Fermentation Stopped Early - Thoughts?

[zgreenside]

Brewday was 1/17.

Here's the recipe:

8 lbs Pale Malt (2 Row) US (2.0 SRM) Grain 56.1 %
1 lbs Barley, Flaked (1.7 SRM) Grain 7.0 %
1 lbs Caramel/Crystal Malt - 60L (60.0 SRM) Grain 7.0 %
1 lbs Chocolate Malt (350.0 SRM) Grain 7.0 %
1 lbs Oats, Flaked (1.0 SRM) Grain 7.0 %
12.0 oz Munich Malt (9.0 SRM) Grain 5.3 %
12.0 oz Roasted Barley (300.0 SRM) Grain 5.3 %

0.45 oz Magnum [16.70 %] - Boil 60.0 min Hop 23.5 IBUs
0.75 oz Goldings, East Kent [5.60 %] - Boil 10.0 min Hop 4.8 IBUs
1 lb Milk Sugar (Lactose) [Boil for 10 min](0.0 SRM) Sugar 5.3 %

1.0 pkg Safale American (DCL/Fermentis #US-05) [50.28 ml] Yeast

Fermented in a temp chamber that I built that is set to 65F.

Created an oversized starter out a healthy and brand new pack of US-05 (approx. 1.5L), and took 600Ml out to a quart jar to save for the next batch, then used the nearly 1L that was left and pitched it to the wort. Aerated by shaking the bucket for a couple minutes.

I failed and forgot to take an OG...not sure what I was thinking. I did get some readings though:

First runnings 1.054 @ 144F = 12.5qt (3.125g) (Adjusted 1.070)
Second Runnings 1.020 @ 149F = 15qt (3.5g) (Adjusted 1.038)

I had a total of 6.625 Gallons pre boil, 5.5 Gallons post boil. The last batch I made of this beer was slightly different, but I also had .25lb less lactose last time as well.

Now to the meat. Last batch I had was 1.071 OG, 1.018 FG, now I can assume my FG will be a little higher due to the extra lactose, but two readings over a 3 day period had me at 1.030. I'm still hitting probably a 5-5.5%ABV, which is more in style that what it was calculated to be (7.2%), but it just seems off.

Flavor is good, it doesn't seem sweet or unfinished, the krausen fell like it should have, overall tastes great...am I just worrying too much? Should I raise the temp a couple degrees to see if I can kickstart fermentation again or get it to finish up a little?

 

[saccw]

From your measurements, your OG was 1.064. With that recipe, you'd have to hit 80% efficiency to hit that OG, which may be in your normal range. If you're at 1.030 now, you're only at 4.44% ABV, without accounting for the lactose (my copy of beersmith can't account for lactose affecting the gravity but being unfermentable). If it has been stable for 3 days then rousing the yeast may help as will kicking up the temperature.

I don't use dry yeast, but I often read that making a starter from dry yeast will really tire them out by depleting their nutrient reserves.

 

[flars]

Are you using a refractometer or hydrometer for your SG readings? A refractometer will not read accurately with alcohol present in the sample. Take a SG reading with a hydrometer, if you are not using one.

 

[zgreenside]

From your measurements, your OG was 1.064. With that recipe, you'd have to hit 80% efficiency to hit that OG, which may be in your normal range. If you're at 1.030 now, you're only at 4.44% ABV, without accounting for the lactose (my copy of beersmith can't account for lactose affecting the gravity but being unfermentable). If it has been stable for 3 days then rousing the yeast may help as will kicking up the temperature.

I don't use dry yeast, but I often read that making a starter from dry yeast will really tire them out by depleting their nutrient reserves.

I wasn't aware of that, so that may have been what I did wrong. I'll start pitching my dry base starters with some nutrient and see if that helps.
As for the lactose, this is what I was told in another forum: "lactose adds 42 points per gallon per pound. So, if you added one pound to 5.5 gallons, your FG will be raised by 7.6 points"
So my OG would have been closer to 1.072 with the added lactose, and my final gravity should have been 1.023or 1.024 (it was 1.018 the first time I made this same beer, but with 1/4lb less lactose) so given those numbers and what I hit last time, I should have been down to around 1.020 FG (I believe). So I'm not as far off as I originally though, but still a little lower than what I was expecting.
I'll try raising the temp up a few degrees to try and kick start them and see if I can't get them to finish up a few more points.

Are you using a refractometer or hydrometer for your SG readings? A refractometer will not read accurately with alcohol present in the sample. Take a SG reading with a hydrometer, if you are not using one.

Hydrometer. I tested it in water as well, just to make sure it was accurate, and I was sitting right on 1.000.