Gravity readings

[Brewno]

Hi,

The extract recipe I made last week said it would be 1.050 OG ( (FG 1.013) I did an online calc of the ingredients and it came out the same. However my OG came out to be 1.042.

Here are the changes I made to the recipe but can't figure out why that would have any influence. That may well be my lack of knowledge. First off the recipe called for 1.5 gals of water. I've made a couple this way and found it too concentrated (thick ) after evaporation and boiling so I upped it to 2.5 gal in the brew pot. The other change I made was to do an extract late. My late addition was done at 15 minutes left in the boil and I used half of my total extract. (the total was 6.6 lbs). Other than that I followed the recipe.
Now I thought that the addition of more water would lower the gravity but then thought "what's the difference?" If I didn't do it in the kettle I would do it in the fermenter anyway to bring it up to 5 gal. Then I thought about the late addition.
But that would make the gravity lower only "during" the boil before I added the last extract wouldn't it? Not after adding more extract.
Any clues? Also what should my new FG be? I fear I may end up with a 2% ABV beer


Thanks

 

[Orfy]

If you eventually topped up to the same volume using the same over all amount and used the same over all amount of extract then given no other significant variable you wort will end up at the same gravity.

The main error occurs in not stirring and mixing the extract and water sufficiently to mix. Thus causing an false hydrometer reading. Always lower than it should be due to the higher gravity extract falling to the bottom of the fermenter.

 

[EdWort]

Adding water will reduce your O.G. Your F.G. depends on the attenuation of your yeast. Chances are, you will be pretty close to it. If you hit your target F.G. of 1.012 you will have a 4% beer.

 

[Brewno]

The wort/water was stirred well, I usually shake up the carboy before pitching to aerate and then again after. I took the reading before pitching obviously.

 

[Orfy]

If you use the same over all water volume.
And
The same over all amount of wort (same gravity)

The OG will be the same.

If you increased the water or decreased the malt then the OG will go down.


I can't tell from your post if you reduced the extract by half or just did two additions.
I reads like you did reduce the extract. That will reduce the OG.

 

[Brewno]

I can't tell from your post if you reduced the extract by half or just did two additions.
I reads like you did reduce the extract. That will reduce the OG.

Sorry, 2 additions. One at the start of the boil (3.3 lbs) and the second 3.3 lbs at 45 minutes into the boil.

 

[Orfy]

So apart from minimal gravity loss at the boil

You have

the same volume of water
the same volume of extract

Therefore your OG will be the same.
Therefore your gravity reading was wrong. Or some other error was made.

This happens often with extract brewers not doing full boils

You will get minor variations but nothing large.

 

[Brewno]

Thanks,

So I should look for the same FG (1.013) to determine when to rack? I was thinking a few points lower because of my OG reading but I guess that is incorrect.

 

[Orfy]

Multiple variables ditermine the FG
The 1013 is a guide line and target rather than an actual.

But yes I'd say go for around that.

 

[Brewno]

Thanks again