1 cup of sugar=.??? SG per gal

[rj_picou]

I'm just a little (actually very) confused about the SG of sugars. I've read that 1/2 cup of sugar will give a SG of .010 per gal. but some recipes I've read, the numbers just don't add up.

can someone please enlighten me with a universal formula

 

[causeimthesquid]

It's just sugar. You could measure it. That way you aren't taking anyone's word for it. Just dissolve a 1/4 cup of sugar in a quart of warm water and use your hydrometer

 

[jensmith]

The fruit or juice adds to the suger amounts. Those are diferent every year. Take your bace sg leavels with those juices. After that, any suger added should rise the sg in a consistant maner.
I second the testing plain suger water to get a standard for suger added. Generaly 1cup suger to one gallen gives an sg of 1.020. (I think!)


Sent from my iPod touch using Home Brew

 

[DoctorCAD]

8 ounces of sugar added to 1.000 water should give you 1.020. I don 't know how much a cup of sugar weighs...8 oz???

 

[Yooper]

8 ounces of sugar added to 1.000 water should give you 1.020. I don 't know how much a cup of sugar weighs...8 oz???

I think it's something like 2.5 cups of sugar per pound, but a small kitchen scale really is crucial for winemaking, They are less than $5, and much more accurate than "cups" as a fine granulated sugar can fit more in a cup than a coarser granulated sugar- but you still need XX ounces, not cups.

 

[rj_picou]

1 cup of sugar weighs 7.05oz...a pound is 2.695 cups.
i got this info off the Domino Sugar sight.

 

[bernardsmith]

I use a rule of thumb that in one gallon , a pound of sugar increases the gravity by .040. A half pound raises the gravity by .020 and 4 oz will raise the gravity by 010. Two oz (or 50 gms) will raise the gravity of one gallon by .005.

 

[FredTheNuke]

I'll probably be able to test this tomorrow. Trying to brew a Westy 12 clone with a target OG of 1.091 - Beersmith says it will require more grain and water than my MLT can hold by a smidge. I intend to adjust the Pre Boil BK reading with corn sugar.

4 oz in one gallon = +0.010 SG change

 

[noallawshe]

SG of sugar = 1cup sugar to 1 gal water is 1.046.!

 

[passedpawn]

SG of sugar = 1cup sugar to 1 gal water is 1.046.!

No.

The SG, or specific gravity, is the density ratio you get with a hydrometer when you add 1 pound of an ingredient to 1 gallon of water.

1 pound of sugar in 1 gallon of water is 1.046. Since a half a cup of sugar only weights about 3.5 oz, 3.5 / 16 * 46 = 10, so the answer to the OP's question ( I think ) should be 1.010.

 

[pricelessbrewing]

No.

The SG, or specific gravity, is the density ratio you get with a hydrometer when you add 1 pound of an ingredient to 1 gallon of water.

1 pound of sugar in 1 gallon of water is 1.046. Since a half a cup of sugar only weights about 3.5 oz, 3.5 / 16 * 46 = 10, so the answer to the OP's question ( I think ) should be 1.010.

Technically, the SG is the density ratio of

1 Gallon of the resultant solution when you add 1 lb of the ingredient to a volume of water slightly less than 1 gallon.

To 1 gallon of water.

The ingredient is going to increase the volume of the solution, and potentially absorb some of it, as grain does.

With a potential PPG of 46, you would need to add 1 lb of sugar to 0.93 gallons of water in order to get a resultant sugar solution of 1.046. If you added 1 lb of sugar to 1 gallon of water, you would get a solution of 1.043. This is the same reason a lot of brewing software calculates conversion efficiency incorrectly.


brewersfriend being the biggest one that attempts it, and gets it wrong. Beersmith does not attempt it, AFAIK.

 

[applescrap]

@passedpawn thanks, excellent.

