How do you miss OG w/ extract?

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redawg77

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I'm on my 10th or so batch of beer. I'm still working my way up, adding equipment as I go... I'll be doing all grain this time next year, but for now I'm still trying to improve my methods with extract.

I haven't been the best about checking my gravities, but made it a point to check OG and FG before my most recent brewday. Much to my dismay, I missed my kit-predicted OG of 1.049-1.051... my reading was 1.040. The question is... what factors could have lead to this big of a miss? This kit (ture brew american wheat) came with 2 cans of liquid malt extract and 1 oz. of hops (30 min boil, no steeping grains)... hard to screw that up. I scraped every last bit out w/ a spoon. I had zero burnt extract on the bottom of the pot - It was all dissolved into the wort while off the burner. I followed the kit instructions to a T. I took the OG sample after shaking the better bottle to aerate, but before pitching (of course). I originally suspected the hydrometer to be faulty, but I tested it in water and came close enough to 1.000 to bust that hypothesis.

I'm just puzzled as to how one can miss OG with extract kits, assuming they don't leave out any additions, and use measure everything properly (5 gallons total). Old extract? I will say that this was a boxed kit from my local brewshop, which doesn't do a whole lot of business. So it's likely it'd been there a while.

Any input appreciated. I'm not too worried about it, as I'm sure I'll end up with some tasty beer... was just curious.
 
The usual suspects are (1) incomplete mixing of the wort and top-off water (2) bad volume measurements (3) miscalibrated hydrometer (4) failure to adjust hydrometer readings for temperature

Sounds like you've ruled out 1-3. What was the temp when you took your hydro readings, and at what temp is your hydrometer calibrated?
 
I got it down to 75 before adding the wort and top-off to the fermenter and shaking, so I was in the neighborhood of that. Now that I think about it a bit more, I may have been a little heavy on the top-off water. I have a 6 gallon better bottle, and I measured the 5 gallon mark based on a post I saw somewhere (about a 3rd of the way down the top rib). I'll probably measure out 5 gallons precisely and mark it on the BBs.

Thanks for the quick reply.
 
I got it down to 75 before adding the wort and top-off to the fermenter and shaking, so I was in the neighborhood of that. Now that I think about it a bit more, I may have been a little heavy on the top-off water. I have a 6 gallon better bottle, and I measured the 5 gallon mark based on a post I saw somewhere (about a 3rd of the way down the top rib). I'll probably measure out 5 gallons precisely and mark it on the BBs.

Thanks for the quick reply.

If your hydrometer is built to read at 60F then 1.040 is actually 1.042 at 75F.
 
gotcha... it is indeed a 60 deg hydrometer. I didn't realize they were so sensitive to temperature. I guess I'd know that if I'd been more diligent with my readings up to this point. Thanks guys. At this point, I'm concluding that it's a combination of a warm reading and a little too much top-off.
 
I don't think you've ruled out #1 yet. You have to mix the crap out of a partial boil with top off. Shaking to aerate isn't enough unless you shook it violently for 10 minutes. its THAT much of a pain to mix the two.

maybe it was a little too much top off water, but mixing is a pain. you might try a drill driven wine degasser. That'll mix a lot more quickly.
 
I don't think you've ruled out #1 yet. You have to mix the crap out of a partial boil with top off. Shaking to aerate isn't enough unless you shook it violently for 10 minutes. its THAT much of a pain to mix the two.

maybe it was a little too much top off water, but mixing is a pain. you might try a drill driven wine degasser. That'll mix a lot more quickly.

Thanks Malkore... I have a follow-up to that. Assuming I did not mix the top-off water sufficiently, will this ultimately affect the flavor of my beer, or will the fermentation activity distribute the beer composition evenly?

That said, most of the beginner how-tos I have read say that the action of pouring the wort into the top off water should mix effectively. I was always suspicious of that, and always stir (bucket) or shake (bb carboy) to more effectively mix my batches up.
 
Thanks Malkore... I have a follow-up to that. Assuming I did not mix the top-off water sufficiently, will this ultimately affect the flavor of my beer, or will the fermentation activity distribute the beer composition evenly?

That said, most of the beginner how-tos I have read say that the action of pouring the wort into the top off water should mix effectively. I was always suspicious of that, and always stir (bucket) or shake (bb carboy) to more effectively mix my batches up.

Hi! As a beginner and so far extract-only (some partial mash) I had had the very same questions you do. The responses I received are almost exactly what I was told when I asked about missing my OG on pretty much every single batch. Mixing really is a huge pain (and that can't be overstated). The closest to the proper OG I ever got on a batch was after the most shaking of a carboy I had ever done...I broke a decent sweat and after almost 10 straight minutes STILL didn't get the OG quite to where I wanted it but it was close.

The process of fermentation causes its own whirpooling/swirling effect once on the yeasties start doing their thing. And the yeasties love to eat so whether or not you mix well enough to begin with, the little guys will find the fermentables one way or another. In my (limited) experience the beer will turn out just fine. It may also be worth noting that even though none of my OGs have been accurate all of my FGs have hit the mark, despite the mixing issue.

