what's the fastest you had fermentation start?
 

Just brewed up midwest's liberty cream ale which i modified. I had a 1L starter of washed 1056 which i prepped 24 hours prior. I added yeast energizer enough for the full 5 gallons, aerated with the wine whip before pitching and again right after. Airlock activity started within 3 hours... i was shocked.

Dammit.... Thats quick. How strong is that yeast when it is fermenting a batch? Is it an agressive bubbler or a slow consistent plodder usually?
Bob

Based on the amount if yeast you likely pitched that sounds right. Second plus gen yeast are strong!

I've had a bubble or two as quick as two hours with some Bell's I bottle harvested and bumped up 4 times.

3 hours 2 hours 30 minutes it´s nothing i had a beer once that started fermenting 24hs before I even crushed the grain :D:ban:

If you get a good starter going, it'll technically be fermenting before you even pitch, and you can see bubbles less than an hour into it sometimes.

Just be careful about the temperature, in my experience, short lag time = vigorous fermentation = more heat generated.

I have it in my garage with outside temps staying in the 60s to mid 70s during the day and 50s overnight... i would have swamp cooled if temps were higher.

I believe the wyeast 1056 is pretty aggressive normally. It has been bubbling at a fairly steady rate 1-2bubbles/sec

Safale-05, dry yeast - used it twice so far in NB's Pumpkin Smash (OG 1.049) and Black IPA (OG supposed to be 1.069, IIRC; wound up being 1.095 due to not accounting for boil off).

I rehydrated the yeast before pitching, and had fermentation bubbles in my blow off tube about 2-3 hrs after pitching

This statement doesn't make any sense to me. How can the beer be fermenting before the yeast is pitched.

To answer the OP's question, I once had take off in less than hour with a healthy starter.*

*Yes, I see the irony of that answer.