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OG Lower than expected - what now?

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darrenbrews

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Hey all,

Today I did my first homebrew that was not a MR Beer kit, and it was the first time I took OG readings and actually had to rack my beer with the racking cane. Interesting day.

Anyhow, my recommended OG was 1.048-1.042, but the reading I got was 1.042. What ramifications could become of this lower OG?

Also when you guys are transferring from the brew pot to the primary how do you filter out all the trub. I transferred with the cane, then once at the bottom I tried to filter the trub with a strainer, but in the process I think I lost a quart of beer (not quite 5 gallons in my primary). What do you do?

-DZ
 

241

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1.) You are right at the bottom of the recipe gravity. Yay! Still within spec. You will be on the lower end of the alcohol level but no biggie. Maybe next time if you do the same recipe boil a few minutes longer.

2.) I might be the wrong person to ask but I dump all of my kettle into the fermenter and worry about filtering it out while racking to secondary or racking to bottling bucket later. I like to enjoy my brew day and I don't enjoy filtering through trub or potentially losing total drinkable beer volume.
 

RM-MN

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I'm another trub dumper. I don't notice anything going wrong with that, no off flavors and I get all my beer. The trub settles to the bottom of the fermenter and I rack above it to the bottling bucket. If I happen to suck up a little trub it settles in the bottling bucket while I am getting ready to start bottling and stays there.
 

ajf

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Did you do a full boil, or top off with water? If you topped off, then you probably had a higher OG than you measured because it is very difficult to thoroughly mix the top off water with the wort.

I wouldn't worry at all about losing 1 qt beer when transferring to the fermenter. I have a kettle with a false bottom and a spigot, and use whole hops. To transfer to the fermenter, I just drain through a CFC, and the hops on top of the false bottom capture most of the hot break (although I get all the cold break in the fermenter). On a typical brew with about 3 oz hops, I lose about 1.5 qt to hop absorption and trub. I don't worry about it. I usually lose a bit more when I keg because the keg won't quite hold everything in the fermenter.

-a.
 
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darrenbrews

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my recommended OG was 1.048-1.042,
Actually I meant that my recommended OG was 1.048-1.052 but I came in at 1.042.


Did you do a full boil, or top off with water?
I topped off with water, I was wondering if this could have been an issue with OG reading.


did you take your reading at the correct temp.(mine needs temp to be 62*) just checking.
Directions said 70 degrees , so that's what I did but might have been 1-2 degrees off though, would that matter?
 

freisste

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There's a solid chance the wort wasn't completely mixed with the top off water and you measured a watery part.

Yes, temp matters when measuring gravity. Your hydrometer should have come with a piece of paper explaining what the temp should be and how to correct if you are off of that temp. Also, on the bottom of the hydrometer, there should be a couple numbers (60/60, maybe?) which are the temp you should measure at and the temp it was calibrated at, respectively.
 

beaksnbeer

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Actually I meant that my recommended OG was 1.048-1.052 but I came in at 1.042.



I topped off with water, I was wondering if this could have been an issue with OG reading.



Directions said 70 degrees , so that's what I did but might have been 1-2 degrees off though, would that matter?
Yes both of this will change your reading, BUT chances are your mash temp was off so you didn't get full conversion.
 

freisste

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beaksnbeer said:
Yes both of this will change your reading, BUT chances are your mash temp was off so you didn't get full conversion.
Was this pm or AG? I assumed it was extract. Didn't actually see it mentioned anywhere, though. If you mashed, that leads to more possibilities as to why you reading was off of your expectations.
 

zeg

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Do check whether your hydrometer is calibrated for 60° or 68° (I think those are the two, not sure about the second). It's good to know.

However, it can't be the problem here. The correction for 10-15° is only 0.002 or so---so if you were at 70°F on a 60°F hydrometer, your real reading would have been 1.044. That's still low.

