FG Finishing Lower than Intended

[LichtS]

Hey y'all.

I just dry hopped an IPA I brewed on Sunday. Down from 1.072 to 1.016 in 4 days. I pitched Conan Yeast at 66*F in my fermentation chamber.

My target FG was to be 1.019. While I don't mind a slightly higher in alcohol beer, I'd like to address the issue so I can have repetitive batches.

I mashed in at 153.5 according to my digital thermometer which was target. It dropped to 152.5 over the course of an hour. I did have a rather long sparge and my efficiency jumped up over 10% on this batch.

I haven't had an over attentuation like this before and I did not want a SUPER dry beer.

Suggestions? Cheers.

 

[kh54s10]

You cannot make the yeast read the predicted numbers. They will ferment the wort until they eat all the fermentable sugars. The predicted FG is just that.. A prediction.

IMO the difference between 1.019 and 1.016 is negligible. What was the predicted OG that had the predicted 1.019? Did you hit that OG? If your OG was 3 points low your 3 point low FG is perfect.

 

[Yooper]

Hey y'all.

I just dry hopped an IPA I brewed on Sunday. Down from 1.072 to 1.016 in 4 days. I pitched Conan Yeast at 66*F in my fermentation chamber.

My target FG was to be 1.019. While I don't mind a slightly higher in alcohol beer, I'd like to address the issue so I can have repetitive batches.

I mashed in at 153.5 according to my digital thermometer which was target. It dropped to 152.5 over the course of an hour. I did have a rather long sparge and my efficiency jumped up over 10% on this batch.

I haven't had an over attentuation like this before and I did not want a SUPER dry beer.

Suggestions? Cheers.

1.016 isn't a dry beer. It's about right, even on the high side, for an IPA. 1.019 as a target is pretty unreasonable, depending on yeast strain.

 

[doug293cz]

Setting aside the question of whether or not 1.019 is a reasonable FG target for an IPA, you didn't mention a mash out. Since you said "long sparge," I assume you are doing a fly sparge. During the time to do a long sparge, the fermentability of the wort will continue to increase if the amylase enzymes are still active. In order to prevent the fermentability from increasing during the sparge, you need to denature (deactivate) the enzymes. This is the purpose of a mash out, which is simply heating the mash to a temp of ~170°F, or a little higher. After about 10 minutes at this temp, the enzymes are denatured, and the fermentability of the wort stops increasing.

Brew on

 

[LichtS]

You cannot make the yeast read the predicted numbers. They will ferment the wort until they eat all the fermentable sugars. The predicted FG is just that.. A prediction.

IMO the difference between 1.019 and 1.016 is negligible. What was the predicted OG that had the predicted 1.019? Did you hit that OG? If your OG was 3 points low your 3 point low FG is perfect.

I agree that it's in the hands of the yeast. So a few things happened here. Estimated OG was actually 1.058 but my efficiency jumped higher on this batch and ended up at 1.068. I surpassed my original prediction.

 

[LichtS]

Setting aside the question of whether or not 1.019 is a reasonable FG target for an IPA, you didn't mention a mash out. Since you said "long sparge," I assume you are doing a fly sparge. During the time to do a long sparge, the fermentability of the wort will continue to increase if the amylase enzymes are still active. In order to prevent the fermentability from increasing during the sparge, you need to denature (deactivate) the enzymes. This is the purpose of a mash out, which is simply heating the mash to a temp of ~170°F, or a little higher. After about 10 minutes at this temp, the enzymes are denatured, and the fermentability of the wort stops increasing.

Brew on

I did perform a mash out and get the wort up to 168 degrees. Yes I fly sparged. While I don't see anything wrong with the numbers I've so far achieved I'm purely curious as to why. This is my first time pitching yeast of Conan variety and I've noticed that other members are seeing high attenuation.

Thanks for the reply Doug. Still chugging along here.

 

[LichtS]

1.016 isn't a dry beer. It's about right, even on the high side, for an IPA. 1.019 as a target is pretty unreasonable, depending on yeast strain.

Thanks for your reply. We'll see where she ends up, I will post my results. I feel like it will head down to 1.012-14.