OG Dead On, Missed FG

[Culln5]

I brewed an American Amber a couple weeks back and hit my Brewhouse Efficiency of 75% (75.1%) and my OG exactly at 1.050 but missed my FG horribly (1.022 of 1.013). I used fresh German Lager WLP830 packaged 12/26/14 and a 2L stater, then fermented at 50 degrees for 10 days and a 4 day d-rest. It is cold crashing now and will be kegged and lagered at 38 degrees for 30 days.

This should have been a nice easy drinking beer at 4.8%, but it's a bit light at 3.7%..... Any ideas why this happened?

 

[olotti]

Did u use a yeast calculator to determine the amount of yeast to pitch. Lagers need a ton of yeast since they ferment so cold my guess is you under pitched leading to a stalled fermentation. For instance I'm using a 2l starter of wlp001 for a 1.054 pale ale in making you prob needed a 3-4L starter. Just my guess I'm sue others will have more info.

 

[Culln5]

Did u use a yeast calculator to determine the amount of yeast to pitch. Lagers need a ton of yeast since they ferment so cold my guess is you under pitched leading to a stalled fermentation. For instance I'm using a 2l starter of wlp001 for a 1.054 pale ale in making you prob needed a 3-4L starter. Just my guess I'm sue others will have more info.

Yeah, I used BeerSmith's calculator. I was slightly under but I don't think I was critically under. I needed 367.3 billion and my starter yielded 355.3 billion.......

 

[olotti]

I use beersmith too but not the yeast calculator I find compared to Brewers friend and mrmalty it is always low maybe that was part of the problem. Seems somehow though u got a stalled fermentation although I've never used that yeast so I have no idea about is characteristics and attenuation.

 

[Culln5]

I use beersmith too but not the yeast calculator I find compared to Brewers friend and mrmalty it is always low maybe that was part of the problem. Seems somehow though u got a stalled fermentation although I've never used that yeast so I have no idea about is characteristics and attenuation.

I've really never had an issue with BeerSmith's starter calculations before.

 

[emyers]

What was your mash temp? You may have mashed too high. Did you aerate the cooled wort? Lager yeast needs more o2 than ale. Did u use any carapills or other dextrine malts?

 

[Culln5]

What was your mash temp? You may have mashed too high. Did you aerate the cooled wort? Lager yeast needs more o2 than ale. Did u use any carapills or other dextrine malts?

I mashed at 156 for an hour and batch sparged at 168 for 15 minutes. It's a new recipe. The base is 7 1/2 lbs Munich malt and 2 1/2 lbs of 2 row, no other malts. I have an inline O2 delivery system that aerates the wort as it goes into the fermentor.

 

[emyers]

Mashing at 152 would give you a dryer end fg. Are you sure your readings are corrected for 60f?

 

[Culln5]

Mashing at 152 would give you a dryer end fg. Are you sure your readings are corrected for 60f?

Yeah my hydrometer temp is usually below 70 degrees, so even with a .001 adjustment it is way low.

It has to be something with the yeast. My notes for the brew day don't indicate any outside influences or procedure problems. Maybe my primary (10 days) was too short? But then again, I only gained .002 during my 4 day d-rest.

Like I said, this is a new recipe and I haven't brewed with a Munich base before, so here's it is in case there is something hidden in it:


Recipe: ROAC
Style: American Amber Ale
TYPE: All Grain
Taste:

Recipe Specifications
--------------------------
Boil Size: 7.75 gal
Post Boil Volume: 6.50 gal
Batch Size (fermenter): 5.25 gal
Bottling Volume: 4.80 gal
Estimated OG: 1.050 SG
Estimated Color: 13.5 SRM
Estimated IBU: 20.8 IBUs
Brewhouse Efficiency: 75.00 %
Est Mash Efficiency: 89.3 %
Boil Time: 60 Minutes

Ingredients:
------------
Amt Name Type # %/IBU
1.00 tbsp PH 5.2 Stabilizer (Mash 60.0 mins) Water Agent 1 -
7 lbs 8.0 oz Munich Malt - 20L (20.0 SRM) Grain 2 75.0 %
2 lbs 8.0 oz Pale Malt (2 Row) US (2.0 SRM) Grain 3 25.0 %
1.00 oz Tettnang [3.90 %] - Boil 60.0 min Hop 4 12.9 IBUs
0.50 oz Spalter Select [4.75 %] - Boil 30.0 min Hop 5 6.0 IBUs
1.00 Items Wort Chiller (Boil 15.0 mins) Other 6 -
0.50 oz Saaz [3.20 %] - Boil 10.0 min Hop 7 1.9 IBUs
0.50 Items Whirlfloc Tablet (Boil 5.0 mins) Fining 8 -
1.0 pkg German Lager (White Labs #WLP830) [35.49 Yeast 9 -


Mash Schedule: McEllin - BIAB, Full Body, Batch Sparge
Total Grain Weight: 10 lbs
----------------------------
Name Description Step Temperat Step Time
Mash Step Add 20.00 qt of water at 163.5 F 156.0 F 60 min

Sparge: Batch sparge with 1 steps (3.95gal) of 168.1 F water
Notes:
------

Brew Process
- Heated 5.00 gallons of water to 163.5 and added the bag and grains
- Mashed for 1 hour (stirring every 15 minutes)
- Hung, drained, and moderately squeezed the bag
- Transferred the mash into the primary bucket
- Heated 4.00 gallons of water to 168 and added the bag grains
- Batch Sparged for 15 minutes (stirring often)
- Hung, drained, and moderately squeezed the bag
- Added the mash volume back to the kettle
- 60 Minute boil

