Repsol YPF

Breadmaking

With homemade breadmaking, gas is used only in the baking step. However, with handmade pastries and cakes, gas fuels a number of accessories such a cream cookers, burners, griddles, etc. These are the steps of the process: 

The following processes are carried out during the “baking” step:

• Heating the centre of the loaf of bread from 28°C to 100°C, supposing the centre is 80% of the bread’s weight and its specific heat capacity is 0.6 kcal/kg °C.
  
• Heating the crust from 28°C to 230°C, supposing the crust makes up 20% of the bread’s weight and its heat capacity is 0.6t kcal/kg bread.
  
• Evaporation of 0.43 kg of water that is initially found at 28°C.
  
• Energy used to carry out the respective transformations for starch hydrolysis and coating the crust in caramel.
  
  

  During baking, the speed at which heat is transmitted to the product depends on the oven’s temperature. However, as the baking proceeds, the characteristics of the crust are modified. Since heat passes through the crust, heat transmission depends not only on the temperature of the oven but also on the state of crust formation.  As the crust dries, and with it, the parts near the crust, the heat transmission coefficient decreases. Consequently, the real speed at which heat moves to the centre also decreases. Steam created in the oven at the beginning of the baking phase delays the drying out of the crust, thereby improving its thermal transmission coefficient and shortening the baking process. 

  The size of the pieces to be baked is a very important factor in choosing the temperature of the oven and how long the baking will last. A high temperature, which heats up the centre of the product more quickly, could burn the crust. A low temperature, used for small pieces, could create large pieces with centres that are not completely cooked.