Emily Confusing Dickinson

Ok, normally I don't understand the poems we read until we have gone over them, but seriously, what is "I Taste a Liquor Never Brewed" about? I mean, I normally get a crude idea of a poem (as seen in my other blog posts), but I honestly have no clue what this poem could mean. Is it actually for once a poem that literally means what she is saying? "I taste a liquor never brewed, from Tankards scooped in Pearl". Is tankards and pearl capitalized for a specific reason? Or, is it just there to make us overthink this poem? And this poem also goes as far to mentioning angels. "Till Seraphs swing their snowy Hats, and Saints, to windows run". This poem has gone from scooping alcohol with pearl, to inebriation off of air, to angels. I need help with this poem more than any we have read so far.