Logarithmic curve with spiralling cross-section I'm trying to make a logarithmic curve with a rotating cross-section.

I have created a curve object following the instructions at 
How to create this kind of spiral tube?, giving me the curve shown below, which has an elliptical cross-section that increases in size along the length of the curve. 

However, as well as the size of the ellipse increasing along the curve, I would like it to twist, giving a 'corkscrewing' final result that will superficially resemble fusilli pasta.

It seems like this should be a simple thing to do, but I can't see a way to do it.  Can anybody help?
Have you tried the tilt property of the curve's control points?

If you select one or more curve vertex and press Ctrl + T you enter tilt editing mode where you can control the twisting effect of the curve.

Depending on how your curve was built you can control this for one or more vertex at a time.

If you need to make a smooth gradient across a multitude of points you can use Proportional editing O key to affect adjacent vertex. Use Mouse wheel  to adjust the affected radius.