I made a starter a week ago last Saturday with the intent to brew last Tuesday. Needless to say, it didn't happen. I did not airlock this starter and the Erlenmeyer sat on the kitchen counter covered with tinfoil. I observed a health krausen and there appears to be no signs of infection. Just the reside on the glass on some clusters of bubbles in stasis on the top of the beer.
After one week, is my starter still good? I have another vial of WPL01 in the fridge but I'd prefer not to use it unless I have to.