Unfermentable sugar question

[guscampag]

This may be a stupid question, but...
Does unfermentable sugar such as lactose raise the SG?
I was backsweetening some hard lemonade with lactose and stevia and wanted to raise to about 1.010 or 1.020. When checking with the hydrometer, it did not seem to go up when I added the "sugar".
I had not thought about this before... I hope I didn't make it tooooo sweet!
Thanks.

 

[brazedowl]

I don't know if you've ever compared a bag of the artificial stuff to a bag of sugar. They weigh a lot less because they're less dense. So when you dissolve them they add less mass per unit volume and change the SG less. You may need to backsweeten to taste rather than SG.

 

[DoctorCAD]

SG is only a measure of how thick a fluid is compared to water (1.000). Nothing more.

We use it to check sugar levels and ABV levels, but an SG can be taken on any liquid.

If the lactose or stevia imparts less "thickness" than sugar then SG really doesn't give you the same end result. Never having used either, I don't know what the SG additive of either of those 2 compounds is. A quick Google search shows a 70% lactose solution is SG 1.333, you might be able to interpolate back to 1.02 with some math work.

 

[Honda88]

I would take a small sample and sweeten it too taste, then use that ratio for the whole thing, much easier...

 

[guscampag]

Yeah,
I guess I'll just go by taste from now on. Maybe I'm not as smart as I thought I was!!!

 

[roadymi]

Yeah,
I guess I'll just go by taste from now on. Maybe I'm not as smart as I thought I was!!!

You can still take readings for future reference. Say for example you started at 0.998 and you sweetened to taste and it ended up at say 1.008 and it took 1/2 cup of your chosen sweetener you now know that 1/2 cup raises your sg by .001 for given volume.