Different OG readings??

[shorestyle]

So I brewed an IPA last night and took a gravity reading after aerating and before pitching my yeast. My target gravity for the batch is 1.068. The first reading gave me 1.080 with the wort at 68 degrees.

So I pitched my yeast and let it settle for about 20 mins, took another reading and got 1.070 at roughly the same temp.

I took another reading today. Fermentation has started and have a nice healthy krausen. The beer is sitting at 64 degrees. The reading I got today is 1.068.

So after this I am concluding my second OG reading was the correct one but is there any reason why the first one was .010 higher? I can't figure out why and have asked a pro brew master I know and he doesn't have an answer for me either.

Any light on the subject would be super helpful. Thanks!

 

[Brew_G]

Was it an extract or all-grain brew?

 

[shorestyle]

Was it an extract or all-grain brew?

Extract

 

[brew_ny]

Extract

if you put in all the extract needed to get you OG then it is all good

it is hard to get a good mix with extract

all the best

S_M

 

[BlueHouseBrewhaus]

If it was a partial boil (i.e. you used top up water) it may not have fully mixed before your first reading. You don't say how you aerated but if you used the tried and true "shake the crap out of it" method, another possibility is there might have been a lot of bubbles rising in your OG sample that slightly "floated" your hydrometer. Either way, I think you are right to trust your second reading.

 

[shorestyle]

Yeah I aerated it by shaking the crap out of it. Bubbles definitely sounds like the most plausible reason for the reading being off.

My pre-boil volume was 18 L in a 19 L pot. I'd say I topped up with about 3 L or so

 

[Brew_G]

Extract

This is the first thing I'd suspect as the culprit. Getting a consistent OG reading on an extract brew is tough because the sugars aren't always evenly distributed throughout the wort, even if the wort has been agitated.

I wouldn't worry about it. As mentioned above by brew_ny, as long as you added the correct amount of extract needed to get your OG, then you're good.