Using Dextrose in Beer?

I see some recipies that call for dextrose. I tried to do some research but not quite narrowed what it is used for down.

Is Dextrose (Corn Sugar right?) used to "dry" beers out? E.g. it should ferment completly, leaving all alcohol and no resisidual malt/sugars which would mean body?

Thus if I want a "ligher" body beer, would I add dextrose to the boiling wort? If so, any techniques to be aware of? Is there any good practice on how much to use?

I am trying to thin out the body/maltyness of an IPA, and was thinking of adding a very small amount (.25lbs). Am I on the right track?

yup, youre right. One tip is to add the dextrose at the end of the boil (last five minutes or so), so as to not mess with your hop utilization/IBU calculation during the boil. Or, you could boil up a dextrose/water mix, and add to your primary fermenter at high krausen (this is my preferred method). I like to add atleast half a pound of dextrose to my light bodied IPAs, and ive used up to 1.5 pounds (for a 5 gallon batch) with good results.

Great advice, thanks!

When adding at high krausen, do you just take into account the additional total gravity (and total volume as well - 1.046 right?) as to not throw off your recipe?

E.g. I guess if I'm adding .25 gallons of water with 1/2 lbs of dextrose, I would just subtract that much total gravity and try and finish my boil at .25 gallons short of intended?

Cheers

Sucrose is 46 ppg, use 37 for dextrose.

or if you use brewing software, you can put the sugar into the recipe like it was boiled but add it during high krausen...easy math