I have been looking for a device to connect to a power tool to do my mixing just so I can hit an accurate OG for once. I found those wine degassers mentioned before but just can't justify the $30 plus shipping (my LHBS doesn't carry them). Then again, since all of my batches have come out OK I'd say it's really not a necessity...I'd say don't both if you'd prefer to spend the money elsewhere.

Hope this helps! Anyone can feel free to correct me if I have misstated anything! Wouldn't want to lead anyone astray with my relative inexperience...
 
Hi! As a beginner and so far extract-only (some partial mash) I had had the very same questions you do. The responses I received are almost exactly what I was told when I asked about missing my OG on pretty much every single batch. Mixing really is a huge pain (and that can't be overstated). The closest to the proper OG I ever got on a batch was after the most shaking of a carboy I had ever done...I broke a decent sweat and after almost 10 straight minutes STILL didn't get the OG quite to where I wanted it but it was close.

The process of fermentation causes its own whirpooling/swirling effect once on the yeasties start doing their thing. And the yeasties love to eat so whether or not you mix well enough to begin with, the little guys will find the fermentables one way or another. In my (limited) experience the beer will turn out just fine. It may also be worth noting that even though none of my OGs have been accurate all of my FGs have hit the mark, despite the mixing issue.

I have been looking for a device to connect to a power tool to do my mixing just so I can hit an accurate OG for once. I found those wine degassers mentioned before but just can't justify the $30 plus shipping (my LHBS doesn't carry them). Then again, since all of my batches have come out OK I'd say it's really not a necessity...I'd say don't both if you'd prefer to spend the money elsewhere.

Hope this helps! Anyone can feel free to correct me if I have misstated anything! Wouldn't want to lead anyone astray with my relative inexperience...

Thanks Bri. I appreciate the reply. I figured it would be OK, since my previous batches were equally mixed most likely and turned out great for the most part, so I wasn't too concerned. That said, it's always nice to hear some words of comfort when you've got 5 gallons quietly gurgling away in the fermentation chamber.
 
I don't think you've ruled out #1 yet. You have to mix the crap out of a partial boil with top off. Shaking to aerate isn't enough unless you shook it violently for 10 minutes. its THAT much of a pain to mix the two.

maybe it was a little too much top off water, but mixing is a pain. you might try a drill driven wine degasser. That'll mix a lot more quickly.

Ok, quick question (not to be obnoxious, I'm just wondering): if improper mixing is the cause of many too-low gravity measurements, shouldn't one see just as many too-high gravity measurements? As I understand it, if the wort and the top-off water are improperly mixed, then most likely it's more water nearer the top of the fermenter, and more wort neat the bottom, since wort has, well, a higher gravity than water.

But if you've just shaken the fermenter up for a few minutes and stick your turkey baster or wine thief or whatever deep enough in there, isn't there as much of a chance (or even more of a chance, if the ratio of wort to top-off water is greater than 1) that the hydro sample you end up with will have more wort than water in it, and will therefore give you a higher OG than is really the case?

Also, really - 10 minutes? Jeez, that'll kill the back. :eek:

Maybe it's time to just bend up a coat hanger, sanitize, plug into a drill and go to town.
 
First Post! I figured I would just reply and keep this thread going since its exactly what my question entails except I am doing full boils will extract kits and missing my OG's. It has happened on my last 3 brews and all by a considerable amount (est. 1.099 act. 1.089, 1.095 vs 1.083, 1.052 vs 1.0445). All of those were temperature corrected. Am I not getting enough boil-off when I brew? I measure exactly 6gallons, seem to get a pretty full, rolling boil going and never use a lid once the boiling starts. Any ideas? Should I use less starting volume and if so how much less? Thanks in advance.

Also, I just want to say this site has been a huge help. You never realize how terrible your process is as a beginner until you search through the threads on this site. My brews since joining/reading this aren't mature yet but I am sure they will be leaps and bounds better than my first 4 or 5 batches.
 
Ok, quick question (not to be obnoxious, I'm just wondering): if improper mixing is the cause of many too-low gravity measurements, shouldn't one see just as many too-high gravity measurements? As I understand it, if the wort and the top-off water are improperly mixed, then most likely it's more water nearer the top of the fermenter, and more wort neat the bottom, since wort has, well, a higher gravity than water.

But if you've just shaken the fermenter up for a few minutes and stick your turkey baster or wine thief or whatever deep enough in there, isn't there as much of a chance (or even more of a chance, if the ratio of wort to top-off water is greater than 1) that the hydro sample you end up with will have more wort than water in it, and will therefore give you a higher OG than is really the case?

Also, really - 10 minutes? Jeez, that'll kill the back. :eek:

Maybe it's time to just bend up a coat hanger, sanitize, plug into a drill and go to town.

I think it might depend on how you're taking your sample. I've never used a turkey baster, wine thief, or the like. I just pour straight from the carboy into a measuring cup thereby probably getting a less dense liquid since the sample is taken from the top. My guess would be a lot of beginners do it the same way which may account for most of the low OG readings. You may have a point when you talk about taking a sample deeper into the carboy. Makes sense to me, just haven't personally tried that...might have to do a little experiment...
 
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