First All Grain... Gravity Question

[ted464]

I recently brewed my first all grain batch which is a porter. The grain bill was 9 lbs of Maris otter with 2 lbs of specialty grains. My mash stabilized at about 154, which I mashed for 75 minutes (iodine test) in a converted 10 gallon igloo. I batch sparged in two stages with 168 water. After a one hour boil I ended with five gallons with an OG of 1.049 (when adjusted for temp). I pitched a 1.5L starter of WLP004 (Irish Ale), which I have never used before. After 24 hours the gravity dropped to 1.022. It is now five days into primary (6.5 gallon plastic bucket) and the gravity is sitting at 1.021 and hasn't dropped in three days. Is this normal for this yeast? Do I need to pitch another vial? Should I wait it out another week? Is this a stuck fermentation? As this is my first all grain batch I am very excited and nervous at the same time. I bottle with table sugar (just FYI), and want to know when it would be safe to do so. Any help would be appreciated, thanks.

 

[Yooper]

I recently brewed my first all grain batch which is a porter. The grain bill was 9 lbs of Maris otter with 2 lbs of specialty grains. My mash stabilized at about 154, which I mashed for 75 minutes (iodine test) in a converted 10 gallon igloo. I batch sparged in two stages with 168 water. After a one hour boil I ended with five gallons with an OG of 1.049 (when adjusted for temp). I pitched a 1.5L starter of WLP004 (Irish Ale), which I have never used before. After 24 hours the gravity dropped to 1.022. It is now five days into primary (6.5 gallon plastic bucket) and the gravity is sitting at 1.021 and hasn't dropped in three days. Is this normal for this yeast? Do I need to pitch another vial? Should I wait it out another week? Is this a stuck fermentation? As this is my first all grain batch I am very excited and nervous at the same time. I bottle with table sugar (just FYI), and want to know when it would be safe to do so. Any help would be appreciated, thanks.

It's not normal for that yeast, no. Are you sure that your mash never got above 154? It sounds more like you mashed at 160/162 or so to get a high FG like that. Also, I assume that the specialty grains you used (a lot of them) were less fermentable types.

You could wait it out, and bottle it once it's clearing and the FG doesn't change.

 

[ted464]

It's not normal for that yeast, no. Are you sure that your mash never got above 154? It sounds more like you mashed at 160/162 or so to get a high FG like that. Also, I assume that the specialty grains you used (a lot of them) were less fermentable types. You could wait it out, and bottle it once it's clearing and the FG doesn't change.

Ok thanks. I don't think it got that high, but I'm not 100% sure. I did stir twice during the mash to try and prevent hot spots, but who knows. The specialty malts were a pound of victory and a pound of chocolate if that helps, the good news is it tastes good so far.

 

[duboman]

Also, are you reading with a hydrometer or refractometer? If the latter, use the former as once alcohol is present a refractometer is not the best even with calculated adjustments

Also, Your adjusted OG, what temp did you correct it from? Anything higher than 90-100 F is pretty worthless so your OG may have been higher than you read but even so you should be lower than 1.021. A pound of chocolate malt is a lot and will effect the FG, especially if you mashed higher than you think you did.

What temp are you fermenting at? you can try to raise the temp and rouse the yeast and see if it will restart and finish.

 

[W0rthog]

I'm curious what method you used to aerate the wort?

 

[ted464]

I aerated by just pitching back and forth a few times to a sanitized bucket. I am fermenting at 68 degrees. The OG was taken at 85 degrees and the OG was per beersmith for that temp.

 

[ted464]

I aerated by just pitching back and forth a few times to a sanitized bucket. I am fermenting at 68 degrees. The OG was taken at 85 degrees and the OG was per beersmith for that temp.

. Oh and hydrometer.

 

[atom]

wait another two weeks and bottle. 1.021 isn't too high for a porter...

 

[stpug]

Long shot here:
Is the sample you pull from your fermenter slightly carbonated? If it is, I'm wondering if the carbonation is "lifting" the hydrometer up a little bit giving a higher reading than actual. You can try spinning the hydrometer when to get any carbonation bubbles to release which should allow it to settle down for a few seconds.

Is this a 5 gallon batch? And, did you pour in all of the 1.5L of starter, or did you crash and decant first? I'm just wondering about your OG (off the top of my head it seems little low but not terribly).

 

[ted464]

Ok, going to play the waiting game at this point. Thanks for all the help guys.

 

[MindenMan]

I agree with stpug, when I draw samples out of primary there is always a slight carbonation that could ruin my hydro reading. I tap on the side with the tube the hydro is stored in, and/or I wait 30 minutes or so and check if there are still bubbles.