Question about yeast starters, simply for the pursuit of knowledge.

[SteakW]

So I was wondering, why is adding DME to a yeast starter recommended/necessary while adding table sugar to "proof" the yeast is considered unnecessary/a hindrance? Basically, how is adding DME to the starter not the same as proofing the yeast? Thanks.

 

[frazier]

Evidently, the yeast that will propagate in a sucrose environment do not handle maltose well, or at all. You want to proof the yeast with the food they'll be eating.

 

[BrewCrewKevin]

Exactly. DME will be the same mix of glucose, sucrose, maltose, and fructose as the wort will have. So conditioning them to that environment is beneficial. If you just add sugar, primarily sucrose, then the yeast doesn't adapt well for other sugar chains.

 

[IL1kebeer]

In addition to what the others have said, in a high simple sugar environment, yeast will lose the ability to produce the enzyme that breaks down longer chain sugars such as maltose and maltotriose, and apparently this can happen after only 1 cell division. Anyway, this pretty much means that you will have major attenuation problems when this yeast is pitched into wort.

 

[Calder]

You make a starter for liquid yeast to build up the population.

You proof dry yeast to rehydrate it ready to work. The higher gravity of a sugar solution is not as good as water at this stage.