Significantly Missed OG with Extract

[Jimbutler21]

Has anyone ever experienced significant miss with their OG while doing extract? I'm talking hitting 1.020 when trying to hit 1.040. I brewed a batch of Northern Brewer Cream Ale this afternoon and am beyond pissed it missed the mark so badly. I'm not a new brewer and have made plenty of extract beers (and PM and AG on top of that) and never had such a miss with OG.

I did a couple things different today than usual, but wouldn't expect such a drastic change. I brewed on stovetop instead of on propane burner (because it's f-ing hot in TX and I was working-from-home), which led to a much slower boil. It took FOREVER to even reach boil. Starting volume was 3.5 gallons, post-boil volume was ~3.25 gallons, which I then topped off to 5. (I know, I should have taken hydrometer reading prior to topping off, but can't go back in time.) I even used used hot water to rinse all of the LME out of the container and into my boil kettle, so I'm sure I got all the sugars in the wort. I've read the OG on 3 different devices and got comparable results, so I don't think it's an issue with my instruments.

Traditional Hydrometer: 1.018
Refractometer: 1.024
Tilt Hydrometer: 1.022

I read one article that said sugars can sink to the bottom and impact the OG reading. Is it possible to be off by that much? I've shaken the bejesus out of the fermenter and had little impact on the OG. I've run the numbers through several calculators and it's as though I used half the LME I should have, even though I'm sure I used all 6 lbs. (+1 lbs. of specialty grains, although I haven't included them in calculations since they shouldn't impact OG significantly).

Any thoughts on what would cause the OG to be so far off? And other question, what to do now? I ran the numbers and it looks like if I add another 4 lbs. LME in 1 GAL of concentrated wort that should correct the issue, right? Any help is much appreciated. Thanks!

 

[Abhishek Dewan]

Looks like a case of bad batch. Nothing wrong about process you described. Add more malt extract as you’ve mentioned. No need to boil again. Lot of people bump up gravity in phases by adding sugars later.

 

[RM-MN]

Has anyone ever experienced significant miss with their OG while doing extract? I'm talking hitting 1.020 when trying to hit 1.040. I brewed a batch of Northern Brewer Cream Ale this afternoon and am beyond pissed it missed the mark so badly. I'm not a new brewer and have made plenty of extract beers (and PM and AG on top of that) and never had such a miss with OG.

I did a couple things different today than usual, but wouldn't expect such a drastic change. I brewed on stovetop instead of on propane burner (because it's f-ing hot in TX and I was working-from-home), which led to a much slower boil. It took FOREVER to even reach boil. Starting volume was 3.5 gallons, post-boil volume was ~3.25 gallons, which I then topped off to 5. (I know, I should have taken hydrometer reading prior to topping off, but can't go back in time.) I even used used hot water to rinse all of the LME out of the container and into my boil kettle, so I'm sure I got all the sugars in the wort. I've read the OG on 3 different devices and got comparable results, so I don't think it's an issue with my instruments.

Traditional Hydrometer: 1.018
Refractometer: 1.024
Tilt Hydrometer: 1.022

I read one article that said sugars can sink to the bottom and impact the OG reading. Is it possible to be off by that much? I've shaken the bejesus out of the fermenter and had little impact on the OG. I've run the numbers through several calculators and it's as though I used half the LME I should have, even though I'm sure I used all 6 lbs. (+1 lbs. of specialty grains, although I haven't included them in calculations since they shouldn't impact OG significantly).

Any thoughts on what would cause the OG to be so far off? And other question, what to do now? I ran the numbers and it looks like if I add another 4 lbs. LME in 1 GAL of concentrated wort that should correct the issue, right? Any help is much appreciated. Thanks!

If you used all the extract you got the advertised OG. The concentrated wort is much denser than the top off water that getting it to mix thoroughly takes some vigorous stirring. It's such a common occurance that there is a sticky post in the beginners forum. I've come to recommend that extract brewers do not take the OG reading and just go by what is on the kit.

 

[VikeMan]

Here's a pretty exhaustive list of reasons (alone or in combination) for getting a gravity reading significantly lower than expected with an extract batch. (You may have already eliminated some of them.)

