Yeast starter

Not ideal, but I think it should be okay. 100% table sugar would be a bad idea.
BTW, DME and most ingredients ought to be weighed, not measured by volume.

 

Don't do it. You'll acclimate the yeast to sucrose over dextrose and make them lazy. Just use the DME you have and slightly reduce the water to keep the same gravity.

 

10ml's to each gram of DME, ie 1000 ml of water and 100grams of DME will get you close to 1.040.

 

You can use grain. I usually grind up 18 oz of base malt for a one gallon starter. Mash it for 30 min., boil for 15. Works well.

 

1) First, his starter wort would still be mostly not sucrose. And the predominant sugar would still be maltose.
2) Second, glucose is easier for yeast to use than dextrose. I don't know why you'd be worried about them becoming too lazy to use dextrose. Perhaps you meant maltose. In that case, see #1.

 

glucose is dextrose. did you mean sucrose? too many -oses in this post

 

Goya Malta is easily available substituted, but bee aware of it's dark color.

 

Dangit. Yes, sucrose. Glucose (dextrose) easier to use than sucrose. Therefore, why would the yeast stop using dextrose.