Gravity reading off by 50 pts and I have no idea why!

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themanc84

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I brewed my third extract kit last week---Northern Brewer Imperial Stout. OG was supposed to be 1.086. I'm not sure if I'm missing something here, I usually take a gravity reading after the wort cools to 70 degrees (right before pouring into the fermenter)

When I took the gravity reading I got 1.038. I followed the recipe exactly as it was listed on the instructions. It was my third kit and I felt like this time around my system and procedures were perfect.

I was going to see what happens knowing that stouts can vary in strength but a friend of mine recommended that I add some boiled then cooled DME to the fermenter.

I did that last night now I'm hoping that the yeast wake up and some fermentation activity begins to present itself again. There wasn't much krausen at the top of the carboy compared to a few weeks ago when I brewed a bourbon porter kit.

Should I consider pitching more yeast? I intend on keeping the stout in the primary for another 2-3 weeks. Any help would be appreciated!
 
With extract beers the sugars can actually stratify where the heavier sugars sink and the watery solution get's pushed to the top. If you pulled your sample from the top portion of your fermenter then you probably just pulled a weak solution.

Either shake it up much better and resample, or just assume that since you followed the instructions to the 'T' that your OG is where it should be.
 
Yeah, it's actually not physically possible to miss your gravity by that much if you actually used all the extract the recipe called for. It's a mixture thing. It's too late, but adding more DME to the fermenter is likely to just add abv to your beer. I would've asked this question before messing with the beer in the fermenter, but since it's a RIS, you're likely just fine even with the added DME.
 
Extract kits usually hit the gravity numbers very closely. A low reading is almost always due to either not stirring the wort and thus getting an incorrect reading or because part of the fermentables did not get added. Adding more DME to an extract kit without first finding the problem can create additional issues.

So,

(1) Did you double check that the kit had all of the fermentables listed on the instruction sheet?
(2) Did you double check that all of the fermentables got added to the boil / fermentor?
(3) Did you stir the full volume of the wort thoroughly before taking your gravity reading?

If you did all of these things correctly, then

(4) Double check your hydrometer in 60 degree (or 68 degree) water to make sure it reads properly.

If all of these things are good, then chalk it up to a learning experience and see how the beer turns out!
Good Luck,
Cody
 
Thank you for your responses! I probably should have posted on here before taking my friend's advice.

I did take a sample from the top of the wort which is probably what caused the low gravity reading.

I suspected that the gravity was low anyhow because fermentation activity was only visible for a few days and nothing came through the blowoff tube as I expected. When I brewed my Bourbon Porter kit a few weeks ago it looked like I lost almost a quart of beer through the blowoff tube so I was expecting the same this time around (there is also a lot less krausen on the top)

I only added about a half pound of Extra Pale DME. The yeast look like they are waking up a little. There is activity in the airlock every 45 seconds. Prior to adding the DME it seemed that the air bubbles had stopped completely.
 
Thank you for your responses! I probably should have posted on here before taking my friend's advice.

I did take a sample from the top of the wort which is probably what caused the low gravity reading.

I suspected that the gravity was low anyhow because fermentation activity was only visible for a few days and nothing came through the blowoff tube as I expected. When I brewed my Bourbon Porter kit a few weeks ago it looked like I lost almost a quart of beer through the blowoff tube so I was expecting the same this time around (there is also a lot less krausen on the top)

I only added about a half pound of Extra Pale DME. The yeast look like they are waking up a little. There is activity in the airlock every 45 seconds. Prior to adding the DME it seemed that the air bubbles had stopped completely.
1/2 pound won't kill you. Airlock activity or inactivity is not a sure sign of fermentation. Let it be, let it do its thing for a good 7-10 days, take a sample and see where you're at. Don't listen to your friend.
 
With extract beers the sugars can actually stratify where the heavier sugars sink and the watery solution get's pushed to the top. If you pulled your sample from the top portion of your fermenter then you probably just pulled a weak solution.

Either shake it up much better and resample, or just assume that since you followed the instructions to the 'T' that your OG is where it should be.

^ This.
 
Thank you for your responses! I probably should have posted on here before taking my friend's advice.

I did take a sample from the top of the wort which is probably what caused the low gravity reading.

I suspected that the gravity was low anyhow because fermentation activity was only visible for a few days and nothing came through the blowoff tube as I expected. When I brewed my Bourbon Porter kit a few weeks ago it looked like I lost almost a quart of beer through the blowoff tube so I was expecting the same this time around (there is also a lot less krausen on the top)

I only added about a half pound of Extra Pale DME. The yeast look like they are waking up a little. There is activity in the airlock every 45 seconds. Prior to adding the DME it seemed that the air bubbles had stopped completely.

-so how long after putting the wort into your ferment bucket did you get the 1.038 reading? If it was a few days it might have been correct...
-if you added .5# of DME it should boost gravity by about .004.. I think... :rockin:
 
I took the gravity reading right after the wort cooled to 70 degrees, before putting it in the fermenter.
 
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