Incomplete fermentation?

[oldjetdriver]

I have a 5 gallon extract completing fermentation well short of expected gravity

Other (10 lb 2.4 oz)​

6 lb (59.1%) — Briess Golden Light — Dry Extract — 3.5 °L — Boil — 60 min
3 lb 2.4 oz (31%) — Briess Golden Light — Liquid Extract — 3.5 °L — Boil — 10 min
1 lb (9.9%) — Briess Caramel Malt 40L — Grain — 40 °L — Steep — 30 min

Hops (5 oz)​

1 oz (35 IBU) — Centennial 10% — Boil — 60 min
1 oz (21 IBU) — Centennial 10% — Boil — 20 min
2 oz (14 IBU) — Centennial 10% — Boil — 5 min
1 oz — Centennial 10% — Dry Hop — 4 days

Miscs​

1 items — Yeast Fuel — Boil — 20 min
0.5 items — Whirlfloc — Boil — 5 min

Yeast​

1 pkg — Lallemand (LalBrew) Verdant IPA 77%

Any ideas on what I did wrong

Thanks

 

[DBhomebrew]

Two possibilities. There are likely more.

Is your expectation based on having brewed this recipe before? Recipe software is usually pretty lousy about estimating FG.

I'm guessing you're using a Tilt? They're great for showing trends, but the krausen sticks to it causing a false reading.

 

[mashpaddled]

Am I reading that correctly that your expected FG was 1.017 or 18 and you ended at 1.021? If so, that's not really so much of a difference that you should agonize over the difference. Extracts are notorious for landing at an FG around 1.020, so not too surprised this is where you landed.

I know there can be some issues with FG readings on a Tilt, so you might want to cross-check with a refractometer or hydrometer.

If the beer tastes good, enjoy it as it is. If you feel like it is too sweet or too heavy, you could consider adding sugar and rousing the yeast to try to give the impression of drying it out more, but you run the risk the yeast don't ferment it out and it ends up even sweeter.

 

[DBhomebrew]

If you feel like it is too sweet or too heavy, you could consider adding sugar

This will just increase ABV leaving the current beer at its current FG. Replacing some of the extract in a subsequent batch with sugar will give a drier rendition.

 

[bike2brew]

1st time post, long time lurking. Your extract brew looks very similar to one I have been working with "Dead Ringer" (Northern Brewer). My last batch (1 mini keg, some bottles) started @ ~1.70 and finished @ 1.20 +/- measured w/ a refractometer and hydrometer. It was a bit sweet but not cloying and quite drinkable and got better as it aged past kegging. I modified the recipe slightly w/ 3.5 lbs of pilsen LME. Fast forward today, my current batch is split between 2 fermenters (Day 16) @ 1.014 & 1.017, respectively. This time I followed the recipe without modifications so very similar to the OP except w/ LME. Temperature on the previous batch was ~ 68 F. This time around my avg temp is 65.8 and 65.1, respectively. I don't know if the higher temp was responsible for the 1.20 finish or that it just turned out like that randomly. I think Mash's comment that extracts often finish @ 1.20 is interesting as I have been looking for an explanation on this. So I am curious about this connection, Briess says their LME is 72% ferementable and with US-05 averaging 77% attenuation. How do these variables affect potential FG? Thanks for the feedback.

 

[bike2brew]

Oh, forgot to mention. My current brews are fermenting w/ Tilt hydrometers. A fun upgrade to reinforce the illusion I am brewing like the big boys and that I have some control over my product.

Here's a few photos of the last IPA, my mini-keg system, and fermenter w/ temperature control.