they need heat or sunlight
Plenty of moisture, carbohydrates and moderate temperature
Yeast needs warmth, food and moisture to grow while bacteria needs warmth, food , correct ph,oxygen, and time to grow. Moulds need warm, moist conditions and viruses need time and opportunity for the conditions to be right for them to thrive.
Yeast need warm temperatures in order to grow. The perfect temperature for yeast is about 110 degrees F. Yeast will not start to reproduce and rise without warm temperatures to activate it.
Yeast needs water, food (in the form of sugar) and heat to grow. It does not need oxygen and can grow quite well under anaerobic conditions. The presence of oxygen during fermentation can actually favor the growth of other microorganisms that will compete with the yeast.
ANY plant needs SUNLIGHT to grow. we cant do without sun. Except for the creatures at the sea bottom.
try agar search google for "potato dextrose yeast agar recipe"
it needs sun light and heat
Warm water is best for yeast because yeast is a living organism that likes to live in similar temperatures to humans. Put yeast in hot water and it dies, put it in cold water and it will not do its job properly (will be too cold to reproduce fast etc). Put it in water that is just right and it will thrive
Sugar is a necessary food source for yeast to grow and ferment. When yeast consumes sugar, it produces carbon dioxide and alcohol, which are responsible for fermentation in bread-making and alcohol production.
Yeast Grows much better in sugar water. They are micro organisms that need the sucrose in the sugar to activate and grow, without the sugar very little would happen. If you used salt water it would most likely kill the yeast.
A chicken and some chicken feed