The mixing theory is a good one. I came out way low on a batch and found it was due to poor mixing, even after very thorough shaking. The denser stuff settles toward the bottom, so gravity samples taken by turkey baster or wine thief tend to be low.

There are a few effects that this could have, assuming it is actually low. Which of these you may be affected by depends on just why you came out low. Spoiler: None are worth worrying about.

First, and most obvious, your ABV will come out about 1% lower. No biggie, 1.042 is a perfectly respectable SG.

Second, your beer may have a thinner body than intended, since you have less "stuff" in there. Also no biggie.

Third, you may have slightly more bitterness than expected, since wort gravity is connected to hops utilization. (The currently favored theory is that it's not exactly because of the gravity, but that's a big and not entirely settled topic.)

Finally, there are a bunch of very subtle effects that may crop up, which you should worry about even less than the above (which you also shouldn't worry about). Your color may be a bit lighter than you planned. Assuming you did PM, your malt flavor balance will be affected (the low gravity will almost surely be due to the mash, so the extract will be a larger than intended fraction of the grain bill). Etc...

[edit]
Just saw that this was extract+steeping. Ignore most of what I said above. Unless you left a lot of what you thought was mostly trub behind in the kettle or diluted by about 25% too much, it's just due to incomplete mixing and your gravity is fine.

There's no efficiency to consider with extract, so it'd just be the efficiency on the steeped grains. Unless there was a very large quantity of those, your efficiency from the steep won't vary enough to make that kind of error.
 

Qhrumphf

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Yes both of this will change your reading, BUT chances are your mash temp was off so you didn't get full conversion.
Given that A) he topped off and B) he said this was his first beer that wasn't Mr. Beer, I think we can assume this was an extract kit.


Revvy has a thread on here describing why with extract beers, gravity will be right. Assuming that you added the correct amount of fermentables, and the volumes are correct, then the gravity reading will be right. There's no variance with extract, since the sugars in extract do not change.

https://www.homebrewtalk.com/f39/at...inal-gravity-reading-wrong-dont-panic-289735/

Granted I do all grain, but I'm also required to do partial boil due to restriction to an old electric stove. There's a very easy trick to not have to second guess your gravity reading. All you need to be able to do is accurately measure the volume of wort that you have before you top off. If you know the current volume before you top off, take a gravity reading, and use the reading as "gravity points" (ie 1.065 would be 65, 1.042 would be 42, and so on). Gravity 1 x volume 1 = gravity 2 x volume 2. If you're doing a 5 gallon batch, and have 2.5 gallons of wort at 1.080, it would be 2.5(80)=5(gravity), or 40. So if you top off to 5 gallons, your OG will be 1.040. If you're aiming for a certain gravity instead of volume, you can use it to see what you need to top off to. This is the same math that's used in all-grain brewing when taking a pre-boil reading, and it's the same math use in volume conversion calculators online.


As for the trub, 90% of the time I just dump it all in the fermenter. The exception being when I'm using a substantial amount of hops, or leaf hops. In that case, I strain en route to the fermenter. There are arguments on either side as to whether the trub in the fermenter is good or bad, but of all the experiences I've seen, it makes no measurable difference either way. The one exception is when using something like a plate chiller (and perhaps CFC, don't know cause I use an immersion chiller), where the trub and hop debris will clog the chiller.
 
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darrenbrews

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Thanks for the information everybody. Although an easy brew, I learned a lot from doing it. I think I'll do another easy extract kit like this one before moving onto something more challenging. I made a few dumb mistakes i.e., disregarding temperature when I took my OG. I even knew better but got all caught up in the overall process and forgot that important detail.

Anyhow, it all went well overall and I think I'll have an OK beer. At this point I'm just happy to see my airlock bubbling.

-DZ
 

zeg

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That's what the first brew is all about. It's rare for the first one to be any more than "OK" (objectively speaking. I know with mine, even though it was just OK, to me it was awesome)
 
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