How To Tell If Coffee Is Rancid? – A Definitive Guide

“How to tell if coffee is rancid?” is the first question that pops into our mind when we suddenly remember that pack of coffee beans that has been sitting on the shelf for months. 

Well, coffee beans are organic products and will definitely degrade over time. As I always say, the best time to brew that coffee is yesterday! But we are all human and we do get absent-minded at times. 

Unfortunately, you definitely cannot tell if your coffee has gone rancid with just visual judgment. So in this blog post, I will share some insights on how to tell if your coffee has gone rancid and of course some of the best practices to prevent it. 

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At a glance: How To Tell If Coffee Is Rancid And Steps To Prevent It

Four Signs Of Rancid Coffee

First, before we determine if your coffee has gone rancid, to cover some coffee basics we first have to understand what is rancid. 

By definition, rancid is an unpleasant smell or taste that is evident when it comes to fats and oils. The keywords here are “smell”, “taste”, and “oils” because these are the main factors that determine if your coffee has gone rancid. 

So visually, fresh coffee beans and rancid coffee beans will almost look identical. Perhaps rancid coffee will have aged signs like fading color but this is not really a good indication. 

There are four signs to tell if your coffee is rancid are the:

1. Taste Of The Coffee 

2. Smell Of The Coffee

3. Crema Of The Espresso

4. Coffee Degassing Rate

Here, we are going to tackle these four factors with the following questions. But before that, here’s a mandatory Caffeine Dojo’s illustration on how to tell if coffee is rancid.

What Does Rancid Coffee Taste Like?

Rancid coffee tastes nothing like fresh coffee. More often than not, rancid coffee tastes relatively flat with no depth of flavor and sometimes carries an unpleasant distinctive sour taste.

However, this must not be confused with highly acidic coffee which could be the properties of the coffee itself.

So, to make sure that you will be able to tell what rancid coffee tastes like, you first need to experience the taste of freshly brewed coffee. In essence, there are many variables that affect the taste of coffee. But generally, it can be a combination of either nutty, fruity, bitter, earthy, etc. 

What Does Rancid Coffee Smell Like?

If your coffee beans smell like old musty cardboard it has most likely gone rancid. Rancid coffee has none of the fragrance of freshly ground coffee. 

To give you an idea of what fresh coffee smells like, simply just walk into a high-traffic cafe and get a whiff of the aroma surrounding the cafe. The smell of lightly caramelized nut that fills your nostrils as you anticipate your morning Americano is the smell of fresh coffee. 

In rancid coffee, most of these aromatic compounds have already long escaped from the coffee beans. Furthermore, the oils in the coffee bean start to degrade releasing an unpleasant stale aroma.

How Does Crema Of A Rancid Coffee Look Like?

The third way to quickly determine if your coffee is rancid is simply by looking at the crema of your espresso shot. If you didn’t know already, an espresso is divided into three parts;

1. Crema

2. Body

3. Heart

In this case, we are interested in the crema, which is the topmost layer of the espresso. When you brew espresso with fresh coffee grounds, you will notice a distinct golden creamy layer of foam resting on top of the espresso shot. Think of a good pour of Guinness. 

And what if you brew espresso with rancid coffee?

The very first physical characteristic of the espresso that you will notice on the espresso is the lack of the crema layer. This tells you that your coffee has been sitting around for far too long. Flavor-wise it has an unpleasant sour taste and it is definitely not suitable for any espresso drinks. 

Barista tip! Sometimes the lack of crema on your espresso shot is not just because of rancid coffee, instead, it may be probably due to poor extraction of your espresso. 

How To Determine An Overly Degassed Coffee From Its Packaging?

The final way to tell if your coffee has probably gone rancid is by looking at your bag of coffee.

First of all, coffee beans have trapped gasses (mostly carbon dioxide) in them during the roasting process. So naturally, these gasses would eventually escape from the coffee bean to the atmosphere. And for this reason, you can often find one way valves on coffee beans packaging.

However, if the rate carbon dioxide gas removal from the valve is slower from the rate of carbon dioxide gas generation from the coffee beans, you will find the coffee bean bag to look extremely bloated.

