It's impossible to describe but it immediately signifies that what you are drinking has not been successfully commercially produced so you are better staying in blissful ignorance of the experience!
Yea as a coverall for "twang".
But maybe more descriptive versions of peoples personal "twang"
What twang are you suffering from
I have suffered from a medicinal, antiseptic, germolene reek "twang" cubed. Others might describe it as plastic, vinyl, hospital, Iodine, Bromine. An organoleptic analyst might say Chlorophenol. I have only ever found this on all grain brew never a kit, it rendered the brews undrinkable for me.
Can be caused by the presence of Chlorine or Chloramines in your brewing liquor. Contamination from sanitising chemicals.
Since suffering from it I prepare the liquor the day before brewday filling Hot Liquor Kettle and Mash Tun with appropriate volumes as vigorously as possible and adding 1/2 a crushed camden tablet to each. The vigorous filling, over nightstand & the action of sodium metabisulphite seem to have done the trick in removing chlorine so it can't react with the polyphenols extracted from the grain during the mash.
The "twang" I mostly associate with poor homebrew is a yeasty, fruity, estery aroma a combination of the poor yeasts provided with some kits and overenthusiastic unrestrained hot fermentation.
https://www.belgiansmaak.com/off-flavours-in-beer-off-flavours/
https://www.winning-homebrew.com/off-flavors.html
https://www.nottingham.ac.uk/biosci...oduction-to-beer-flavour-saf-21-july-2017.pdf