Hot Mash, Low Attenuation

[Cajun_McChicken]

Hi All,

I was trying to brew a nice malty IPA but my mash temp was a bit high (157F). Based on this, BeerSmith says my expected final gravity is 1.018. I pitched a healthy 1L starter of White Labe 007 Dry English Ale yeast and after two weeks in the fermenter it has gotten down to 1.020 but the testing samples still have a bit of a cloying sweetness.

Do you think it is possible to push the final gravity a bit lower by re-pitching a packet of S-05 or some other yeast or am I boned by the too-high mash temp?

Thanks!


BeerSmith 2 Recipe Printout - http://www.beersmith.com
Recipe: Newport/Cascade IPA
Brewer:
Asst Brewer:
Style: American IPA
TYPE: All Grain
Taste: (30.0)

Recipe Specifications
--------------------------
Boil Size: 7.48 gal
Post Boil Volume: 5.98 gal
Batch Size (fermenter): 5.50 gal
Bottling Volume: 5.40 gal
Estimated OG: 1.065 SG
Estimated Color: 10.0 SRM
Estimated IBU: 68.1 IBUs
Brewhouse Efficiency: 80.00 %
Est Mash Efficiency: 83.6 %
Boil Time: 90 Minutes

Ingredients:
------------
Amt Name Type # %/IBU
8 lbs Pale Malt (2 Row) US (2.0 SRM) Grain 1 65.3 %
2 lbs White Wheat Malt (2.4 SRM) Grain 2 16.3 %
1 lbs Caramel/Crystal Malt - 60L (60.0 SRM) Grain 3 8.2 %
1 lbs Munich Malt - 10L (10.0 SRM) Grain 4 8.2 %
4.0 oz Acid Malt (3.0 SRM) Grain 5 2.0 %
1.00 oz Newport [12.50 %] - First Wort 90.0 min Hop 6 48.5 IBUs
1.00 oz Cascade [8.30 %] - Boil 20.0 min Hop 7 15.1 IBUs
0.50 oz Cascade [8.30 %] - Boil 10.0 min Hop 8 4.5 IBUs
1.50 oz Cascade [8.30 %] - Boil 0.0 min Hop 9 0.0 IBUs
1.0 pkg Dry English Ale (White Labs #WLP007) [35 Yeast 10 -
2.00 oz Cascade [8.30 %] - Dry Hop 14.0 Days Hop 11 0.0 IBUs


Mash Schedule: Single Infusion, Full Body, No Mash Out
Total Grain Weight: 12 lbs 4.0 oz
----------------------------
Name Description Step Temperat Step Time
Mash In Add 15.31 qt of water at 174.2 F 157.0 F 45 min

Sparge: Fly sparge with 5.12 gal water at 168.0 F
Notes:
------


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

Have you tried rousing the yeast? One reason that English yeasts sometimes finish with low attenuation is because many of them flocculate a lot. Get them back into suspension and they may hit another few points. Also consider raising the temperature.

If that doesn't work, pitching new yeast, along with nutrient, could help. You're in a somewhat tough spot, since 1.020 is high but not that far from what you want (I assume, given the high mash temperature). Pitching a more aggressive yeast, like 3711, could definitely attenuate it further, but that might overshoot. US-05 might overshoot too, but it's hard to predict how the second yeast will behave. I guess if it were me, I'd pitch the US-05.

There are other solutions too, including adding additional hop bitterness (by using a hop tea or similar at bottling time) or blending the beer with a drier one.

 

[duboman]

+1,
Those are about the only options you have. To add: Be sure your thermometer is calibrated as you might have actually mashed higher than you think

 

[tomhen]

The problem as you have already figured out is you produced too many dextrins in your wort so extra yeast isn't going to do it. Age it and brew another with a mash of 147 then after it ferments blend the two and you should have a great beer!

 

[Cajun_McChicken]

Thanks for all the advice! I'll try rousing and cranking up the temp in my ferm chamber first.