This is one tell tale sign to tell that the coffee beans may have been sitting on the shelf for a long period of time.

Other Ways To Detect Rancid Coffee

Other than the four main ways to tell if your coffee has gone rancid, you can roughly gauge if your coffee has gone stale or rancid simply by referring to the expiry date and roasting date of the coffee. 

Expiry Date

Like all consumables, there is a ticking time bomb until the end of its shelf life. 

Generally, consuming coffee beans past their expiry date will not cause any major issues but be prepared for flat and boring-tasting coffee. 

Roasting Date

Coffee roasters and manufacturers will always stamp the roasting date of the batch of beans on the packaging. Generally, you will want to consume the coffee a week or two after the roasting date to allow the coffee to rest. 

From this point, consuming the coffee further away from the roasting date will increase the chances of your coffee going stale or rancid.

Why Does Coffee Go Rancid?

Now that we have answered the question of how to tell if coffee is rancid, next you should know why coffee goes rancid.

The main reason that coffee goes rancid is due to a process called oxidation. Coffee beans consist of various oils and flavor compounds that define the characteristics of the coffee itself. Once you open the bag of coffee, this introduces air and exposes the coffee beans themselves to oxygen. 

Without proper storage (i.e. an airtight container in this case), the continuous exposure to air will slowly oxidize the flavor compounds in the coffee and at the same time, aromatics will seep out of the coffee. 

For this reason, coffee roasters and manufacturers will often nitrogen-flush and seal the coffee bags to eliminate the presence of oxygen in the coffee bean bag. Also, coffee will need to rest to release trapped carbon dioxide gas. Hence, you will usually find the coffee packages fitted with a one-way valve too. This way, carbon dioxide from within the bag can escape the coffee package but air cannot enter it. Clever!

How Long Before Coffee Turns Rancid?

Like all food products, the food quality will slowly degrade over time. Naturally, the further away from the preparation date where you consume it, the worse the quality will be.

Hence, the same principles apply to coffee beans. 

To give you a general idea of how long coffee beans’ freshness lasts (with proper storage conditions!): 

• Whole Coffee Beans (Unopened Package): 3 Months 
• Whole Coffee Beans (Opened Package): 1 Month
• Ground Coffee: 1 Week
• Instant Coffee: Depending on the manufacturer, it can usually last from 6 months to 2 years although technically, its shelf life can be way longer. So the next time someone asked “Does instant coffee go bad?”, you should know that they are built to last. 

Author’s Note: I have also published an extensive post on why you should choose whole coffee beans over ground coffee!

That said, this is only a rough estimate of a typical coffee bean’s lifespan in terms of freshness. Hence, manufacturers and roasters will most often use the nitrogen flushing technique to preserve the freshness of the coffee. However, once you open the packaging, I’d highly recommend you consume them

Nonetheless, always refer to the expiry date on the package!

What Can You Do To Prevent Rancid Coffee?

The bad news is you cannot prevent coffee from turning rancid. The good news is, you can delay your coffee from turning rancid by storing your coffee properly. Ultimately, you would want to reduce the exposure of the coffee beans from the three main culprits that cause coffee to turn rancid. These three culprits are:

• Oxygen
• Moisture
• Sunlight

Fortunately, all three factors can be put under control with proper storage conditions. So, by simply putting your coffee beans in an airtight container and placing it in a dry area with no sunlight exposure, your coffee beans will generally remain fresh longer.

Also, there are plenty of myths circulating the internet about freezing coffee beans. I personally do not advocate for this process as thawing coffee beans will cause condensation resulting in wet coffee grounds. 

If you do, I’d highly recommend you consume them quickly after thawing and not freeze them again as this will cause icing on the coffee beans. 

What To Do With Rancid Coffee?

It is sad to know that a good bag of coffee has gone rancid and it is certainly a waste to simply just dispose of them. So what to do with expired ground coffee or whole beans?

First of all, DO NOT JUST THROW AWAY OLD COFFEE! 

