I Really Don't Get Gravity

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leevalentine001

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Good morning,

I've been doing weekly batches (mostly of cider lately as everyone seems to love it and it's super easy).

The last beer I did a couple of weeks back had an original gravity of 1.037 and ending of 1.010. Most calculators estimate that to only be about 3.6% (.5% after priming maybe).

For some reason, this particular brew (simple kit and kilo with added vanilla and maple syrup) knocked the socks off everyone who tried it. The first 750ml bottle would be enough to get any of my mates feeling pretty drunk (equiv of about 3 750ml bottles of normal beer).

My ciders usually have an OG of 1.050 and FG of 1.010 and they usually don't get a person drunk anywhere near as fast as that.

One other thing I don't get about gravity is how it actually seems to rise for the first 24 hours (as in the number gets higher). I pitched a cider yesterday constantly mixing the wort thoroughly to ensure it was a consistent viscosity. I took an OG of 1.040 (two tubes full and both exactly the same reading). This morning I took another reading of 1.044. How does that work? And how do I calculate the abv once it's ready to bottle? Using the 1.040 or 1.044 as the OG? And who's to say it didn't rise to 1.050 at some point and is now back down to 1.044 since then?

Usually the exact same kit + kilo gets a cider an OG of 1.050 so it was odd that it read 1.040 at first this time. Am I doing something wrong or does this sorta thing happen to everyone?

Lee
 

geneabovill

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It could rise from CO2 bubbles clinging to the hydrometer. Temperature also affects the reading.
 

stux

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Good morning,

I've been doing weekly batches (mostly of cider lately as everyone seems to love it and it's super easy).

The last beer I did a couple of weeks back had an original gravity of 1.037 and ending of 1.010. Most calculators estimate that to only be about 3.6% (.5% after priming maybe).

For some reason, this particular brew (simple kit and kilo with added vanilla and maple syrup) knocked the socks off everyone who tried it. The first 750ml bottle would be enough to get any of my mates feeling pretty drunk (equiv of about 3 750ml bottles of normal beer).

My ciders usually have an OG of 1.050 and FG of 1.010 and they usually don't get a person drunk anywhere near as fast as that.

One other thing I don't get about gravity is how it actually seems to rise for the first 24 hours (as in the number gets higher). I pitched a cider yesterday constantly mixing the wort thoroughly to ensure it was a consistent viscosity. I took an OG of 1.040 (two tubes full and both exactly the same reading). This morning I took another reading of 1.044. How does that work? And how do I calculate the abv once it's ready to bottle? Using the 1.040 or 1.044 as the OG? And who's to say it didn't rise to 1.050 at some point and is now back down to 1.044 since then?

Usually the exact same kit + kilo gets a cider an OG of 1.050 so it was odd that it read 1.040 at first this time. Am I doing something wrong or does this sorta thing happen to everyone?

Lee
Basically, you are having calibration or hydrometer usage issues

Gravity doesn't increase during fermentation, but you do need to either take the gravity at the calibration temperature (20C) or adjust the reading. Also you may not be using the hydrometer correctly
 

Ross

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OG never rises.. Despite your best efforts, your OG measurement was incorrect due to it not being adequately mixed.
As to the beer that knocked everyone about, again you may have incorrect readings, but without you listing ingredients & quantities, no-one can check it for you.

Cheers Ross

Edit:

As pointed out the readings may be due to temp differences as well, but with the size of difference I'm still leaning towards poorly mixed.

Cheers Ross
 

tricache

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It could rise from CO2 bubbles clinging to the hydrometer. Temperature also affects the reading.
Yep, two of the biggest ways it changes...give your hydrometer a spin and make sure it has no bubbles on it and just check your temps between batches and readings
 

leevalentine001

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Yep, two of the biggest ways it changes...give your hydrometer a spin and make sure it has no bubbles on it and just check your temps between batches and readings
Thanks for all the replies. It's definitely not a CO2 issue cause I spin the hydrometer for ages and let it sit a few minutes before checking it. I didn't know the temperate could make a difference. I think it was high 20's when I took the first reading of 1.040 and it was 20 on the dot this morning when I got 1.044.

