parallax roasting_FASA

There are two types of coffee roasting machines :

With Rotating Drum This formula is based on an operating principle:

  • Conductivity with convection
  • Roasting by direct contact of the walls of the drum, heated by the flame with the flow of hot air.
  • The roasting time varies between 8 and 17 minutes.

Fluid This formula is based on an operating principle:

  • Switching heat
  • Hot air flow, allowing more identical firing temperature control and precise synchronization.
  • Roasting time varies between 8 and 17 minutes.
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Roasting Analysis

The heat used in roasting causes the coffee beans undergo changes such as:

  • Reduction of moisture (from 12-8% to 5-1%)
  • Reduction in weight (15 to 20% due to water evaporation)
  • An increase in volume (by 30 to 60% due to the formation of carbon dioxide)
  • Color change (the grains are brown-skinned) change in content (+12 -16% fats, -10% sugars – acids 3%)
  • Development of fragrances

These changes are gradual and are determined by the increase in firing temperature.

  • 50 ° C: internal modification of tissues begins
  • 60 ° C: the evaporation process begins
  • 100 ° C: first color changes come about
  • Between 150 and 180 ° C: stage light roasting
  • Between 200 and 230 ° C: optimal degree of roasting
  • Between 215 and 220 ° C: light roasting (more acidic and less bitter)
  • Between 220 and 225 ° C: medium roasting step
  • Between 225 and 230 ° C: dark cycle (bitter and less acidic)
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Cooling Methods

After roasting, coffee beans are rapidly cooled to ensure internal condensation of aromatic substances.

 There are two methods of cooling:

Air cooling

  • Cold air flow, rapid cooling.
  • Loss of some perfumes.
  • Produces fumes

Water Cooling

  • Thin spray in precise quantities.
  • Reduce several perfumes by opening the pores of the fruit of the coffee.

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