What is yeast?

What is yeast?The answer is simple: yeast has a cellular nucleus containing its DNA in the form of chromosomes, which is not the case of bacteria. Yeast is a living organism. Like those found in humans, yeast cells are living and natural.
Small but powerful
Small but powerful

The yeast cell is no bigger than a pinhead. Zoom onto the infinitely small.

Yeast is an egg-shaped microscopic cell, not visible to the naked eye.  It is scientifically called a "micro-organism".
Its size does not exceed 6 to 8 thousandths of a millimetre, which is hardly bigger than a pinhead.
It is commonly found in the form of a block of yeast. A 1 cm cube weighs around 1g and contains more than 10 billion living yeast cells!

Natural and chemical?
Natural and chemical?

There are two types of yeast: natural and chemical. They are not the same thing! Explanations.

There are natural and chemical yeasts. Chemical yeast consists of bicarbonate of soda, potassium hydrogen tartrate and corn starch and does not allow fermentation.
Natural yeast consists of living elements and is used to make bread, wine, beer and even vaccines.

What a swell yeast it is
What a swell yeast it is

The name "yeast" comes from the fact that these organisms make the bread dough "foam or froth". How does it work?

Yeasts create what is called a fermentation. In this case, it is alcoholic fermentation as glucose (sugar) is transformed into carbon dioxide and alcohol. The released carbon dioxide gives the sparkle to beer and makes bread dough lighter, more airy and therefore less compact.