Why are most food chains limited to three to five trophic levels?

Most food chains are limited to three or five trophic levels because the energy available is only enough for those number of trophic levels: there is insufficient energy to go round more trophic level. At each trophic level, a large quantity of energy is used to maintain organisms at that level, because of this, organisms at one trophic level, pass less energy to the ones at the next trophic level. 

Fermentation

Explanation:

Fermentation is the process whereby carbohydrates are converted to acohol or acid by the activities of some enzymes. During the process of fermentation, carbon dioxide is produced and it is found as tiny pockets of air inside the bread dough. This make it to rise. The alcohol produced evaporates later during the bread making process.