Not sure how you brewed it but, this is how I make mine.
Fill a glass bottle with 1/2 coffee grounds and 1/2 pg. Nuke for 10 seconds. PG will be absorbed by the coffee so now add more PG to fill the bottle. Let solution sit in glass bottle inside of a coffee cup filled with hot tap water for about 20 minutes. Remove. Use a paper coffee filter attached to the inside side of a glass cup or jar with a chip clip or similar. Pour mixture into the paper filter and let it strain for a few hours. You now have a good coffee flavoring to use in your DIY mixes.
I hope that helped and good luck!