Green coffee can remain of good quality for up to a year after being harvested, provided the conditions are favorable. The lifespan of an animal can be shortened by poor environmental conditions, but it can also be extended by some techniques that help the animal live longer.
This is an important point to consider because green coffee beans can actually stay fresh for a much longer time than most people realize, and without becoming dangerous to consume. Coffees that have been aged are not as popular with specialty coffee roasters as they used to be, but they are still common practice in some circumstances.
Specialty roasters usually focus on two things: how recently their coffee was roasted, and how recently the beans were picked.
It is very important for roasters to store green coffee properly in order to preserve quality. It is important to store coffee in a way that will protect its quality and flavor.
Storing green coffee badly can make it more likely to suffer physical damage and lose its original flavor. Problem areas that roasters commonly face and how to overcome them using best practices.
1. Temperature
The temperature of the environment where green coffee beans are stored is important for quality control. Green coffee is particularly sensitive to high temperatures, as the fragrant aromatic compounds and flavors can evaporate. High temperatures can cause moisture loss, which contributes to loss of flavor complexity over time.
Low temperatures can also be problematic. It’s generally better to store coffee at cooler temperatures, but freezing green coffee can create some difficulties.
Coffee that is not properly packaged and frozen can develop ice crystals. This affects the coffee’s cellular structure. If you want to freeze your coffee, vacuum seal it before freezing. Once thawed, use the coffee immediately as it can lose quality quickly when returned to room temperature.
It is generally accepted that the best temperature for normal warehouse storage is between 50 and 75 degrees Fahrenheit.
2. Humidity
The humidity and temperature of a green coffee can have a significant impact on its quality. The amount of moisture in coffee beans can be affected by the humidity of their environment. High humidity may cause the beans to absorb moisture, while low humidity can cause them to lose it.
Mold and other microbes can grow in high humidity environments, which can be dangerous for green coffee. Therefore, it is best to avoid such environments. The key to success with this metric is moderation. A usual range of 50-70% relative humidity with moderate temperatures is the accepted standard.
The International Coffee OrganizationIf provides evidence from scientific studies to help support the coffee consumption boundaries it has set. Cups will not grow mold at 70% relative humidity or below.
If the relative humidity is above 80%, the risk factors for hygienic storage increase significantly and fungi can grow.
The relationship between humidity and temperature is complex and worth investigating further. Relative humidity is when we talk about the amount of moisture in the air in relation to how much moisture the air can actually hold.
If a coffee is stored in conditions where the temperature is not stable, then the relative humidity will also change.
The coffee beans may dry out if the warehouse temperature rises during the day and there is no new humidity source.
The goal of good green coffee storage is moderate and stable temperature and humidity.
3. Packaging type
Coffee beans are typically shipped in jute bags or other plant-based materials such as burlap or sisal. The fibrous material is not very good at protecting green coffee beans during shipping and storage, but it is cheap and easy to make.
Recent innovations in coffee packaging have replaced plant fiber sacks completely.
Two of the most popular types of plastic-type bag liners are GrainPro and Ecotact. These liners are inserted into jute packaging or may be used at larger scale to line an entire 20’ container.
The plastic used for coffee packaging is often multi-layered to allow the coffee to breathe while still protecting it from the environment. There is evidence from both experiments and personal stories that supports using this type of liner to keep green coffee physically and sensory fresh.
This type of packaging helps prevent organic materials from being lost during shipping conditions that are less than ideal and may extend the amount of time that a coffee can be stored before it goes bad by several months. It’s important to tie the semipermeable bag tightly if you don’t use the full amount, because an open GrainPro bag won’t work as intended.
Some common packaging solutions for green coffee beans include paper liners for jute bags or jute replacement options like polypropylene (plastic) and vacuum sealed bags.
If you vacuum seal green coffee, it will preserve the quality and prevent it from losing moisture. However, you should use the coffee within a few days of breaking the seal, just as you would with green coffee that has been thawed and then frozen.
Some coffee roasters prefer to store their green coffee beans in storage bins. Bulk storage options, such as silos, can be convenient for storing large quantities for long periods of time.
Smaller containers such as plastic Cambros or bins can help keep leftovers from a roast for the next day, and can be fitted with casters for ease of mobility.
Storage bins that are not airtight can still provide some level of protection, but they should be insulated for best results.
If you store your green coffee in a facility where food or beverages are served, you may be required to keep the green coffee in its original packaging or use food-grade containers with clear date labels, depending on your local regulations.
4. Shelving and pallets
Coffee bags can be stored on shelves or pallets. Storing coffee bags on shelves provides a number of advantages for roasters.
Large quantities of coffee can be moved through a warehouse quickly and easily using forklifts. This “first in, first out” approach helps to keep the coffee fresh and maximizes the use of space.
A pallet can be used to store coffee bags in a convenient and space-saving way by stacking them off the ground.
The Green Coffee Association has issued a resource that outlines some best practices for food service and handling that can be employed at any warehouse size. They recommend the following:
- Keep coffee off the floor, a minimum of 4 inches.
- Keep the pallets clean.
- Keep coffee 24 inches (two feet) from walls and ceilings.
- Store coffee so that at least two sides of each bag are available for inspection and sampling.
- Maintain 20 inches between coffee piles.
In addition, certified coffees (such as organic coffees) will require separate and labeled storage areas to maintain their certification. Different storage containers must be used for organic and conventional coffees. Organic coffees cannot be stored in containers that have been used for conventional coffees.
