Aerating wort and starters

[RobMT]

If I've read and understood the many topics related to aerating wort, the idea is to introduce oxygen to be used during the reproductive stage of the yeast life cycle.

This seems to be a crucial element in getting a good, healthy and active yeast. Once reproduction ends, then the fermenting phase begins.

My question is in regards to the use of starters. The idea behind starters (again, if I've understood the literature correctly) is to pitch the correct amount of yeast cells to the wort so it can immediately begin fermenting in the primary, and leave all the off flavours produced during reproduction in the starter vessel.

So if a starter is used and the correct amount of yeast is pitched, just how crucial is aerating the wort at that point?

Thanks in advance for any replies.

 

[NordeastBrewer77]

when you shake, swirl or stir plate a starter, o2 will be introduced giving the yeasties the oxygen they need to reproduce. it's why we don't airlock our starters.
areating or adding o2 prior to pitching a starter isn't necessary, as they'll get o2 ever time you shake the starter. hope that helps.

 

[RobMT]

That's exactly what I was looking for. Thanks for the help and apologies if I made my first post a little unclear.

Cheers!

 

[BradleyBrew]

I would 100% aerate your starter before pitching the yeast. Why not??

 

[Golddiggie]

Using a stirplate you're constantly degassing and aerating the starter during the entire process. This allows you to both have the starter finished sooner and make a smaller starter to get the colony size you want (of yeast)...

Personally, I use either a 2L or 3L flask for my starters on the stirplate. I'm about to build another stirplate (purchased my first one) so that I can have two starters going at the same time. I need to do this for an upcoming big beer I'm planning to make.

 

[RobMT]

I would 100% aerate your starter before pitching the yeast. Why not??

The idea of a starter is to skip the reproductive phase of the yeast in the primary so it can go straight to fermentation once the starter is added to the primary? There is no need for oxygen for this stage in the yeasts life cycle, which is why I was curious about aerating prior to pitching a starter of the correct size. I'm fairly new to brewing, so I'm just trying to make sense of all the nuances. This place is a wealth of information.

Edit: Sorry, re-read your post and saw that you said to aerate the starter. I was asking about aerating the wort in the primary.

 

[Golddiggie]

Unless you have access to the lab equipment needed to do a yeast cell count, chances are you won't get the exact count you need for the batch. So, I still oxygenate the wort before pitching the yeast. It won't do any harm, since the yeast will use it for their cell walls, and growth (I'm usually a few tens of billions of cells short) to get the colony up to the size needed.

I don't aerate the starter before pitching due to using a stirplate. Once I turn that sucker on, it's getting aerated constantly. I do cover the flask opening with a piece of sanitized foil, so that it can pull in air.

 

[RobMT]

Right on, that makes plenty of sense. Thanks again!