Instant coffee is made by extracting brewed coffee, then drying it to create soluble coffee crystals or powder.
Here's a breakdown of the process:
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Extraction:
- Ground, roasted coffee beans are extracted with hot water in semicontinuous or continuous extractors. Think of this like brewing a very strong, concentrated pot of coffee.
- The coffee extract produced typically contains 20–25% solids.
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Concentration (Optional):
- The extract may be preconcentrated to contain up to 60% solids. This step isn't always necessary, but it can improve the efficiency of the drying process.
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Drying: This is the key step that turns liquid coffee extract into instant coffee. There are two main methods:
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Spray Drying:
- The coffee extract is sprayed as a fine mist into a stream of hot air.
- The water evaporates quickly, leaving behind tiny, dry coffee particles.
- This method produces a finer powder.
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Freeze Drying (Lyophilization):
- The coffee extract is frozen into a thin slab or granules.
- The frozen coffee is then placed in a vacuum chamber.
- Under reduced pressure, the ice sublimates (turns directly into vapor) without melting.
- This process preserves more of the coffee's flavor and aroma, resulting in a higher-quality instant coffee with a coarser texture.
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Agglomeration (Optional):
- Some manufacturers "agglomerate" the fine spray-dried powder, creating larger granules that dissolve more easily and resemble freeze-dried coffee. This involves re-wetting the powder to make it sticky, then drying it again into larger clumps.
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Packaging:
- The dried instant coffee is then packaged in jars, packets, or single-serve containers.
In summary, instant coffee production involves brewing concentrated coffee, and then using either spray-drying or freeze-drying techniques to remove the water and create a soluble product.
