Re: In frying bacon the fat turns white and goes 'snap'. Why?

When you heat bacon, the first steps that occur is the coagulation of the 
protein in the meat portions and then the boiling off of the water present.

Water occurs with the protein in the meat portion, and also in small 
amounts in the fat portion where the connective tissue structure holding 
the fat cells together exists.

When the water in the fat starts to boil, gas cells are formed which alter 
the optical properties of the fat (scatter, rather than transmit), thus 
causing the 'translucent' fat to scatter more and appear whiter.

When sufficient energy at a spot has been transferred to the gas cell to 
break the mechanical strength of the boundary, it explodes with a snap-
crackle-pop.

Once all steam stops rising from bacon, you can raise the temperature 
dramatically higher, until the fat starts boiling. At this point, the 
bacon will 'foam' and crackling will drop way down. You could reduce the 
heat significantly at this point, since water has a much higher heat of 
vaporization than the fat. Beware of fire at this point!