Gravity readings (SG) and efficiency calculations

[marnel]

I'm pretty sure i'm over thinking things and confusing myself left and right and after searching and reading all the mixed responses all over the internet and this forum.

The last couple of brews i've done ( new system ) i've missed my final target volumes into the fermentor and topped off to meet 5 gal. So i have a couple questions regarding gravity and efficency calculations.

1) i'm pretty sure extract efficency is calculated once collection has finished in the BK.

2). Brew house efficency would be calculated once the wort has been collected into the fermentor, where things get fuzzy for me is would you calculate this before or after topping off?

3). This is kinda along the same lines as question 2 but slightly different. When measuring starting gravity my feelings have always been that the gravity reading should be taken after topping off but for somereason i am now questioning everything i thought i knew.

Thanks for reading

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[73Drvr]

It doesn't matter when you take the measurement. I would guess most people do it after the boil. But as long as you are only adding water the math should work out the same.

 

[surferdrew]

I'm pretty sure i'm over thinking things and confusing myself left and right and after searching and reading all the mixed responses all over the internet and this forum.

The last couple of brews i've done ( new system ) i've missed my final target volumes into the fermentor and topped off to meet 5 gal. So i have a couple questions regarding gravity and efficency calculations.

1) i'm pretty sure extract efficency is calculated once collection has finished in the BK.

2). Brew house efficency would be calculated once the wort has been collected into the fermentor, where things get fuzzy for me is would you calculate this before or after topping off?

3). This is kinda along the same lines as question 2 but slightly different. When measuring starting gravity my feelings have always been that the gravity reading should be taken after topping off but for somereason i am now questioning everything i thought i knew.

Thanks for reading

Sent from my iPhone using HB Talk

In regards to answering your question, I want to be on the same page with terms.

Technically,
SG= Specific Gravity (not starting gravity), a measurement of the density of liquid...water is 1.000 SG
Pre-boil gravity= measuring the SG after mashing and before boil (essential in AG brewing)
Post-boil gravity= measuring the SG after the boil (if it's too low, keep boiling. Too high, top off with water to get desired OG)
OG= Original Gravity (specific gravity reading when you add your yeast)
FG= Final Gravity (specific gravity reading when fermentation is complete)

Mash efficiency has to do with how efficient you were at getting gravity (sugars) out of the grain during the mashing process.

OG would be measured after/if you top off.

Here's a great resource: http://homebrew.stackexchange.com/questions/1434/wiki-how-do-you-calculate-original-gravity

 

[marnel]

Yes we are on the same page as far as terms I'm not sure why i put sg in parens maybe just to scatter brained lol.

So what would your procedure be for calculating brewhouse efficency, or the efficincey of your system and procedures as a whole be? Would you measure before topping off or would the fact that you had to top off be calculated in to that for accuracy, in my head i can create arguments for both ways :-S

I know my mash efficency but overall i care more about my brewhouse efficincy i think.

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[ajf]

If you are topping off, I wouldn't take an OG reading until I had really mixed the top off water with the wort.
Other people say you should stir the crap out of the wort, but I am very careful not to introduce crap into the wort in the first place.

-a.