Final gravity 1.002... not supposed to be that low

I brewed the a belgian strong golden ale. Here's the recipe

It uses WLP570 yeast which has an attenuation of 73-78%. According to the attenuation I got on Brewer's Friend is 92.3%. When brewing I got a 1.078 OG. When i checked it yesterday it was at 1.002. It was supposed to finish out at 1.019 according to the recipe. I made a 1 liter yeast starter.

I did notice the bubbling in the airlock took about a day to start which usually starts about 12 hours. I assume I've got some type of wild yeast or other bug. I just cold crashed it yesterday and up until a few days ago, it was still bubbling... it had been bubbling for about 5 weeks.

The thing is, it smells and tastes like it supposed to. What do you think?

same thing happened with my imperial pumpkin. 1.125 to 1.004, 96% attenuation and 15.8% ABV

not to be used for beer pong

two things I can think of that might have caused my over-attenuation.

#1 - it was cold the day I brewed and my mash temps dropped about 6-7 degrees over the hour-long mash

#2 - the recipe called for the addition of fermentables during primary, the last being a pound of sugar. recipe called for beet, I used cane, not sure if that makes any difference. SG before that last addition was 1.018, which was where I expected it to finish up

so maybe I call it a pumpkin barleywine instead of an imperial pumpkin ale

another thing that might have affected yours is ferment temp. mine I was able to keep in the low to mid 60s for entire primary. so I don't think that had any influence on mine.

When you figure out what happened let me know because I have a pale ale that started at 1.049 and was supposed to finish at 1.016. The last sample showed it at 1.002. I see and taste no signs of infection either and the sample tasted really good. I've had other batches that finished lower than predicted but this is exceptional.

jasonclick said:

I brewed the a belgian strong golden ale. Here's the recipe

It uses WLP570 yeast which has an attenuation of 73-78%. According to the attenuation I got on Brewer's Friend is 92.3%. When brewing I got a 1.078 OG. When i checked it yesterday it was at 1.002. It was supposed to finish out at 1.019 according to the recipe. I made a 1 liter yeast starter.

I did notice the bubbling in the airlock took about a day to start which usually starts about 12 hours. I assume I've got some type of wild yeast or other bug. I just cold crashed it yesterday and up until a few days ago, it was still bubbling... it had been bubbling for about 5 weeks.

The thing is, it smells and tastes like it supposed to. What do you think?

Click to expand...

If you mashed a little cool then will get you a highly fermentable wort. Add that to WLP570 which can attenuate like a fiend and you will get some very low FGs. 1.078 to 1.002 is pretty amazing, but definitely possible especially with a warm ferment. Doesn't sound like a wild yeast to me.

I am having the same issue with over attenuation. My yeast has been giving me an average of 85%. My last batch mashed at 155 and started at 1.066 and was supposed to finish around 1.016. Pitched one packet of US-05 straight into the wort and fermented at an ambient 65 degrees. Dry hopped last night and I am already at 1.010. Can't figure it out.

BigDaddyBeard said:

I am having the same issue with over attenuation. My yeast has been giving me an average of 85%. My last batch mashed at 155 and started at 1.066 and was supposed to finish around 1.016. Pitched one packet of US-05 straight into the wort and fermented at an ambient 65 degrees. Dry hopped last night and I am already at 1.010. Can't figure it out.

Click to expand...

Are you sure your thermometer is accurate?

Yup, checked with two separate thermometers and that is what my thermostat is set on.

https://www.homebrewtalk.com/f36/controlling-attenuation-through-mash-times-60576/

This thread has some great info about attenuation. It mainly discusses getting better attenuation through longer mash times, but I would assume the opposite would also be true.

That's pretty low, but your recipe is tailored for a low FG. Depending upon the health and amount of yeast pitched, and the fermentation schedule, this doesn't seem too far out of the ordinary.

opiate82 said:

https://www.homebrewtalk.com/f36/controlling-attenuation-through-mash-times-60576/ This thread has some great info about attenuation. It mainly discusses getting better attenuation through longer mash times, but I would assume the opposite would also be true.

Click to expand...

Thanks that's great info! I may try dropping my mash from 60 to 40 minutes and see if it helps

Before you start majorly adjusting mash times, I would double check all of your equipment first.

You said your thermometers gave you the same readings but did you ensure that they accurate by testing them in an icewater bath and/or boiling water?

How are you taking your gravity readings? If using a hydrometer have you checked to make sure it measures 1.000 in distilled water? I check mine every so often because the little paper inside the hydrometer can easily shift in there.

I would double check all of your measuring equipment first to ensure you are getting accurate readings, then if everything is reading accurately, I would adjust you mash time in smaller increments till you get it dialed in (maybe down to 50min to start).

BigDaddyBeard said:

Thanks that's great info! I may try dropping my mash from 60 to 40 minutes and see if it helps

Click to expand...

Good luck with the decreased mash times. I already mash for only 30 minutes.

opiate82 said:

Before you start majorly adjusting mash times, I would double check all of your equipment first. You said your thermometers gave you the same readings but did you ensure that they accurate by testing them in an icewater bath and/or boiling water? How are you taking your gravity readings? If using a hydrometer have you checked to make sure it measures 1.000 in distilled water? I check mine every so often because the little paper inside the hydrometer can easily shift in there. I would double check all of your measuring equipment first to ensure you are getting accurate readings, then if everything is reading accurately, I would adjust you mash time in smaller increments till you get it dialed in (maybe down to 50min to start).

Click to expand...

I checked my equipment every month or two and have duplicates.

jasonclick said:

I brewed the a belgian strong golden ale. Here's the recipe

It uses WLP570 yeast which has an attenuation of 73-78%. According to the attenuation I got on Brewer's Friend is 92.3%. When brewing I got a 1.078 OG. When i checked it yesterday it was at 1.002. It was supposed to finish out at 1.019 according to the recipe. I made a 1 liter yeast starter.

I did notice the bubbling in the airlock took about a day to start which usually starts about 12 hours. I assume I've got some type of wild yeast or other bug. I just cold crashed it yesterday and up until a few days ago, it was still bubbling... it had been bubbling for about 5 weeks.

The thing is, it smells and tastes like it supposed to. What do you think?

Click to expand...

That attenuation seems about right given your recipe and yeast selection. The recipe has 3 lbs of sugar, no specialty grains, and you mashed at 149F. All of those things lead to very high attenuation. Plus it's a Belgian yeast which are generally pretty highly attenuating.

And 1.019 would be way too high an FG for that style anyway. Sounds like you brewed a great beer.

opiate82 said:

How are you taking your gravity readings? If using a hydrometer have you checked to make sure it measures 1.000 in distilled water? I check mine every so often because the little paper inside the hydrometer can easily shift in there.

Click to expand...

definitely check that paper scale. mine shifted to read .014 points low

caused me to add DME to a batch that didn't need it

BigDaddyBeard said:

Thanks that's great info! I may try dropping my mash from 60 to 40 minutes and see if it helps

Click to expand...

If you're trying to decrease attenuation, you're better off mashing hotter and shorter rather than just shorter. The highly modified malts we generally work with convert wicked quickly, but the higher temps will produce lots of long-chain dextrines that are unfermentable.