How storage effects the freshness of coffee

Many key coffee aroma compounds are known to be unstable [Blank et al. 2002, Monro et al. 2003] and/or highly volatile [Yeretzian et al. 2003, Pollien et al. 2003]. As soon as they are formed during the roasting process, they begin to break down and evaporate. The loss of freshness is driven by two main mechanisms:

• Volatilization of highly volatile aroma compounds.

• Chemical reactions, such as oxidation with O₂ or intrinsic interactions between coffee’s constituents.

Numerous chemical compounds—including thiols, diones, aldehydes, and vinyl derivatives—can react with each other during storage, further altering the aroma profile.

FACTORS AFFECTING COFFEE STABILITY

Oxygen : Exposure to oxygen leads to the oxidation of aroma compounds and lipids, resulting in a loss of flavor and freshness. Studies show that during long-term storage, roasted coffee undergoes compositional changes due to oxidative processes.

Temperature : High storage temperatures accelerate oxidation and the breakdown of volatile compounds. The loss of aroma from coffee beans roughly doubles every 10 °C increase in temperature.

Humidity : Coffee is hygroscopic, meaning it readily absorbs moisture from its surroundings. Excess moisture can trigger microbial changes and increase the risk of mold formation, both of which compromise coffee quality.

Light : Light exposure, particularly UV radiation, can induce photochemical reactions in coffee beans, leading to the degradation of key aroma compounds. Research indicates that prolonged exposure alters the coffee’s chemical composition, negatively impacting its flavor.

BEST PRACTICES FOR COFFEE STORAGE

• Use airtight containers : Minimizing exposure to oxygen slows oxidation and helps preserve aroma compounds (Gloss et al., 2014).

• Store in a cool, dry place : Keeping coffee at low temperatures and humidity levels reduces the risk of chemical degradation and microbial growth. A cool, dry environment away from heat sources is ideal.

• Protect from light : Coffee should be stored in opaque containers or dark locations to prevent photochemical degradation.

• Prefer whole beans : Since ground coffee has a significantly larger surface area exposed to oxidation, it is best to store whole beans and grind them just before brewing.
  
  

Following these scientifically backed storage recommendations helps maintain coffee’s quality and freshness for a longer period, ensuring a superior flavor experience.