I have made alcohol- based freezer tinctures, that turned out great! Some people like to "toast" the weed, before beginning the tincture process (converts THCA to THC, they say - but there are good medical reasons to believe that THCA is a good thing and also adds to the high.

So, I would do whichever you prefer, since both ways work. I've made tinctures with and without the "toasting". Strength seemed the same, but the green one didn't have that cooked-weed taste.

Good Luck!