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Poor Sg Before And After Boil

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hellbent

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Just done a 14l Dr Smurto GA and got some weird results. My 3kg/ 9ltr mash went in @ 75c and came out at 64c which wasn't bad. I then done a sparge/rinse with about 12 ltrs water @ 85c (realised later that Brewmate reckoned 10l as correct amount) so after the sparging/rinsing I finished up with a lowly SG of 1.028 @ 56c instead of recommended 1.045 then after Boil I added another 3 ltrs water to bring it up to 14ltrs and got a after boil SG reading of 1.030 @ 65c instead of recommended 1.047. May I ask 5 things of you wise gentlemen......
1. Would the extra 2 ltrs in Sparge matter?
2. Should I have taken the SG after the boil and before adding the 3 ltrs of water??
3. The brew is cooling now and as I have 1kg bag of dextrose in my collection I wondered if I mixed that into boiling water and added it to try and lift it a bit and give it more guts.
4 I also have a 1.7 kg can of Coopers real Ale here, could I add that to some boiling water and add that in to lift it up....
5. Just leave it as is and add the yeast when it cools to 22c and enjoy it as a light beer.

Thanks Guys and appreciate any help given because I am at a loss here
Al

:beer:
 

Lecterfan

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Using beersmith to adjust for temperature (which I'm not sure you've done) - 1.030 at 65c is an ACTUAL specific gravity of 1.048 if your hydrometer is calibrated for 20c.

Sounds like you hit your marks and haven't adjusted hydro readings for temperature.
 

Nick JD

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DON'T ADD ANYTHING! :D

14L of 1.049!

Hot liquids aren't floaty!
 

The Village Idiot

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Dumb question, do the readings of a refractometer need to be adjusted for temperature????

I have been a little "short of the mark" before and after the boil.



Peter

Using beersmith to adjust for temperature (which I'm not sure you've done) - 1.030 at 65c is an ACTUAL specific gravity of 1.048 if your hydrometer is calibrated for 20c.

Sounds like you hit your marks and haven't adjusted hydro readings for temperature.
 

QldKev

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Dumb question, do the readings of a refractometer need to be adjusted for temperature????

I have been a little "short of the mark" before and after the boil.



Peter

Yes, they are normally calibrated for 20c

Since you are dropping only a small sample on there, the sample's temp drops a lot. Often still not all the way down to 20c.

I always rapidly cool the sample by dipping the end of the pipet in cool water for a minute or so. I then leave the sample at room temp for at least 10min before checking it.

QldKev
 

Nick JD

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The drop should cool pretty much instantly as it his the refractometer glass.

EDIT: Geez I hope Al didn't dump a can of goop into his perfect DSGA (with better than expected efficiency)!
 

Malted

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Dumb question, do the readings of a refractometer need to be adjusted for temperature????
Some refracs are ATC (automatic temperature calibration). Mine is, yours might not be.
Even though mine is ATC, when I put wort from the kettle on it, the gravity will come up a couple of points if I let it sit for a while.
It's a cheapy from eBay, it needs to be calibrated every now and then for zero (I use cooled, boiled, filtered, water, not best practise but why would I buy distilled water for just a millilitre or two of it?).
 

Lecterfan

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Off topic - for the sake of consistency, I deleted an erroneous post of mine that misread the second question. Apologies.
 

hellbent

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The drop should cool pretty much instantly as it his the refractometer glass.

EDIT: Geez I hope Al didn't dump a can of goop into his perfect DSGA (with better than expected efficiency)!
Ah now Nicky me boy, Al DIDN'T dump any goop into it, he instead asked the wise people like your self before any drastic measures were taken. :)
 

Nick JD

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Ah now Nicky me boy, Al DIDN'T dump any goop into it, he instead asked the wise people like your self before any drastic measures were taken. :)
Phew! :D And remember to up your efficiency on your software to allow for getting 1.049 and not 1.045.
 

hellbent

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Using beersmith to adjust for temperature (which I'm not sure you've done) - 1.030 at 65c is an ACTUAL specific gravity of 1.048 if your hydrometer is calibrated for 20c.

Sounds like you hit your marks and haven't adjusted hydro readings for temperature.

I did use the brew calculator described in Nicks BIAB tutorial for my SG readings but made one mistake, I entered Celcius temps and not Fahrenheit.
Thanks for your help mate.
Must look into this calibration for a hydrometer though , never heard of that before.
 

Guysmiley54

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Slightly OT but my Refrac often reads low. I have calibrated but it still reads lower than my hydro. I seem to remember MHB explaining something about a reason why wort could a slightly lower reading... Can anyone help my foggy memory?

PS I am aware about temp changing the reading and do find that after a minutes mine goes up too.
 

felten

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I think it's because the refracts are calibrated for sucrose not maltose. You can't trust the SG scale if you have a model with one. And to get a 'proper' reading for your wort, you have to input the brix value into some software and it will apply a correction value.

Not sure if that's what you mean or not.


I've noticed if you're a forgetful bugger like myself, and leave the sample on the plate for too long it will evaporate and you'll get a really skewed reading. I leave it for 30s max for the temperature to equal out (with ATC), then take a reading.
 

felten

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Do you use beersmith? that has a refractometer tool built in. No need to compensate, just enter the brix value into the software and it does it for you.
 

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