[MattyAHA]

so i made a yeast starter using wlp830 german lager, im very ocd with my cleaning and sanitizing (so i thought), anyway had it on a stir plate 24 hours then put it in the fridge to settle out. it was in the fridge for 3-4 days before i got to brew, needless to say i decanted and pitched and i don't know why but decided to taste a drop of the slurry that what was left in the flask after pitching and it was tart/sour, im surprised it went sour that quick and probably gonna have a sour pilsner as a result lol , will adding hops to the starter wort give it more protection from souring bacteria/organisms or is it just a matter that my sanitation procedure is not as thorough as i think it is and i need to tighten my belt, thank you

[denny]

Hops will make no difference.  Started often have that kind of taste due to the yeast in suspension.  If I was guessing, I'd say it's fine.

[Robert]

It's fine, I'd bet.  Stirred starter wort always tastes awful because of the metabolism of the yeast; you have encouraged the yeast to maximize growth rather than going through the kind of fermentation that makes good beer.  This is why it's best to decant a stirred starter, and if you're not planning to decant, skip the stir plate.

[jeffy]

I agree with the above two posts.  It is probably a tart flavor from yeast and not actually a sour flavor.

[Slowbrew]

I'll toss in my $.02 worth of agreement. 

My starters, even when they smell great, typically taste awful.  I wouldn't sweat it.  Wait for the beer to finish, I'd bet it'll be fine.

Paul

[jtoots]

It's fine, I'd bet.  Stirred starter wort always tastes awful because of the metabolism of the yeast; you have encouraged the yeast to maximize growth rather than going through the kind of fermentation that makes good beer.  This is why it's best to decant a stirred starter, and if you're not planning to decant, skip the stir plate.

Could I ask you to expand on that please? Thanks!

[Robert]

It's fine, I'd bet.  Stirred starter wort always tastes awful because of the metabolism of the yeast; you have encouraged the yeast to maximize growth rather than going through the kind of fermentation that makes good beer.  This is why it's best to decant a stirred starter, and if you're not planning to decant, skip the stir plate.

Could I ask you to expand on that please? Thanks!

With a starter of any great size, many people don't want to add a significant volume of that stirred starter beer to their wort in case the off flavors come through.  It's less of a problem if either the starter tastes acceptable, or the starter is very small.  Just a matter of personal judgment really.  I don't like adding any "alien" beer to my wort, so I decant no matter what. 

[ynotbrusum]

Also consider the shaken and not stirred method of using a vitality starter where it is all pitched at high krausen and never stirred on a stir plate.

[denny]

Also consider the shaken and not stirred method of using a vitality starter where it is all pitched at high krausen and never stirred on a stir plate.

THIS^^^^

[MattyAHA]

thank everyone for chiming in