More starter woes

[Bru]

Yesterday I boiled 7L water and 700g DME to step up my 4L and 2L starters (2308 and 2124). After cooling the wort and adding it to the yeast already in the Erlenmeyers I opened the kettle to find 8L of wort left (I started with 7L and had decanted it). I checked gravity and the remaining wort was 1.019.
I had accidentally opened the ball valve when putting ice packs into the water bath when I was cooling and water (clean but not boiled) had poured into the pot from the water bath.

My main concern is obviously infection.
If an infection is pending - how long will it take to show itself ?
Is it possible that the infection only shows itself once the started has been pitched (I plan on pitching on Sunday) ?

I adjusted the water pH to 4 before boiling the wort. Im hoping the vigorous fermentation in the starters will knock out any infection.

 

[Suthrncomfrt1884]

I don't think you should worry too much. If you get it fermenting nicely, it should eat up any infection that's starting. If you do have an infection, it probably won't show for at least a few weeks. I've only had one infection before and it didn't show up until after 3 weeks in primary. Even then it was just getting started.