Please help explain low final gravity on Bohemian Pilsner

[MrDarcy]

Hey all,

Just recently, with temps at a stable mid-upper 50s in my garage, I thought I'd try my first lager using Fermentis S-23 (seems to tolerate slightly elevated lager fermentation temps). Anyhow, I followed the Brewing Classic Styles recipe for Bohemian Pilsner and hit my targeted OG, etc. I pitched 2 packages of S-23 and fermented at 59F solid. But I took a sample today (about a week into fermentation) thinking I'd gauge whether to start a diacetyl rest, and it had already fermented out (I'm presuming) to 1.010! My targeted FG was 1.015.

Is the S-23 to blame?

In appearance, it also looked very pale straw in color, paler than a German lager or a Kolsch. And taste-wise, I certainly didn't get much malt character at all, maybe a slight graininess. I could taste those Saaz hops, though.

I guess I'm just looking for any insight into my process or recipe that could account for this disappointing result. And, I know it's only been fermenting a week, but can I expect any improvement in color or malt complexity over time?

A couple notes:

I was targeting a mash temp of 154F, but I was at 153.5F on the high end and probably 151F at the end of the mash.

I've been suspecting recently that maybe my mash pHs have been high. I ordered a pH meter but didn't have it for this brew. An online calculator suggested (given my grist and water profile) a pH of 5.8.

Anyhow, here's the recipe and thanks so much for any insight or suggestions!

Style: Bohemian Pilsner
TYPE: All Grain

Recipe Specifications
--------------------------
Boil Size: 6.77 gal
Post Boil Volume: 5.72 gal
Batch Size (fermenter): 5.50 gal
Bottling Volume: 5.50 gal
Estimated OG: 1.056 SG
Estimated Color: 3.4 SRM
Estimated IBU: 40.2 IBUs
Brewhouse Efficiency: 72.00 %
Est Mash Efficiency: 72.0 %
Boil Time: 90 Minutes

Ingredients:
------------
Amt Name
10 lbs 12.0 oz Weyermann floor-malted Bohemian Pilsner malt (1.6 SRM)
12.0 oz Carapils (Briess) (1.5 SRM)
1.38 oz Saaz [3.50 %] - Boil 60.0 min
1.67 oz Saaz [3.50 %] - Boil 30.0 min
0.83 oz Saaz [3.50 %] - Boil 10.0 min
0.83 oz Saaz [3.50 %] - Steep/Whirlpool 15.0 mi
2.0 pkg SafLager West European Lager (DCL/Fermen Yeast 7 -

Mash Schedule: Single Infusion, Light Body, Batch Sparge
Total Grain Weight: 11 lbs 8.0 oz
----------------------------

Mash In Add 16.38 qt of water at 168.8 F

154.0 F 75 min

Sparge: Batch sparge with 2 steps (Drain mash tun , 4.56gal) of 170.0 F water

 

[kh54s10]

The slightly low mash temperature may have helped the final gravity go lower but note that predicted gravity is just that, a prediction. I never worry too much what the final gravity ends up being. If it is lower the ABV might be a touch higher and the beer might be a bit drier. But they are always good.

With that grain bill I am not surprised at all that it is very pale in color. You would need to add a grain with a larger SRM to get a darker beer.

I wouldn't make too much of a judgement on the taste. It is likely to be a lot different when bottle conditioned or kegged.

I have been brewing all grain (only 2 lagers so far) for 3 years. I have yet to do any measurement of pH.

I am only now thinking of getting my water analysed. Hopefully to make my very good beers even better. So far just charcoal filtered tap water.

 

[BrewerBrad82]

I would say that all is well. If you look at the data sheet for this yeast, it lists its attenuation at 82%, which is exactly what you got. Nothing better than a nice dry BoPils!

http://www.fermentis.com/wp-content/uploads/2012/02/SFG_S23.pdf