First brew with process changes, low FG...interpretation

[Wyobrew22]

Hi all....I moved to a smaller place and sold my previous brewing setup. I had done a couple of batches with some very basic equipment here and was not happy with the final product so I upgraded equipment a bit with a new chiller, kettle and an aquarium pump/stone aeration setup. Here is what's happening with my first batch at the 5 day mark. I formulated a quick recipe for a mostly Irish red with a bit of rye and what I had laying around:

8lbs. great western 2-row
12oz. Caramunich
4oz. Roasted barley
1lb. Flaked Rye
153 degree single infusion BIAB mash
1.25oz. EKG@60min.
.75oz EKG@10min.
whirfloc (first time using, looked gross but the beer seems much clearer than my usual)
Properly re-hydrated Nottingham yeast, temp controlled at 61-62 degrees
expected OG 1.048, measured 1.047 (probably from the additional cooling water added)
expected FG 1.010, measured 1.004

I mash with full volume (7.5gal.) and control mash temp with an immersion circulator. I messed up this time a bit and overheated my strike water...the mash was tied in the bag for about 5-7 minutes at right around 160 degrees before I got the circulator on and cooled quickly to desired mash temp. Mashed for 50 more minutes at 153. I was worried about the enzymes and conversion but have clearly fermented out pretty well. Fermentation was quick and what I would call moderately active with really good churning action but low/moderate krausen. Is it normal for Notty to drop to that low of a final gravity? I'm sure I will get my process more accurately dialed in within another batch or 2 but I'm wondering how this one will turn out. Should I leave it on the yeast much longer with how far it has dropped, or keg sooner and try it?

 

[ncbrewer]

I've never gotten that kind of attenuation with Nottingham, but I don't think it's considered impossible. My guess is that it's finished and taking it off the yeast or not won't make any real difference - unless it turns out to be infected. How does it taste?

 

[Wyobrew22]

I just pulled another sample and think it actually tastes pretty good...malty, a little rye spice. I am planning on leaving it on the yeast until day 9 or 10 when I will have time to brew again, no harm in letting it sit a few more days, it will still be the fastest grain to glass beer I have brewed. Muuuuuch cleaner tasting at this point than my last few batches, I’m going to attribute it to way less kettle junk getting into the fermenter and a cooling to pitch temp time that was about 1/3rd of what I had been working with.

 

[kh54s10]

FG numbers in a recipe are just a prediction. I am surprised with your warm start of the mash that it went that low but I only get concerned when more that 10 points off. And then I am more concerned with being too high rather than too low. I also never even check for final gravity until at least day 14. I know that some will check for final gravity at 5-7 days and package soon after but I don't believe that is best practice. YMMV.

 

[bmaupin]

I wonder how accurate your thermometer is ... that might account for the low fg.??

 

[Wyobrew22]

It is a digital quick read from my restaurant, and it matches the readout on the immersion circulator. When I got it secured and turned on (I leave the unit off the kettle for the pre heat) it read 160 which I checked with my thermo, the time was a rough estimate at 5-7 minutes though, it may have been less. I really need to fabricate something more reliable to hold my circulator at the proper level in the kettle so I don’t have to mess with it.

 

[ncbrewer]

Having two thermometers that give the same reading gives me some confidence, but it's really best to calibrate. You can calibrate by checking at the boiling and freezing points of water. Values in between can be interpolated. Note that the freezing point check is tricky. Use crushed ice packed into a Styrofoam cup. Put it in the fridge until enough melts to put the thermometer to the required depth. This was in an on-line BYO article -
http://byo.com/departments/item/412-calibrating-thermometers-techniques ,but it's no longer available on line.