The word "yeast" comes from the Sanskrit 'yas' meaning "to seethe or boil". Yeast is a living organism and is in the air around us. It is a member of the fungus family and is a single-celled fungi of which there are about 160 different species. Baker's yeast as well as brewer's yeast belong to the Saccharomyces cerevisiae species. Louis Pasteur in the 1850's is credited with first discovering and understanding the fermentation process which led to the development and cultivation of the yeast we use today.
Baker's yeast, like baking powder and baking soda, is used to leavened baked goods
(breads, Danish pastries, brioche, croissants). The difference between these two leaveners is that baking powder/soda react chemically to produce the carbon dioxide that makes the baked goods rise. Yeast, on the other hand, is a living organism and the carbon dioxide it produces is the result of the yeast feeding on the dough.
Here is a definition from dictionary.com.
leaven
–noun
1. a substance, as yeast or baking powder, that causes fermentation and expansion of dough or batter.
2. fermented dough reserved for producing fermentation in a new batch of dough.
3. an element that produces an altering or transforming influence.
There are two types of leaveners.
- yeast - a living organism, creates carbon dioxide by feeding on the dough
- baker's yeast - react chemically to produce the carbon dioxide and makes the bread rise
Just like other Christians, I have been wondering about yeast for a long time. Then last week as I came across a messianic website . God told the Israelites to get rid of the baker's yeast, a chemical reaction to cause baked goods rise, which is called khametz in Hebrew. It is any flour of the five species of grain, mixed with water and allowed to ferment before being baked. The five species of grain are wheat, spelt, oats, barley, and rye. Khametz, in reality, comes from a root which means "to be sour", according to Refiner's Fire (above mentioned website).
Then I suddenly remembered about one evening around 1988!
A friend of mine came over to give me something in a container. I cannot remember what she called it, but it was a bread starter. It was like some bread dough in a small container. She told me to use it to bake some bread and to save a portion of the new batch before I baked a loaf of bread. She said that this bread dough started long ago (sort of like chain letters??) and it hadn't been broken. She wanted me to give the saved portion to someone else so that the next person could do the same and give a new portion to another person. Just like #2 of the Dictionary.com definition:
2. fermented dough reserved for producing fermentation in a new batch of dough.
It looks like Amish people do this.
I am not starting any new religion by posting this, but I think now I can understand the concept of starting a brand new batch...without using a little batch (bread starter) from the old batch and mix it into the new batch. This was the beginning of the new life for the Israelites. God didn't want them to bring the old customs and start a totally new batch! I suspect if this was one of the reasons why God said:
They were to be cut off from the community of Israel! God was very strict about this. God wanted to end the life in Egypt, the old life, for the people.Exodus 12:19 (New International Version)
19 For seven days no yeast is to be found in your houses. And whoever eats anything with yeast in it must be cut off from the community of Israel, whether he is an alien or native-born.
It can be said about us, too. Just like we are made a brand new christian when we believe in Jesus, the old cannot be there. We are brand new, born again. We took off our old clothes and wear a new one. New bread needs a brand new ingredients, not to be mixed with the old. To me the concept of 'old' can be better understood with the 'bread starter' method because if the yeast is everywhere in the air, I wouldn't know which one is old.
Matthew 16:5-6 (King James Version)
5And when his disciples were come to the other side, they had forgotten to take bread.
6Then Jesus said unto them, Take heed and beware of the leaven of the Pharisees and of the Sadducees.
Here's my thoughts. My friends' bread starter got started long time ago and it continued, adding little more of the new batch. Jesus didn't want us to continue our old way like Pharisees and the Sadducees' traditions. The law ended when Jesus came.
Galatians 3:19 " Why, then, was the law given? It was given alongside the promise to show people their sins. But the law was designed to last only until the coming of the child who was promised. God gave his law through angels to Moses, who was the mediator between God and the people."
Our Father is so wonderful. He wants to make us brand new. Jesus made it possible.