Aeration of Starter,...NOT Wort,...Jamil ?

[jamilz]

I came across an interesting paper from the MBAA, volume 40, issue 4. It is all about pre-oxygenating yeast and not adding O2 to the wort.

The net result is more esters and higher alcohols with pre-oxygenation.

[J.Brew]

So..

[J.Brew]

I came across an interesting paper from the MBAA, volume 40, issue 4.

The net result is more esters and higher alcohols with pre-oxygenation.

So if your concerned with yeast by products, esters from cell reproduction within oxygenated wort would be less of a concern than esters production caused by oxygenating a starter according to these findings? Or am I misunderstanding...

At the risk of sounding like an idiot, Whats the MBAA?

[Speyedr]

Master Brewers Association of America - I Googled it


Glorpidy Glorp Glorp!!

[J.Brew]

Looks like I studdered!

[Norwalde]

"The SG of the starter wort is a balancing act. The lower the SG, the easier it is on the yeast. However, there comes a point where you don't really get enough growth to make it worthwhile. If you're starting out with a trashed yeast (like from a bottle conditioned beer from Belgium) you should start at 1.020 (5 Plato). However, if you're interested in building up a vial of White Labs or an XL pack of Wyeast, you should target 1.040 (10 Plato). It just isn't worth the trouble otherwise as you'll get very little growth. "

What about the volume stepping process as opposed to adding the yeast straight to the target volume (say 2 Liters)? If the yeast are reproducing to an optimal concentration, why step the volume? Does too low a concentration stress them, or what?

In particular I'm interested in this because my only locally available liquid yeast is Wyeast Propogator packs (25b cells) as opposed to the Activator packs (100b cells). I'm wondering if I need to start with a smaller volume starter and work up to my target.

Thanks to the Pope and Eric for a great discussion!