Even though the rancid coffee beans are not good enough for your cup, there are simply many many ways you can repurpose them. 

1. Composting

Coffee beans are organic items and these are a perfect addition to your plant compost. However, before you go on mounting coffee grounds on your plants, you first have to find out if your plant thrives on nitrogen-rich soil or carbon-rich soil. 

If it is carbon-rich soil, you are good to go. That said, moderation is key!

2. Eliminates Odor 

If you have old coffee beans sitting around, I’d highly suggest you grind them up and dry the coffee grounds in the oven (try not to burn them!). Then place them in little pouches and knot them up. Place them in your car or room, because ground coffee is a great odor absorber.

Not only do you not need to use air fresheners, your place now smells like coffee! How cool is that?

3. Natural Exfoliator

Coffee grounds are actually really good exfoliants to remove dead skin cells. 

Forget the overpriced exfoliators we find in the market, if you have old coffee grounds, I will teach you a simple hack to save you some money. 

– All you have to do is mix equal parts of coffee grounds, sugar, and coconut oil, and viola, a fancy exfoliator mix at a fraction of the cost. 

– Rub the mix all over your body and let it marinate your skin for about 5 minutes. 

– Rinse the coffee mix and notice the radiant look on your skin. 

4. Hair Growth

Hair loss is a real problem and it is a problem that will affect most of the global population. Research reveals that a certain hormone called dihydrotestosterone (DHT) is responsible for balding. 

However, you will be pleased to know that a study in 2007 shows that caffeine stimulates hair follicles growth; resulting in thicker luscious hair. 

Time to take a warm shower with a bucket of Americano?

If you are interested to know what else to do with old coffee, check out this extensive list we have on other uses for old coffee!

Can You Drink Rancid Or Expired Coffee?

A question that I often get is, “What happens if you drink expired coffee?”

Visually, if the coffee beans are not moldy and rotting away on your countertop, I would say it is okay to consume them although I don’t recommend it. The flavors of the coffee will definitely be off but will most likely not cause you to be ill. 

Personally, I too have accidentally drank expired coffee once upon a time. If my memory serves me well, the coffee flavor is pretty flat and just bitter. Fortunately, nothing bad has happened to me other than getting a slightly uneasy stomach.

Anyway, I would still highly recommend you get a fresh batch of coffee beans because life is too short for bad coffee.

FAQs About How To Tell If Coffee Is Rancid

What does rancid coffee smell like?

What does rancid coffee smell like? Rancid coffee’s smell can best be described as dusty, mildewy, or flat.

Can rancid coffee make you sick?

Is it safe to drink expired coffee? We have good news and bad news. The good news: No, coffee doesn’t really “go bad” in the way that bread grows mold or a banana slowly rots on your countertop. And drinking coffee made from old beans won’t make you sick, even if the expiration date has passed.

How do I know if my coffee is expired?

Using your nose is the best way to tell if it has gone bad. If coffee has gone bad, the pleasant aroma will be gone and with it much of the taste. Using this coffee will not harm you, but will just not have much flavor if the smell is gone. It may also lose its deep dark color and appear a lighter brown.

What does spoiled coffee taste like?

Sour coffee comes down to two things: (1) bad beans and (2) bad brewing. If the beans are under-roasted, they’ll taste grassy and sour. If they’re old and stale, they’ll have a really sharp lemony flavor.

Does Ground Coffee Go Bad?

Like whole coffee beans, ground coffee will not go bad. However, without proper storage, they will lose flavors and go stale. The main difference between whole coffee beans and ground coffee in this case is that ground coffee will go stale way faster. This is because ground coffee has more surface area exposed to air. 

Conclusion

Now that you know how to tell if coffee is rancid, it is time to clear out this coffee from your pantry. But remember do not just dispose of these old coffee beans because you may still find plenty of uses for them. 

Most importantly, plan the purchase of your coffee supply (whole beans not ground coffee!) to ensure you always have fresh coffee. As I always say, life is already as hard as it is, it does not deserve a bad cup of coffee. 

If you find this piece of article informational, please do share it with your fellow friends. baristas and home brewers!

Happy brewing!