How old can a starter REALLY be?
Couple of other threads are branching off into discussion of the yeast Saccharomyces cerevisiae. I thought therefore I would open a new one for better organisation and focus of topic.
I want to ask, just how old can one claim a flour-water "starter" to be?
First a couple of factoids about Saccharomyces cerevisiae.
1. The yeast cells double every 90-100mins or so
2. The mean life span of a cell is 26 generations
http://mic.sgmjournals.org/content/153/11/3667.long [1]
http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae [2]
100min x 26 = 2600 mins which is 43 hours which is just short of 2 days.
Like our own human bodies, every cell that makes us what we are, dies off in time, but thankfully the cells are replicated before that happens. The replication time for our various cells varies tremendously but it is believed that the cells with the largest replication cycle are 10yrs. The implication of this is philosophically intriguing. It means you are no older than 10yrs no matter how old you believe you are, or at least there is no cell in your body older than 10yrs ! A counter philosophical thought is that everything that is "us" is made up of matter, and since matter can neither be created nor destroyed then all the matter that makes up our bodies has been here since the dawn of the universe itself, in which case we are many billions of years old.
What we choose to define as the "human being" defines how old we are. If it's our cells, then we're 10yrs old, if it's the primordial matter, then billions of years old.
And so back to wild yeast starters and our good friend Saccharomyces cerevisiae.
If each yeast cell lives no longer than a couple of days, how in any true and just sense could it be said that there exists a "20 yr old grandmother starter"? In looking for possibilities, I wonder whether this refers to some other elements of the starter that actually ARE 20 yrs old or is the whole notion simply a lot of kidology and hocus pocus?
Consider this. I light a wood fire in the chimenea in my garden and feed it with a constant stream of new fresh fire wood. For 20 years I keep it going and never once let the fire go out. Tell me, is my fire 20yrs old? Is there any part of it that is truly 20yrs old? It has had new fresh wood constantly, and new fresh oxygen constantly, so surely the flames I am seeing are new fresh flames and all the gasses and products of combustion are equally being given off freshly. Nothing in there is 20yrs old unless perhaps the ashes produced linger on for that length of time (but then do the ashes constitute the fire?).
I'm intrigured by this notion of these very old starters given that any starter is a symbiotic balance of yeasts and bacteria that are constantly fed, which replicate for a finite number of generations and then die.
Common sense says there must be "something" in these starters aside from the yeasts and bacteria that does somehow survive through the years or else it's all a bit disingenuous.
Can anyone tell me what that "something" is?
EP