Partial Boil - Wort Mixing & O.G. Question

[tado]

Not sure if this is already a thread or not (couldn't find one), but I recently did a partial boil and forgot to vigorously mix the wort & the 3 gallons already in the primary before pitching the yeast. I've seen on some threads that people highly recommend mixing the two together very well before pitching the yeast. What effect will this have on the brew?

Also, I took my O.G. reading before I topped off the primary, which probably explains why it was so high. Is there a way to figure out the ABV when I take the S.G. reading when racking to the secondary? I plugged in all my ingredients into BeerTools Pro and it says the final ABV should be around 5.5%, so I'm not too worried but I'd like to try to figure it out on my own Here is the recipe that I'm working with.

7.5 lb Amber Malt extract syrup
8 oz. Roasted barley
4 oz. Black patent malt
1 oz. Chocolate barley
1 1/2 oz. Northern Brewer
1/4 oz. Cascade

 

[Suthrncomfrt1884]

Since you're using extract, the chances are pretty good that you'll hit your ABV mark. The grains you used won't convert much since you didn't use a base malt in your mash, so I wouldn't count on those to add much.

As for gravity readings...it's really too late at this point. Just check it to make sure it's finished. Don't worry about not mixing. It will all eventually blend together in the fermentor.

 

[Palefire]

You could actually probably calculate your proper OG if you took an OG reading before topping off. I might be wrong here, but it seems like it'd be a pretty simple ratio: Measured OG / Volume of un-topped-off wort = True OG / Total Volume (wort+water)

Plug in everything and solve for "True OG." But, as the previous poster said, it's pretty difficult to miss an OG when almost all of your sugar is coming from extract. So you're probably pretty right on anyway.

And don't worry about not mixing as far as fermentation goes. The fermentation process will mix it up fine.

 

[tado]

You could actually probably calculate your proper OG if you took an OG reading before topping off. I might be wrong here, but it seems like it'd be a pretty simple ratio: Measured OG / Volume of un-topped-off wort = True OG / Total Volume (wort+water)

Interesting idea, but I don't think that works. I tried it and the True OG (according to that formula) would be 2.8775 and I'm hoping it won't be that low Thanks for the replies & reassurance though!

 

[Palefire]

right ... sorry, was hurrying when I wrote that. So you have to drop the 1 for the gravity readings here (so 1.036 becomes 36), and switch the places of the volumes in that little ratio. So basically take your measured OG (without the 1) and multiply it by (volume of un-topped-off wort / Total volume).

Does that get you close? Maybe someone else will weigh in here, so I might be wrong, but it seems like it should be right.