short answer: usually, yes.
long answer: it takes ten seconds and fixes two tiny problems at once.
a paper filter can carry a papery taste. some filters have more of it than others. rinsing the filter with hot water washes away a lot of that flavor before the coffee goes in.
it also heats the brewer and the cup.
that matters because a cold dripper steals heat from the brew. coffee extraction likes a steady temperature. starting with warm equipment gives you one less thing to fight.
here is the whole move.
put the paper filter in the brewer. pour hot water around the filter until it is fully wet. let the water run through. then throw that rinse water away.
please throw it away.
pouring coffee on top of the rinse water is a very efficient way to make weak, confusing coffee.
now add the ground coffee and brew.
if you want to see whether rinsing matters with your filters, do a weird little test. rinse one filter into a clean cup. let the water cool. taste it next to plain water.
if the rinse water tastes like cardboard, you have your answer.
some paper filters are very clean and the difference may be small. that is fine. rinsing is still useful for preheating the brewer and helping the filter sit flat against it.
tl;dr: rinse the filter with hot water, dump that water, then add coffee. it can reduce paper flavor and preheat your setup.
or skip the experiment and let us make your next cup at couplet.
coupletcoffee.com / @couplet
gefen