Yeast
- 2l Starter

Fermentation
- 10 Day Primary @ 50 degrees
- 1.024 after Primary (3.4%)
- 4 Day D-rest @ 68 degrees
- Transferred to secondary on Day 5
- 7 Day Cold Crash @ 34 degrees
- 21 Day Lagering @ 34 degrees
- Kegged

Miscelaneous
- Brewhouse Efficiency to 75%
- Hit the Brewhouse Efficiency (75.1%) but missed the FG by .009 and the ABV by 1.1% (3.7%)

Created with BeerSmith 2 - http://www.beersmith.com
-------------------------------------------------------------------------------------

 

[Yooper]

It's the mash temperature. A high mash temperature creates more long-chained sugars, which are less fermentable. It makes a heavier bodied beer in the end, due to the unfermentable long-chain sugars.

I mash only my oatmeal stout now at 156- and it finishes at 1.022 or so. I used to mash my Dead Guy ale there as well, but sometimes it would end up too full bodied so I mash that at 154 now.

If your thermometer was even one or two degrees off, you could have been mashing at 158 and that would really create a wort with even more unfermentables, so make sure you calibrate your thermometer at mash temps to check that!

 

[DonnieZ]

It's the mash temperature. A high mash temperature creates more long-chained sugars, which are less fermentable. It makes a heavier bodied beer in the end, due to the unfermentable long-chain sugars.

I mash only my oatmeal stout now at 156- and it finishes at 1.022 or so. I used to mash my Dead Guy ale there as well, but sometimes it would end up too full bodied so I mash that at 154 now.

If your thermometer was even one or two degrees off, you could have been mashing at 158 and that would really create a wort with even more unfermentables, so make sure you calibrate your thermometer at mash temps to check that!

However, don't forget that lager yeasts can consume longer chain sugars than ale yeasts.

 

[Yooper]

However, don't forget that lager yeasts can consume longer chain sugars than ale yeasts.

Sure, but ale yeast will ferment maltriose also (not as to the same extent as lager yeast) and that is a very small portion of most wort anyway. Even lager yeast won't ferment the unfermentable dextrins.

 

[h22lude]

Mash temp definitely had something to do with it. Also, using Mr Malty, with that OG and production date it is saying you should have used two vials and a 4L starter. 1 vial in a 2L starter may not have been enough yeast. With a stir plate you could have gone with 2L but still needed 2 vials.

 

[Culln5]

I mash plenty of other recipes at 156 and have never had this issue before...... I can't help but think it is directly related to my yeast.

 

[h22lude]

Mashing high will definitely give you less fermentable sugars so your OG will be the same but your FG will be higher than expected. If you brought your mash down to 152, your FG would probably have been 3 or 4 points lower. So instead of 1.022 you would be 1.018. The other 5 points is most likely from not having a big enough starter.

Another possibility is equipment error. Did you calibrate everything? Maybe your thermo was off and you really mashed in at 158 which would give you an even higher FG than 156.

The 10 day primary may have had a thing to do with it as well.

I think there are a few things that could have caused this...high mash temp, equipment not calibrated correctly, taking out of primary too soon, not enough yeast. The only way to really now is to brew it again and check each of those things during that brew. I know this doesn't help you determine why but it gives you a few things to look at next time.

 

[Mirilis]

I'm nit-picky.. Your recipe says american amber ale but looks more like a Dunkel (without the dark malt)

 

[Culln5]

I'm going to finish the fermentation and hopeful enjoy it. I'll have a couple things to look out for next time it's brewed.

Thanks!

.... I can see the resemblance to a Munich Dunkel.

 

[craigmw]

What is in your water (e.g. Ca2+, Mg2+, TA levels), and what was your mash pH? pH can have a large impact on diastatic enzyme activity if it is outside of the optimal range (5.1-5.4).

 

[Culln5]

What is in your water (e.g. Ca2+, Mg2+, TA levels), and what was your mash pH? pH can have a large impact on diastatic enzyme activity if it is outside of the optimal range (5.1-5.4).

I'm not sure about the actual County water levels, but I do use PH 5.2 Stabilizer in the mash.

 

[craigmw]

I'm not sure about the actual County water levels, but I do use PH 5.2 Stabilizer in the mash.

You might check with your water district for levels of key ions like Ca2+, Mg2+, SO4-2, Cl-, carbonate and pH. The value of pH 5.2 buffer has been strongly questioned, so it could be worth your while to look at this more closely. If in doubt, brew with bottled water or better, RO water with added salts. Then plug in the values into Bru'n Water or Brewer's Friend's water chemistry calculator to bring your mash pH into the range of 5.1 to 5.4. See if this helps with your attenuation problem.

When I started, I also used the pH 5.2 buffer with little luck. It seemed I could never end below 1.020, even with recipes with few melanoidin high malts. I ended up downloading our local water district's numbers and have used them with Brewer's Friend. I also picked up a cheap pH pen. Our water is very hard so I end up having to add some phosphoric acid to adjust my mash pH and end up with reasonable results (based on testing the mash pH). I've also noticed much higher attenuation levels.