Most of my brews are still done with packaged yeast, because I'm too lazy & cheap to do all the stuff necessary to liquid yeast lol
Anyway, I finally got reliable fermentation. Previously I've seen ferments that take as long as 72 hours to start, and then go soo slowly it might as well be lagering. I've also had ferments that start within 12 hours. And I've had everything in-between.... and that's with everything being roughly equal at the start of pitching the yeast! I'd always done it according to the directions, which say pitch it and then stir it in after 10 minutes or so.
Well, last week I accidentally left the yeast on top of the wort for an hour prior to stirring it in. And that ferment began vigorously bubbling the airlock four hours later. So I tried it again with today's brew. Sure enough, within four hours the fermentation takes off and is gurgling vigorously even as I type this.