How to Make and Use Freeze Dried Coffee

As the second most popular drink worldwide after water, more than 1.6 million cups of coffee consumed every day. Some people drink their flavorful coffee as a morning boost, while others can drink all day long.

Nowadays, coffee is not only a beverage but is a culture, a comfort, and a daily essential for countless individuals worldwide. While some people consider the sourcing, roasting, brewing and consumption of coffee as a whole, many others aim for convenience and quick consumption.

Imagine a process that transforms your favorite brew into a lightweight, shelf-stable, and easily transportable form without affecting its rich aroma and robust flavor. That's the magic of freeze dried coffee, a technique gaining popularity for its preservation prowess and convenience. In this article we will discover advantages, production and usage of freeze-dried coffee.

Advantages of freeze dried coffee

Taste and flavor are very important when it comes to enjoying a cup of coffee. The loss of aroma and flavor substances that are formed during the roasting process and transferred to the water during the brewing process negatively affects the enjoyment of coffee. Therefore, a durable coffee product should have minimal impact on these components.

Freeze drying allows coffee to retain its natural flavors and aromas because it is carried out at low temperatures. Indeed, when you prepare a cup of coffee using freeze-dried granules, you can expect a rich and strong flavor that rivals freshly brewed coffee.

Spray drying, another method used in the production of soluble coffee. As a result of the heat, some of the aromatic substances unique to coffee are lost, and chemical changes can occur in the flavor substances. Therefore, there can be significant differences compared to freshly brewed coffee.

In addition to the flavor advantage, freeze-dried coffee also has an impressive shelf life. Unlike other types of coffee, which can become stale or lose their flavor over time, freeze-dried coffee can be stored for much longer without compromising on quality. So whether you are an occasional coffee drinker or a devoted coffee enthusiast, the long shelf life of freeze-dried coffee makes it a convenient and reliable choice.

1. Taste and flavor

For coffee lovers, taste and flavor are paramount. Industrially, 2 methods are widely used in the production of soluble coffee. Therefore, there are dozens of studies on how these methods affect the aromatic profile and sensory properties of coffee. The general conclusion of these studies is that freeze drying provides a much higher quality product than spray drying.

Indeed, the high temperatures applied in spray drying (typically higher than 300ºF) cause many aromatic compounds to volatilize and disappear. Moreover, these temperatures trigger some reactions in the product, such as the Maillard reaction. This results in a change in the sensory flavor.

However, freeze drying is carried out at gentle drying conditions and therefore has minimal impact on the aroma and flavor profile of the product. This allows for the preservation of delicate flavor profiles that may be lost through other processes.

Studies on coffee chemistry show that roasted coffee beans contain more than 800 volatile compounds. However, 117 of these compounds were found in coffee brew. In one study, it was observed that aromatic component retention varied between 60% and 80% depending on the concentration during spray drying at low temperatures.

In a 2015 study, the effects of spray drying and freeze drying processes on aroma in soluble coffee production were investigated. According to the results of this study, aroma retention was 57% in spray drying and 77% in freeze drying.

Another advantage of freeze-dried coffee is that it provides a consistent flavor across different batches. This consistency is highly valued by coffee lovers who appreciate the ritual of preparing and enjoying a cup of their favorite brew.

Overall, freeze-dried coffee offers a wide range of flavors to satisfy even the most discerning palates, from dark and earthy notes to subtle hints of fruit or chocolate.

2. Shelf-life

Products made durable by freeze-drying have an impressive shelf life. Due to the fact that chemical reactions are not triggered during the process, freeze-dried coffee can last for 3 to 5 years when stored under suitable conditions.

On the other hand, soluble coffee produced by spray drying has a shelf life of 1 to 2 years. These products are more exposed to aroma and flavor changes due to ongoing chemical reactions during storage.

3. Health benefits

Coffee offers a range of health benefits due to the bioactive components it contains. These effects are often due to the phenolic substances and antioxidants found in coffee. Some of these benefits include:

• May reduce the risk of type 2 diabetes
• May support brain health
• May promote weight control
• May be associated with reduced risk of depression
• Supports the liver and can protect it against diseases
• Supports heart health
• May increase longevity
• It may improve athletic performance.

The majority of studies observing these effects have been carried out directly with freshly brewed coffee. For soluble coffees to have the same effect, these valuable components must be preserved without damage during processing.

In one study, the phenolic content of coffees brewed with a percolator or coffee maker was 2-3 times higher than soluble coffees. However, the method by which instant coffee was obtained was not reported in this study.

According to the Pubmed database, some of the health benefits associated with freeze-dried coffee consumption are as follows:

• Anti-tumor effect against breast cancer cell lines
• Positive effect on certain gut bacteria and HDL
• Supporting weight loss but also aggravating cholesterol

4. Preparation

The preparation of coffee drink using freeze-dried coffee does not require any special equipment such as pressure machines and percolators. By simply mixing the desired amount of granules into hot water, you can prepare your coffee easier and quicker. This makes it an ideal and economical choice for many people.

How is freeze dried coffee made industrially?