5. Pest control
Pests are a problem for coffee that is stored and must be controlled. Prevent infestations by not providing opportunities for pests to enter your home, like repairing holes in your walls and cleaning up spills on the floor.
Rodents and insects are a serious threat to health and safety and should not be ignored.
A pest control professional can help you if you have an infestation. Organic coffees should not be exposed to certain treatments and chemical solutions should be avoided around all coffees.
Phases of processing and storage
Drying and hulling
It is initial important to remove excess moisture from wet processed green coffee as it comes out of the fermenting tank, this is especially true for the moisture that is lodged between the parchment and green bean.
, causing the coffee to spoil After the initial stage, if coffee is dried too quickly, two problems can occur: (1) the outside of the bean shrinks and it becomes difficult for moisture to move inside the grain, and/or (2) too much heat is absorbed and the protective parchment cracks, causing the coffee to spoil.
DAMAGE PREVENTION TIP: Keep an eye on the temperature to avoid any damage to your coffee beans. As they dry, they tend to heat up more quickly. The fading of color is called “bleaching.”
As mentioned earlier, the moisture content in green coffee beans is an average of the moisture content of beans with different physical properties. Slow drying is the best way to avoid a wide range of moisture contents so that the moisture of different sized beans will evaporate more uniformly and beans can exchange moisture.
It’s still possible for some beans to retain moisture content higher than 12% even when coffee is dried at the proper temperature, which can result in wet spots. The flowers of these plants tend to bleach over time, and they can also cause a defect called “cardenillo,” which is caused by micro-organisms that leave a yellowish-reddish dust.
Storage in parchment
In countries where food is grown, it is well-known that storing it in parchment paper will preserve its flavor over time. This is most likely because parchment paper reduces the amount of moisture, oxygen, and temperature that the food is exposed to. The respiration process is general to all seeds.
Coffee is unique in the way that it shrinks and changes heat and mass transfer due to the presence of parchment.
The parchment prevents the green beans from absorbing too much moisture by being hygroscopic.
Seeds in storage for a shorter time in parchment have higher germination rates. Seeds that have been stored in parchment for a shorter amount of time have a higher germination rate.
A number of studies have found that coffee beans gradually lose their flavor over time, due to changes in their metabolic reactions or other chemical processes.
Coffee in parchment form lasts longer than green coffee. 50% of green coffee becomes unusable within the first 3 months, whereas 50% of coffee in parchment form is still usable after 1 year.
The polyphenol oxidase enzyme, which is responsible for the blue-green color in green coffee, becomes inactive after the coffee beans lose their viability. This means that the color of the beans can be used to determine how long they have been stored.
A test to see how good the coffee quality is, is to germinate some of the seeds and see how many of them grow.
C Coffee can stay good for five months if it has a moisture content of 15 to 18 percent humidity and is kept in conditions of 5 to 15 degrees Celsius. Green coffee should be stored in a cool, dry, and well-ventilated area with a temperature of 15-20 degrees Celsius and a relative humidity of 35-55%. These conditions, however, are unlikely for green coffee storage and transport.
Local humidity and temperature can fluctuate, which adjustments in the roasting process. Coffee storage and transport can be less controlled and may fluctuate due to local humidity and temperature, which can then adjust the roasting process. The stability of coffee is determined by how it is packaged and stored initially. Different conditions of temperature and humidity will cause the coffee to change.
If the coffee beans are still in a state of respiration, they need to be put in a cool, ventilated area for a period of time to reduce the respiration rate.
The temperature fluctuates often, and this causes problems. The equilibrium moisture content of green coffee increases as the temperature decreases, and the total moisture and water activity of green coffee increase as the result of condensation.
The temperature of both the environment and the coffee itself must be kept low in order to slow down coffee metabolism.
If the temperatures are alternated between hot and cold, moisture can condense on the outside of the bean. The bean should not be exposed to a high level of humidity, as this can lead to mold formation.
Temperature changes cause the relative humidity inside a storage space to rise.
C (77 ?F) and 50 ?C (122 ?F). The coffee was tested at 80%, 87%, and 95% relative humidity at 25 degrees Celsius (77 degrees Fahrenheit) and 50 degrees Celsius (122 degrees Fahrenheit). C. . A second test was conducted where the temperatures alternated between 14 degrees and 25 degrees. C every 12 hours.
No condensation was observed on the samples kept at a constant temperature, but it was observed on samples kept at alternating temperatures.
There was a consistent increase in moisture levels at all three humidity levels, though the rate of increase was greater at the higher humidity levels.
After 15 days of storage, there was a significant difference between samples maintained at the constant temperature and the alternated temperatures, with the alternated temperature showing greater moisture loss.
Evaluation of damaged coffee
The evaluation of damaged coffee is done in order to figure out (1) what kind of damage there is, (2) how much damage there is, and (3) where the damage came from. When judging the quality of coffee, you should consider factors such as how much mold or insect damage there is, the color, and how good it tastes.
The color of moldy beans varies depending on the mold, from black mildew to white, grey, or greenish. Most insect damage to coffee is of the type illustrated in coffee defect posters.
after drying. Coffee that is discolored or has lost its flavor may have been damaged by exposure to moisture or heat, especially if it has been stored for a long time or if it has been re-wetted after drying.