 

[passedpawn]

Technically, the SG is the density ratio of

1 Gallon of the resultant solution when you add 1 lb of the ingredient to a volume of water slightly less than 1 gallon.

To 1 gallon of water.

The ingredient is going to increase the volume of the solution, and potentially absorb some of it, as grain does.

haha, ok. So, can you answer the OP's question then?

 

[pricelessbrewing]

Granulated sugar is supposed to be 200g per cup, so 0.5 cups ~= 0.220462 lbs (~3.5274 ounces)

Added to 1 gallon of water, you should have a solution of ~1.01006.

Note the two approximations

1) You're measuring by volume, which will vary depending on packing the cup, and how fine the granules are. Weighing the sugar is a much more accurate method of measuring, especially solids.

2) Not sure how trustworthy the 200g per cup estimate is.

Unfortunately, this is not quite a linear formula. If you multiply the sugar by 8 , you do not get 8x the gravity. You get 1.07184, which is 7.14 x the gravity.

 

[noallawshe]

oops i meant 1 pound

 

[Mallerstang]

I'm just a little (actually very) confused about the SG of sugars. I've read that 1/2 cup of sugar will give a SG of .010 per gal. but some recipes I've read, the numbers just don't add up.

can someone please enlighten me with a universal formula

I've been wondering this too, since I like to experiment, and I've just come up with this:

SG = (W+S)/(W+0.625xS)

where W = water in litres
and S = sugar in kg


That's from combining SG = density of solution/density of water

with the formula vf = vi +A/b

where vf is final volume in litres, vi is initial volume in litres, A is grams of sugar, and b is constant 1600 g/litre

which I found here: http://www.brsquared.org/wine/CalcInfo/addcalc.htm

(where it explains that the vf formula is approximate but works well)

I've tested my formula against a couple of solutions I made up, and it is close to my actual SG readings. Also, for 0.93 gallons water and 1 lb sugar it gives 1.04476, whereas someone else here said SG would be 1.046. Difference could be due to rounding at steps in the calculations.

Thoughts anyone?

 

[pricelessbrewing]

I've been wondering this too, since I like to experiment, and I've just come up with this:

SG = (W+S)/(W+0.625xS)

where W = water in litres
and S = sugar in kg


That's from combining SG = density of solution/density of water

with the formula vf = vi +A/b

where vf is final volume in litres, vi is initial volume in litres, A is grams of sugar, and b is constant 1600 g/litre

which I found here: http://www.brsquared.org/wine/CalcInfo/addcalc.htm

(where it explains that the vf formula is approximate but works well)

I've tested my formula against a couple of solutions I made up, and it is close to my actual SG readings. Also, for 0.93 gallons water and 1 lb sugar it gives 1.04476, whereas someone else here said SG would be 1.046. Difference could be due to rounding at steps in the calculations.

Thoughts anyone?

The 0.625 liters per KG of sugar is not always true, it's a non linear volume contribution. I can post the actual formula later if you really want it.

 

[Yooper]

One of the simple mistakes some people make is to add 1 pound of sugar TO 1 gallon of water, while others dissolve the sugar in water to make 1 gallon. They are not "wrong", but will give different results so keep that in mind.

1 pound of sugar doesn't take up much volume, but if you're making a 5 gallon batch of wine and using 2.5 pounds of sugar per gallon, that does make a huge difference in the end.

 

[Mallerstang]

The 0.625 liters per KG of sugar is not always true, it's a non linear volume contribution. I can post the actual formula later if you really want it.

Yes please - that would be great! The site where I found the formula did say it's not exact but is fairly close. They had 1600 g/litre as an approximate figure, and the 0.625 litres/kg is the reciprocal of that.

I do find it handy for planning what multiples to make of the recipes I find.

 

[Mallerstang]

The 0.625 liters per KG of sugar is not always true, it's a non linear volume contribution. I can post the actual formula later if you really want it.

Also, how is it even possible to "spend too much time on beer math?"