Freeze dried coffee is made using a unique process that starts with perfectly roasted and ground coffee beans. The first step involves brewing a strong and concentrated coffee under pressure. This brew generally have low dry matter content. To decrease the cost, the brew is concentrated under vacuum upto 50 brix (soluble solid content). Then this concentrate is frozen to form ice crystals as a thin layer using a belt freezer. In the freezing step, low temperatures such as -40ºF was used to form small ice crystals. The thin ice layer is broken into small pieces using a mechanical grinder and spread onto trays.

The trays are loaded to freeze dryer and the process is started. Sublimation occurs under carefully controlled conditions of temperature and pressure. The result is coffee that retains its original flavor, aroma, and color, with almost all the moisture removed.

How to make freeze dried coffee at home

Although it is widely available in the stores, of course you can transform your own favorite coffee into freeze-dried coffee and store it for several years.

• Step 1: Brew your coffee powder but make it much strong and concentrated than usual. The higher the concentration, the lower your production cost and the more product you get.
• Step 2: Cool down the brew (preferably quickly) and pour them to the freeze dryer trays evenly
• Step 3: Freeze the trays at least 4 hours.
• Optional step: Rapidly break the ice crystals into small pieces (Make sure that no melting occurs at this stage)
• Step 4: Run your freeze dryer to let it cold and ready
• Step 5: Load the trays and let it dry for at least 20 hours.
• Step 6: Check the coffee's dryness. If necessary, hold in freeze dryer for several additional hours.

Freeze dried vs spray dried coffee

Freeze dried coffee and spray dried coffee are two common methods used to prodcuce instant coffee. While both methods remove moisture to create a convenient coffee product, there are some key differences between the two.

One significant difference lies in the process itself. Freeze drying involves freezing the brewed coffee and then slowly removing the water through sublimation. This method helps to preserve the aroma and flavor of the coffee while creating a granular texture.

On the other hand, spray drying involves spraying a fine mist of brewed coffee into a hot, dry chamber. The water quickly evaporates, leaving behind small coffee particles that dissolve easily in water. This process tends to produce a more powdery texture and may result in a different flavor profile.

Another difference is in the final product's shelf-life. Due to the freeze-drying process, freeze dried coffee generally has a longer shelf-life compared to spray dried coffee. This makes freeze dried coffee an ideal choice for those who want to stock up on their favorite coffee or for situations where freshness is important. However, spray dried coffee is still considered to have a decent shelf-life.

It must be noted that, energy requirement for spray drying of coffee is lower than that of freeze drying. Therefore, spray dried instant coffees are cheaper than freeze dried ones.

How to store freeze dried coffee

The best option for storing freeze dried products are air tight containers such as Mylar bags, mason jars or vacuum packagings. If you plan to store for an extended periods such as 3-5 years, it is logical to use oxygen absorbers and store in a dark place.

Best conditions for long term storage are lower than 75ºF and humidity under 40%.

How Long Will Freeze-Dried Coffee Last? Technically decades under ideal conditions. But, since it is an aromatic product, there is general aggrement on 3-5 years.

Frequently asked questions

What is the difference between freeze dried coffee and instant coffee?

The instant coffees we see in the markets can be produced by two different methods: namely freeze drying and spray drying. Generally freeze-dried instant coffee are granul shaped and expensive than the spray-dried counterparts.

Is freeze dried coffee the same as spray dried coffee?

No, freeze dried coffee and spray dried coffee are different methods of producing soluble coffee, each with its own characteristics. Freeze dried coffee is made by freezing brewed coffee and then removing the water through sublimation, which results in a superior flavor and aroma.

Spray dried coffee, on the other hand, involves spraying a fine mist of coffee extract into a hot air chamber, where the water evaporates, leaving behind coffee particles. While spray dried coffee is also soluble and convenient, it tends to have a milder flavor and aroma compared to freeze dried coffee. Ultimately, the choice between the two methods depends on personal preference and the desired coffee experience.

Can coffee be freeze-dried?

Can coffee be freeze-dried? Yes, coffee brews directly or after concentration can be freeze-dried and stored for several years.

How long does instant coffee last?

How Long does instant coffee last? Freeze dried instant coffee last technically decades under ideal conditions. But, since it is an aromatic product, there is general aggrement on 3-5 years. On the other hand, spray dried coffee has a shelf-life up to 2 years. Instant coffee must be stored in a cool place (lower than 75ºF) and away from moisture

Is instant coffee freeze dried?

Is instant coffee freeze dried? Yes, but only for some products. The instant coffees we see in the markets can be produced by two different drying methods: namely freeze drying and spray drying. Generally freeze-dried instant coffee are granul shaped and expensive than the spray-dried powders.

Where to buy freeze dried coffee?

• Grocery Stores: Most grocery stores have a coffee aisle where you can find different brands of freeze-dried coffee.
• Online Retailers: Websites like Amazon, Walmart, and specialty coffee retailers often have a wide selection of freeze-dried coffee brands that you can order online.
• Coffee Shops: Some coffee shops and cafes also sell freeze-dried coffee.
• Specialty Food Stores: Stores that focus on gourmet or specialty foods sell freeze-dried coffee along with other premium coffee products.

Is there caffeine in freeze-dried coffee?

Yes, freeze-dried coffee also contains caffeine but generally slightly less caffeine than ground coffee. Caffeine levels in a cup of ground coffee range from 70 to 140 milligrams per cup, compared to 30 to 90 milligrams in one teaspoon of freeze-dried coffee.