Question on gravity readings

[harrymanback92]

So as I understand a gravity reading (in regards to beer making) is a way of essentially measuring sugars in the solution( water). Am I right to assume that a gravity reading of 1.040 is saying there's 4 grams of sugar in the sample? Or 40 grams? Or am I just completely off base?

 

[MisterTipsy]

You are off base. If not, 1000 gallons of 1.040 beer would have the same amount of sugar as 5 gallons of 1.040 beer.

 

[MisterTipsy]

"gravity" in this case is a metric called specific gravity.

In brewing, it's the ratio of density of beer vs. the density of water.

 

[PortlandPatrick]

Check this out for a little info on gravity. http://www.howtobrew.com/section1/chapter3-4.html

 

[harrymanback92]

Sweet. Thanks guys.

 

[TheZymurgist]

You are off base. If not, 1000 gallons of 1.040 beer would have the same amount of sugar as 5 gallons of 1.040 beer.

Yup!! From my saltwater aquarium days, we'd measure specific gravity to test the salinity instead of sugars. The ocean's salinity (depending on location) is around 1.023, and we'd match our aquarium's salinity to the same reading. If the 1.023 meant there were only 23 grams of salt in the ocean, than 23 grams of salt in a 70 gallon aquarium would be way too much.

 

[RobertRGeorge]

I've found Plato (brix) to be easier to understand because it does measure the amount of sugar in solution. 10 Plato (brix) means that the solution is 10 percent sugar and 90 percent water by weight. For example ten grams of sugar plus an amount of water so that both fill a one-liter container equals 10 Plato. If you want to convert from SG to Plato divide by 4. Both scales are usually on a saccharometer.

 

[harrymanback92]

Oh that's cool. I've never understood Plato very well. So I had an OG of 1.049 my number in Plato would be 9.8? So 9.8% of the sample would be sugar?

 

[ktblunden]

Oh that's cool. I've never understood Plato very well. So I had an OG of 1.049 my number in Plato would be 9.8? So 9.8% of the sample would be sugar?

Plato would be about 12.25. Ignore the 1 and the decimal point, 49 divided by 4 equals 12.25.

 

[dinnerstick]

i find it easiest to use a brix-specific gravity conversion chart, easily found online, then the brix number gives you (a very close approximation of) grams of sugar per 100 ml wort

 

[mattpsu27]

i find it easiest to use a brix-specific gravity conversion chart, easily found online, then the brix number gives you (a very close approximation of) grams of sugar per 100 ml wort

Hi I'm new to the site although I've been brewing for quite some time. I have a quick question around dilution and the approximates around the gravity. I had a gravity reading of 1.078 after boil. Making an IPA. I diluted about 5 gal of wort with 32 oz of water but forgot to take another reading. Dumb I know.

Anyone have an idea how much that may have lowered the OG reading?

Thanks!

 

[PortlandPatrick]

Hi I'm new to the site although I've been brewing for quite some time. I have a quick question around dilution and the approximates around the gravity. I had a gravity reading of 1.078 after boil. Making an IPA. I diluted about 5 gal of wort with 32 oz of water but forgot to take another reading. Dumb I know.

Anyone have an idea how much that may have lowered the OG reading?

Thanks!

Your FG works out to about 1.074

78(5)/5.25=74.28

 

[ktblunden]

Your FG works out to about 1.074

78(5)/5.25=74.28

That's a much simpler calculation than the one I posted in the guy's other thread, but we arrived at the same result.

 

[mattpsu27]

Thanks guys!

 

[PortlandPatrick]

That's a much simpler calculation than the one I posted in the guy's other thread, but we arrived at the same result.

I only saw the question in this thread because I was already subscribed. What was the other formula?

 

[mattpsu27]

I only saw the question in this thread because I was already subscribed. What was the other formula?

Originally Posted by ktblunden
640 oz (5 gal) times 1.078 equals 689.92
32 oz times 1.000 equals 32
689.92 plus 32 equals 721.92
721.92 divided by 672 oz equals 1.074