Sunday afternoon I added lacto to my wort after boiling for 5 minutes and then cooling to 90 degrees. The instructions say to let it sit for one to three days and it is day three now and there is only about a tear drop size of white bacteria forming on the top. I know you can check the ph balance but I don't have means of doing this today and I also took a small sample and would like it to be more sour than it is. I have also kept the the wort at a constant 75-79 degrees.
So my question is, should I wait for an entire blanket of white to form over the wort or should I just go ahead and brew it up as is?
Thanks in advance