Low OG

[AustinBrewDawg]

Hi all, first post here (yay me). So Saturday I went to my local homebrew store (Austin Homebrew) and got my first homebrew kit and an Extract recipe kit to make a locally popular blonde ale (Real Ale Fireman's #4). I followed the instructions to the letter and so far am pleased that what I am seeing is matching what I was told to expect. EXCEPT, after pitching the yeast and prior to lidding the primary, I took a hydrometer reading and only yielded an OG of 1.018. The recipe page said that I should expect an OG of 1.050. So, should I be concerned? How much variation should one expect? The only thing I can figure is that I filled it with too much water (5 1/4 gallons, per the recipe). Will this have any impact on the flavor or alcohol content. FYI, the airlock started churning nicely after about 12 hours.

Anyway, thanks and I look forward to contributing here in the future.

 

[BendBrewer]

Probably an issue of you topped off with water and didn't mix it. When using extract, as long as you measure stuff reasonably close it's real hard to miss your target.

I bet you are fine. Assume you hit 1.050ish.

 

[TTB-J]

No worries - it's quite common to get screwy gravity readings when you're using top off water to get to your final batch size. What likely happened was that you drew a sample that had more top off water than wort, which resulted in the low OG reading. You really have to do a fantastic job of shaking and mixing the two before you can get reliable gravity readings, and even then you still may get some error. The convection process of fermentation will properly mix everything together and I bet it will turn out just fine. Congrats on your first brew!

 

[Kaz]

If you did a partial boil, added all the extract and sugars included in the kit, and then added top off water, then the top off water probably wasn't totally mixed giving you a skewed hydrometer reading. You could get a lower reading if you added too much water, but to get from 1.050 to 1.018, you would have had to add over 7 gallon extra of water...I doubt that happened. Are you sure you were looking at the right numbers on your hydro...I've made that mistake before. Otherwise, take a reading in a week after the yeast has churned everything together and I bet it will be better.

 

[AustinBrewDawg]

Thanks guys. You're probably right about inadequate mixing. I did add 2 1/4 gallons of water to the wort in the primary. A good lesson for next time.

 

[BendBrewer]

Thanks guys. You're probably right about inadequate mixing. I did add 2 1/4 gallons of water to the wort in the primary. A good lesson for next time.

It's a good idea to aerate your wort prior to pitching the yeast. Most new folks add the top off water, put the lid on and then shake the crap out of the bucket for a few minutes. You could do that and then take your reading although it will be a little skewed unless you knock the air out of the sample that you just shook into it but it will be real close.

You could also take a reading before you top it off and do some math to get your actual OG. But again, efficiency isn't that big of a deal with extract brews as your factors are known and already done. How much sugar and how much water. PM and AG brewers concern themselves with it as they are actually performing the step that determines how much sugars they end up with. In extract, it's really just a matter of measuring the extract and water volumes correctly.

 

[ThePearsonFam]

It's a good idea to aerate your wort prior to pitching the yeast. Most new folks add the top off water, put the lid on and then shake the crap out of the bucket for a few minutes. You could do that and then take your reading although it will be a little skewed unless you knock the air out of the sample that you just shook into it but it will be real close.

You could also take a reading before you top it off and do some math to get your actual OG. But again, efficiency isn't that big of a deal with extract brews as your factors are known and already done. How much sugar and how much water. PM and AG brewers concern themselves with it as they are actually performing the step that determines how much sugars they end up with. In extract, it's really just a matter of measuring the extract and water volumes correctly.

+1 Was going to mention that aeration will ensure good mixing.

 

[AustinBrewDawg]

Took an SG last night (4 days post-pitch) and came up with 1.012. The predicted FG is 1.015. So I took it three more times and came up with 1.012. I was inserting the hydrometer in my thief, and doing the Mr. Miyagi hand roll to make sure the hydrometer wasn't getting hung up on the side of the thief. The sample was taken from the middle of the bucket height (so as not to get any trub or krausen). I thought it might be reading low. So I cleaned the thief and hydrometer and tested a sample of spring water from a bottle. The reading came out at 0.995. At this point, I'm skeptical that spring water full of minerals is lighter than water, so I think my hydrometer may be a little "heavy". I'm thinking about taking it to Austin Homebrew and get them to test it. Anyone else have this problem?

 

[ThePearsonFam]

If your hydrometer has the paper in the middle (almost all do), then there's a chance that the paper has slid down (which would also explain your low OG). Get some distilled water, make it 60F and see if your hydrometer reads 1.000.