As for the strong beer, I did mention the ingredients but I wasn't exact. It was a coopers lager can with 1kg brew enhancer 2 (coopers also). 250ml pure maple syrup and 3 tsp of vanilla paste (which I was stupid enough to simply scoop into the wort just before adding the yeast so it didn't dissolve).

Doesn't seem likely that it would be much higher than 4-5% but it had the same effect on 6 different people at different times (as in, different days).

I've tested my hydrometer in water recently and it was right on 1.000 so I gather it's calibrated okay. And I know it's impossible to prove this but it was mixed extremely well, my arm was aching by the end of it (mixed from the moment the first ingredient was added right until after adding the yeast + nutrient).

This only applies to the one I pitched yesterday though, all the ones I did before this weren't mixed very well (including the potent beer). So the OG of 1.037 or whatever may have been wrong, but it was the only home brew I've ever had that was substantially more potent (or seemed to be) than normal.
 

Liam_snorkel

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I think it was high 20's when I took the first reading of 1.040 and it was 20 on the dot this morning when I got 1.044.
if your hydrometer is calibrated to 15deg, 1.040 at 30deg is about1.044
if it's calibrated to 20deg, 1.040 at 30deg is a bit over 1.042
 

leevalentine001

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if your hydrometer is calibrated to 15deg, 1.040 at 30deg is about1.044
if it's calibrated to 20deg, 1.040 at 30deg is a bit over 1.042
How do I test what temperature it's calibrated to? Just test the water temperature when it's reading 1.000?
 

Liam_snorkel

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yep. have a close look at your hydro first, it might be printed on it.
 

carniebrew

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As for the strong beer, I did mention the ingredients but I wasn't exact. It was a coopers lager can with 1kg brew enhancer 2 (coopers also). 250ml pure maple syrup and 3 tsp of vanilla paste (which I was stupid enough to simply scoop into the wort just before adding the yeast so it didn't dissolve).

Doesn't seem likely that it would be much higher than 4-5% but it had the same effect on 6 different people at different times (as in, different days).
Certainly with those ingredients, filled to 23 litres, it wouldn't be any more than about 4.0% after bottle conditioning. Roughly an OG of 1040 and FG of 1014, which is close enough to what you said you got with your readings.

Can't imagine how that beer would knock anyone's socks off, should be a right quaffer at those numbers. Even with the FV filled to only 16 litres you'd be talking about a 5.7% beer, still not enough to blast you after 1 tallie. And besides, you're FG would be more like 1020 with 16 litres, so it wouldn't be that either.

There's always something....making beer is simple enough, kit beer even simpler....the explanation will be somewhere in what you've done.
 

leevalentine001

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Yeah I was racking my brain as to what it could be. Everyone who was drinking it said it felt like a 7% or higher drink. And these guys all drink frequently enough to know how much usually gets them tipsy / drunk.

I even wondered if somehow it was just absorbing more of the alcohol into the blood (instead of pissing it out?). Chemistry can do some pretty weird stuff.

On that note, I'm actually interested in how to make strong (6-7%) beers. One would think that you would just double up on the sugar and pitch more yeast. But I doubt it will be that simple. Anyway this is for another topic, I'll have a look through the forum and see what I can find from past posts.
 

carniebrew

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On that note, I'm actually interested in how to make strong (6-7%) beers. One would think that you would just double up on the sugar and pitch more yeast. But I doubt it will be that simple. Anyway this is for another topic, I'll have a look through the forum and see what I can find from past posts.
Very easy to do if you use IanP's spreadsheet to design your beers. But i'd up the malt extract rather than just sugar to ensure more body in your brew. You shouldn't need more yeast for 6% beer, but if you're getting up over 7% look into yeast starters and the like.
 

mrkitewhitey

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Don't worry though,..,.. Gravity only brings you down.,
;)

Sorry, couldn't resist
 
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