Actually, "Why is that?", would be the correct grammatical form.
"John Barleycorn was a hero bold,
Of noble enterprise;
For if you do but taste his blood,
‘Twill make your courage rise.
‘Twill make a man forget his woe;
‘Twill heighten all his joy;
‘Twill make the widow’s heart to sing,
Tho’ the tear were in her eye.
Then let us toast John Barleycorn,
Each man a glass in hand;
And may his great posterity
Ne’er fail in old Scotland!"
An extract from "John Barleycorn", by Robert Burns.
A link to beer poems.http://brookstonbeerbulletin.com/top-ten-tuesday-top-10-beer-poems/