[The Leaven – exploring the relationship between science and religion (cont)]
The term leaven originates from the latin word levere, the French equivalent being the noun levure meaning to rise. The English term yeast, probably originates from the Greek term for fermenting which was zestos. Derivatives from later European influences resulted in the medieval English terms zeest, which eventually became yest.
Fermentation procedures and the art of making leavened bread was first introduced by the Egyptians over 4000 years ago. In ancient Egypt, brewing and baking were practiced together on the same premises. Wooden and plaster models depicting Egyptians working in a brewery and bakery have been recovered from a tomb dated around 1975 BC during the reign of Amenemhat I. Egyptian hieroglyphs that show pictures of dough rising next to bread ovens have also been found. The Egyptians were therefore aware that both processes used the same substance.
To the Egyptians, bread was an important commodity used as a type of currency for trading and for the payment of services. In fact, the workers who built the pyramids were believed to have been paid in bread. Bread was also used to pay homage to Osiris the God of grain. The Egyptians believed that Osiris had given them the gift of leavened bread to make it lighter to carry, especially in the journey to the afterlife.
In contrast to the Egyptians who revered fermented dough, the ancient Palestinians were extremely suspicious of it. Perhaps this could be due to the different methods by which the bread was leavened. Palestinians would reserve a piece of leavened dough from a previous baking to make the next batch of bread. This dough could easily have been contaminated by harmful microbes which may not have been completely destroyed by the baking processes. If a person died all leaven was thrown out of the house and from all neighbouring houses because Palestinians thought that it may have contributed in some way to the individual’s demise, they believed that the angel of death may have thrust his sword into it.
In Britain during the 15th century, as in ancient Egypt, brewing also took place on the premises where bread was baked. The thick layer of dormant yeast cells that sank to the bottom of the brewing or wine vessel was usually referred to as the lees, while froth from the top of beer was known as barm. Barm from a good batch of beer would be reused to make more beer and to ferment bread dough. Barm, the brewer’s equivalent of leaven, used to be referred to as Godisgoode because it was thought to be a gift from God. Yeast used in brewing and baking seemed to be received in a different manner to leaven that was used to make sourdough. In fact during the 17th century the Paris Faculty of Medicine tried to ban leaven because in the New Testament St. Paul had signified that it was a substance that denotes corruption.
So it seems that fermentation generated through leaven was not viewed in the same way or as a similar process to the fermentation that produced wine. It is clear from passages in the Bible that leaven is used figuratively to symbolise the permeating influence of certain types of human behaviour, especially corruption. Traditionally unleavened bread is used to symbolise the purity of Christ’s body whereas wine symbolises the blood of Christ. This is not without some irony, as wine is made in a similar process and perhaps more likely to lead to acts of sin and corruption when consumed than is bread. Indeed, some religions do recognise this and at the beginning of the 20th Century, alcohol became prohibited for a time in a number of Nordic countries and North America due to Protestant led objections. Alcohol is also prohibited in some countries that follow Islamic laws. The contradictory views relating to fermentation in wine and bread will be discussed at greater length in a later chapter.