Stiff vs liquid levain

Greetings!

I'm reading Bread by Jeffrey Hammelman; in part, the chapter on levain. I already have a very strong starter that is more stiff. My question: can I use a stiff levain in hammelman's recipes instead of a liquid?

I am anxious to get started on the sourdough recipes, but want to be sure before I begin using my stiff starter rather than Hammelman's liquid levain. I don't have a preference, but just want to apply the right principles.

Any ideas?

Thanks,

Jeff