- You didn't get all the extract into the kettle (LME stuck in the jug?)
- You topped off with water to more than the target volume
- You didn't mix the top-off water with the wort thoroughly before measuring the OG
- You measured the OG while the wort (and top off water) was still hot, and didn't adjust the reading for temperature.
- Some wort was left behind in the bottom of the kettle, so more water was used to top off to reach the target volume.
- Your Hydrometer is inaccurate (try checking it with plain water)
- Operator error on the gravity reading
- Recipe/Software problem

I suppose it's possible to get a bad batch of LME, but I've never heard of that happening before.

 

[BrewnWKopperKat]

Any help is much appreciated.

If you don't make adjustments, there is a way to approximate OG with a hydrometer and refractometer.

Approximate ABV and Original Gravity from current Brix and Gravity converter
www.northernbrewer.com/pages/refractometer-calculator

 

[Jimbutler21]

Well, I panicked too early. Checked it again this morning and it was up to 1.030 and again around noon and it was up to 1.037. Thanks for the feedback!

Not going to lie, I've never seen the OG be off by that much with dilution. Learn something new each brew I guess. Thanks everyone!

 

[myndflyte]

Sounds like the extract just wasn't fully mixed. Same thing can happen when doing all grain and you take a pre-boil reading after sparging without mixing well.

 

[davidabcd]

(I know, I should have taken hydrometer reading prior to topping off, but can't go back in time.)

Everyone else covered anything I might have suggested. Looks like you're on track now, so that's good.
Anyway, I noticed your statement I quoted from you and I was curious as to what the benefit would be to a gravity reading prior to topping off an extract batch?
Thanks.

 

[kartracer2]

Anyway, I noticed your statement I quoted from you and I was curious as to what the benefit would be to a gravity reading prior to topping off an extract batch?

As an extract brewer I haven't done that my self but I suppose if know your post boil vol. and SG, figure your needed top-off vol, you can run the numbers through a dilution calc and find a check and balance number. Just spit balling here,,
Cheers,
Joel B.

 

[NGD]

As an extract brewer I haven't done that my self but I suppose if know your post boil vol. and SG, figure your needed top-off vol, you can run the numbers through a dilution calc and find a check and balance number. Just spit balling here,,
Cheers,
Joel B.

I do this. I prepare a few gallons the day before and store them either in an ice chest or a mini fridge. Once my boil is done, I calculate how much volume I need to add for desired OG. Cool with IC for a bit then add pre-cooled volume. Gets me close to pitch temps in a fairly decent time.

 

[Brewer dad]

So I had the opposite of the OP's experience yesterday, way overshot target OG. Brewed a morebeer Irish red ale extract kit, target is 1.046-50. I got 1.086. Followed directions and didn't add anything.

After reading this and other threads, I'm thinking it might be a similar issue where it needs time to come together. My wort was 2.5 gal, with some minor loss from boiling. I already had 1 gal water in fermenter, and added wort on top of that. Then topped up more water to 5 gal. Since I took OG just after this, I'm wondering(hoping) it's because the denser wort was sitting on the bottom and hadn't been able to fully mix with the water. I might take another reading today, but plan on letting it ride.

 

[jrgtr42]

The thing about extract brewing is that a given amount of extract, mixed thoroughly in a given amount of water will always add up to the same OG.
For the |OP, guessing the sample was from the top, and not mixed.
For the second - BrewerDad, I wonder where you took the sample from - is there a spigot in your bucket you took from? Or a siphon? From the top? From the bottom? Guessing you took from nearer the bottom, without mixing.
Over time, even unmixed will mix up and become uniform in there, but it takes time.

 

[Brewer dad]

Yes sir I'm using a fermonster with a spigot, so sample was taken from bottom. No mixing other than pouring water in.

Thanks!

 

[jrgtr42]

Yes sir I'm using a fermonster with a spigot, so sample was taken from bottom. No mixing other than pouring water in.

Thanks!

To quote the Mythbusters... "well there's your problem right there."
yeah, the denser, thicker wort at the bottom didn't get mixed in with the top-off water, giving you a higher reading.

 

[wsmith1625]

I know you were in the kitchen for this batch, but when you get back on the propane burner I would recommend doing full volume boils with no top off in the fermenter.