Very fast fermentation for Kölsch!

[Grant2]

This is my second BIAB brew (have been doing extract before this) and I'm getting a really fast fermentation on the Kölsch I made on Sunday.

Brew session info:
https://www.brewersfriend.com/homebrew/brewsession/302983

The fermentation graph starts recording at ~9PM on Sunday, but I technically pitched the yeast at 2PM. Didn't sort out the connection between Tilt and BrewersFriend until I was done cleaning.

Here I am 4 days later and the beer is at FG.

I'm using Wyeast 2565 (Kölsch) that I did a yeast starter with (~2 liters).

I did a pretty fine crush on my grains, my mash temp started at 149.5 and was at 143.4 after 90 minutes.

Pre Boil Gravity was 1.040, Post Boil Gravity was 1.062.

I'm not complaining about the quick fermentation, just wondering what could have contributed to it. Maybe i had too big of a yeast starter? I did a 1.5x pitch rate.


Thanks

 

[BOB357]

My ales often reach final gravity in 2 to 4 days at 66 degrees. An adequate pitch of healthy yeast and aeration/oxygenation are both important for healthy fermentation. Healthy fermentations are usually marked by quick starts and shorter fermentation times.
Temperature can also come into play. Higher temperatures = faster fermentations as a rule, but can also produce off flavors.

I noticed the difference in your pre and post boil gravities is a lot more than I generally see. Do you cool your samples or correct for temperature? I've found that temperature correction charts tend to be less accurate as you get farther from the calibration temperature of the hydrometer.

 

[Grant2]

Thanks for the feedback, looks like I'll be making sure to do a good yeast starter on all of my brews going forward!

I'm fermenting at 60F as it's a Kölsch.

Yeah, I'm not quite sure what's up with my pre and post boil gravities. I made sure to cool the samples down to what my hydrometer is calibrated for (60F). I'm still dialing in what my boil off rate is (though it was 1.25 gal/hr, will probably increase that to 1.4-1.5 gal/hr). I ended up with 4.8-4.9 gallons post-boil, but that was fine as I added my yeast starter in to bring it up above 5 gallons. I would have preferred 5.5 gallons post boil, so I definitely need to increase my starting water volume.

My grain crush is pretty good, but I'm also looking at motorizing my mill to do a easy double-crush.

 

[GFHomebrew]

I noticed that too 22 points off the boil gee wizz boy! When I brew I take a 250ml sample into a glass pyrex jar and pop that into the freezer It's usually not ready for a reading until around end of boil. Post boil sample after cleanup

You can use the hydrometer temp calc on this site too if you know the wort reading temp.

 

[Grant2]

Yeah, I'm not sure why my numbers are so far off. I make sure to get a gravity reading at the temperature that my hydrometer is calibrated for.

 

[Mark Farrall]

As Bob already mentioned it's probably more a sign of a good fermentation. Apart from the yeast angle you also may have made a more fermentable wort than you were expecting. Maybe a longer or lower temp mash?