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How to Keep Coffee Fresh

A study by the National Coffee Association revealed that 62 percent of Americans drink coffee daily, and out of these, 79 percent brewed the coffee at home. This study shows that a majority of consumers appreciate the process of preparing their coffee. 

While roasting and brewing at home gives you control of the flavor and aroma of your coffee, keeping your coffee fresh is equally necessary to enjoy the great taste. In this article, we explore the factors that affect the quality of your coffee in storage and how you can keep it fresh for the best home brewed cup. 

Why Does Coffee Go Stale? 

coffee beans in a cup

Air, temperature, moisture, and light are the main factors that affect the quality of your coffee while in storage and cause it to lose its freshness. It also compromises the taste and aroma of your beverage. 

Coffee beans can go bad quickly when exposed to moisture, and it is why keeping coffee in the freezer may not be the best idea if you are not using a tightly sealed bag. When exposed to air, ground coffee can saturate, which causes it to clump and lose its aroma. On the other hand, heat and light cause moisture loss that can make the coffee lose its taste. 

Coffee, like good wine, should be stored in an airtight container and kept in a cool and dark place until you need to use it. Below are some tips that will help you keep your coffee fresh while in storage. 

Avoid Bulk Buying

The best tasting coffee is freshly roasted, ground, and brewed when the flavors and aroma are still intact. However, it is not always possible to have this process for a fresh cuppa, and we frequently have to store our coffee in between the steps. 

One way to avoid wasting good coffee is by buying small amounts that get consumed quickly. Pre-ground coffee stays fresh for a week, and roasted coffee beans can keep slightly longer, while green coffee beans can keep up to a year when stored properly

Store in an Airtight Container

different roast coffee in coffee jars

Air is one of the key factors that contribute to your coffee going bad. Poorly sealed containers can expose the coffee to humidity which makes it crystallize and lose its flavor. On the other hand, the coffee may lose some moisture to the air if kept warm, which causes it to lose its aroma and taste. The sealed containers should also be opaque to prevent light penetration that can affect the flavor of your coffee.

Every time you open your container to measure out the beans for grinding or brewing, a small amount of air enters the container, which may hasten the degradation of the coffee. Vacuum sealing your coffee in small batches may be a better option for containers because it allows you to store dry ingredients such as coffee in the fridge or freezer without the risk of moisture penetrating the bag. 

Other options that work just as effectively include Mylar bags that are ideal for long-term storage and valve sealed bags that are great for storing freshly roasted coffee beans. 

Ground coffee is even harder to keep fresh. To know how to properly store them, check out our tips on storing ground coffee

Effect of Light and Heat on Coffee

Generally, the oils, proteins, and enzymes in the beans that determine the attributes of the coffee become unstable during the roasting process. The effect of UV light from the sun or the typical light bulbs on roasted or ground coffee speeds up the chemical breakdown of these compounds and spoils the beans.

On the other hand, exposure to heat, whether sunlight or increased room temperature, will cause the oil inside the coffee beans to rise to the surface, which ruins the flavor. Therefore, it is advisable to store coffee in an opaque container and ensure that the environment is cooled.

How to Store Ground Coffee

ground coffee in a pan

Although whole beans stay fresh longer than ground coffee, many coffee enthusiasts still prefer buying grounds because they are easier to prepare. Another advantage is that you will find more variety with grind sizes and roast levels than if you were buying roasted coffee beans. However, pre-ground coffee goes stale much faster than whole beans because it has a larger surface area to absorb or lose moisture. 

Factory ground coffee is often packed in vacuum-sealed packaging to prevent moisture, but it is not ideal for long-term storage once you open it. On the other hand, if you buy coffee grounds at the supermarket, you can opt to vacuum seal with FoodSaver bags to keep it fresh for up to six months. Vacuum sealing also allows you to keep the coffee grounds in the freezer because it removes the air inside the bag to prevent condensation, and prevents moisture from seeping in. However, it is not advisable to refreeze the coffee once you open the bag, so you may need to pack in single use batches.

Alternatively, you can keep the coffee in an airtight container to preserve the freshness. However, this method only keeps the grounds for about a week before going stale, so you should only buy what you need for this period to avoid wastage. The containers should be solid ceramic or glass to prevent light from damaging the coffee and preserve the taste. 

What Is a Coffee Bloom? 

Coffee bloom is the best way to determine if your ground coffee is still fresh or stale. It occurs when you pour a little hot water on coffee grounds to accelerate the release of carbon dioxide and cause the water to foam. The bloom process occurs in the initial stages of brewing and usually lasts for several seconds. If your coffee does not bloom, it may indicate that most of the gas has already expelled, and the grounds are stale. 

Coffee bloom enhances the taste of your coffee because the hot water makes the coffee particles expand and release carbon dioxide and other molecules that determine the flavor of your cup of Joe. It is the main reason why you should let your coffee bloom for about 20 seconds before you stir the mixture. Bloom occurs in any brew method that uses fresh coffee, but it will vary depending on the brewing method.

However, several factors can impact the occurrence of bloom. These include poor storage conditions that cause the coffee to degas much faster, different roast levels where dark roasts have less carbon dioxide due to the duration of the roasting process, and the origin of the beans.

