GR translation: mulled with the hammers of Hell

[Mike Jing]

P193.27-35
The Ballad Of Tantivy Mucker-Maffick
Oh Italian gin is a mother’s curse,
And the beer of France is septic,
Drinking Bourbon in Spain is the lonely domain
Of the saint and the epileptic.
White lightning has fueled up many a hearse
In the mountains where ridge-runners dwell—
It’s a brew begot in a poison pot,
And mulled with the hammers of Hell!

What does "mull" mean here?  I found this:

to heat, sweeten, and flavor with spices for drinking, as ale or wine.

Is that it?