least sweet and has some bitterness to it; it’s also the densest

Armed with that knowledge, you should be able to tell if your molasses is spoiled.

Now that we’ve covered the signs of spoilage, let’s briefly talk about how temperature affects the thick sweetener.

Black Molasses in a Bowl and a Spoon
Black Molasses in a Bowl and a Spoon

Cold Molasses is Thick Molasses

If you refrigerate molasses or place it somewhere really cool, it’ll thicken even further. That’s the nature of the beast, and super thick molasses isn’t spoiled molasses.

(Ever heard the phrase “slow as molasses in January”?)

Because of that, you should probably think twice before placing your molasses bottle in the fridge.

If you need it less viscous, place the bottle in a pot of warm water for an hour or two. That will loosen it up and get it back to its normal state.

Now that you know how to spot actual signs of spoilage and that thick molasses is okay to use, it’s time to talk about refrigerating molasses.

Does Molasses Need to Be Refrigerated?

The short answer is no, molasses doesn’t need to be refrigerated, whether it’s unopened or opened. As long as it’s stored properly in a cool, dark place like a pantry or a cupboard, your molasses will stay fresh and flavorful.

That’s the gist of it. Now, let’s talk about why.

Molasses in a dish
Molasses in a dish

Why Refrigeration Isn’t Necessary

Molasses has a high sugar content, which acts as a natural preservative. This means that it’s less prone to spoilage than other condiments like mayonnaise or salad dressing, which require refrigeration after opening.

The super thick consistency of molasses also helps with preventing bacteria growth.

This is why most bottles of molasses (except for maybe the odd flavored molasses) can be safely stored at room temperature without any issues.

With this in mind, let’s move on to some storage tips that will help you keep your molasses in prime condition.

How to Store Molasses

Storing molasses properly is crucial for maintaining its quality, flavor, and shelf life. Here are some storage tips to help you get the most out of your molasses:

Choose the Right Container

Always store your molasses in an airtight container. Most store-bought molasses comes in airtight bottles, so you can simply use the original packaging.

If you’re transferring molasses to a different container, make sure it has a tight-fitting lid to prevent any exposure to air or contaminants.

This is similar to storing other condiments like mustard or oyster sauce.

Keep It Cool and Dark

You should store molasses in a cool, dark, and dry place. That’s because heat and light exposure can degrade the quality and flavor of the sweetener made from sugarcane or sugar beets.

A pantry or cupboard away from direct sunlight and heat sources, like your stove or oven, is ideal.

This is a common storage practice for pretty much all condiments, such as barbecue sauce, sriracha, or hoisin sauce.

Keep It Clean

Lastly, make sure to keep the bottle clean. Wipe off any spills or drips on the bottle after using your molasses.

Or at least after every couple of uses.

(I’m trying to keep it real here.)

This will help prevent cross-contamination from other food items or anything else that might’ve found its way into your kitchen or pantry cabinet.

By following these storage tips, you can ensure your molasses stays fresh and ready to enhance your favorite recipes!