Should I be concerned yet?

I brewed a 10 gal batch of Guinness ( 3rd AG batch) yesterday night and pitched my Wyeast Irish Ale starter that I had made 6 days prior. My Blichmann chiller worked pretty well and the wort came out at about 55 deg f. I didn't think it would hurt to pitch at that temp but 13 hours later there is no activity yet. I'm only concerned because my other 4 previous batches were bubbling vigorously by that point. Am I worried over nothing?

Thanks

They probably decided to take a nap. Bring up the temperature slowly to the low 60s while periodically agitating the fermentor to get the yeast back into suspension.

RDWHAHB and read this....

https://www.homebrewtalk.com/f39/fermentation-can-take-24-72-hrs-show-visible-signs-43635/

Thanks fellas. I had the fermentor in the garage overnight and although I turned the heater on the garage was still only 62 degrees f. I moved it inside and put it in a room with a space heater. I think it I had it too cool for the yeast to wake up. I'll wait. Thanks again.

I wouldn't mess around with that temperature too much. Yes, things will be a bit slower to start up at a lower temperature, but that's fine. Constantly swinging the temp up and down or whatever, during the initial stages of fermentation, is going to cause more problems than it will fix. Get it to your desired fermentation temp (or give it the ability to self rise there) and keep it there.

Warming was the key. Now 24h after pitching it is bubbling like mad.