Of course, a premisis

Yesterday my colleague Clutchslip sent me an email with the subject 'Today's new word':

Just reading about an aspiring brewer who decided that what he needed was “of course, a premisis to brew in.”

Of course!

Now Clutchslip didn't want to embarrass the brewer so I won't do any naming and shaming either (feel free to Google, though).

But I can say that 'premisis' isn't that new a word, at least judging by this GrammarBlog post.