Hard to know for certain without how much of what you used and for how long. Cauliflower, like broccoli, needs a heap of stuff and time to get through the "woodiness" (? if that's the right term? It's a tough vegetable). One of the reasons I often cook with frozen broccoli instead of fresh is that the thawing makes it more likely to latch on to whatever I've tossed it in.
Also, along with Mike's idea of roasting it, you might also blanch it, or give it a very quick stir fry or nuke. Just a minute or so to take the edge off it's rawness might help it grab the brine more.