How to Store Roasted Coffee Beans

It is considerably easier to keep coffee beans fresh for longer than grounds and is the best option if you prefer buying your coffee in large amounts. You could also opt to get unroasted beans which can stay up to a year when stored properly. However, roasting coffee beans at home may take more time and effort compared to buying roasted beans. 

Another reason to consider is that beans will produce carbon dioxide in the first few days of roasting and may produce a sour brew. The degassing period varies with the roast profile, where darker roasts release the carbon dioxide gas faster and the coffee variety.

Apart from carbon dioxide, freshly roasted beans are saturated with sensitive aroma compounds, which get easily degraded when exposed to air and heat. Aroma and taste are the key attributes of coffee that indicate whether a particular batch of coffee is fresh or stale.

Air also causes oxidation of oils in the coffee bean that may produce an acidic brew. While storing your roasted beans in the freezer will slow down the degradation process significantly, it may also affect the taste and get spoiled by condensation. However, you may consider vacuum-sealed or valve-sealed bags for freshly roasted coffee instead of using containers to prevent moisture from creeping in. 

How to Determine if Your Roasted Beans are Fresh?

Coffee beans contain a mixture of molecules that contribute to the aroma and flavor of the coffee when brewed. When roasted, the beans excrete an oily substance called coffeol, which coats the beans and gives them a glossy appearance. However, the amount of coffeol on the beans depends on how long it took to roast the beans, and dark roasted beans will have more shine than light roasts. 

Another way of determining the freshness of your beans is to smell them. Fresh coffee has the best-smelling aroma, and studies have shown that smelling coffee may have almost the same effect as drinking it to stir you up in the morning. However, the aroma and flavor will deteriorate as time goes by, which is one of the reasons why you should always buy enough to consume quickly.

When you roast whole beans, they emit carbon dioxide in a process known as degassing, which occurs in the first few days of roasting. Factory roasted beans are usually packed in one-way, valve-sealed bags that allow the gas to escape while preventing air from entering the bag. If your coffee does not come with a valve-sealed bag, it probably means that the beans are stale, and there is no degassing happening.

However, if you buy your roasted beans at a local store, you can do a simple degassing test to see if the beans are fresh. If you leave a few roasted beans in a Ziploc bag overnight, the bag should puff up if the beans are still degassing. On the other hand, the bag will not expand if the beans are stale. 

How to Store Green Coffee Beans

Green coffee beans are stable and therefore are the best for long-term storage. However, you will have to store them like roasted beans and ground coffee in a dark and airtight container away from heat. Another option is to use Mylar bags to protect the beans from light with oxygen absorbers that remove air and moisture inside the bag to keep them fresh. 

Mylar is a polyester film with high resistance to light, air, and moisture and is the ideal packaging bag for long-term storage. It works similar to vacuum bags like FoodSaver except that it blocks out light which can cause your beans to go rancid. On the other hand, you can opt to use oxygen absorbers with heat sealing the Mylar bag instead of vacuum sealing and get the same effectiveness in storing your green beans for up to several years. 

The flipside of storing green coffee beans is that you will roast and grind them yourself when prepping your cup of coffee. Although the roasting process may take a lot of effort, with trials and errors, until you get the hang of it, it is also a personally rewarding experience that allows you to develop a brew that is suited to your tastes. 

How Long Does Brewed Coffee Stay Fresh? 

Generally, coffee will not taste as good if you leave it out for long because it oxidizes and tastes bitter. If you have brewed a lot of coffee and you do not want it to go to waste, there are a couple of tricks you can use to keep it fresh until you can drink it later on. 

To begin with, you should pour your coffee into a flask to keep it piping hot while preventing oxidation. Brewed coffee will stay fresh for up to 30 minutes in your cup, two hours in a flask, and several hours in the refrigerator. However, the taste will be noticeably different the longer it stays, while additives such as creamer, milk, and sugar will also determine how safe it is to consume.

Final Thoughts

Green coffee beans are by far the easiest way to keep your coffee fresh for any amount of time. However, most people would prefer not to roast the coffee beans at home, while others prefer buying pre-ground coffee and instant coffee. Roasted whole beans will keep for a couple of weeks while ground coffee will stay fresh for about a week, after which it begins to lose taste. However, you can store green coffee beans for up to a year without going bad. 

Whichever way you decide to keep your coffee, the main reason why your coffee will spoil is exposure to air, light, or heat. We recommend investing in airtight jars or FoodSaver bags with vacuum sealing that you can keep in a darkened space in your pantry. 

However, the best method that we can recommend would be Myler bags that are light and moisture resistant with oxygen absorbers to remove air to keep your coffee fresh. Furthermore, you can seal Myler bags with a hot iron, and they allow you to keep your coffee in the freezer to extend the storage period.

Avatar for Giada Nizzoli

Born in Italy but currently brewing from the UK, Giada is a highly-caffeinated coffee expert with a soft spot for espressos. She worked in cafés for years and has recently fallen in love with the practical Kalita Wave (just don’t tell her Italian moka pot!).

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