First, I am using a Sigelei 150w box with a smok TFV4 and mainly the quad coil. I have been playing with mixing my own juices from concentrates (mainly FA brand concentrates) and mainly strawberry. I got hooked on a raspberry ice that a local vape shop had and have been trying to recreate it and found I like the strawberry better than the raspberry. On the batch I made up recently I get a burnt taste after a few drags. If I switch the tank back to the store bought raspberry ice, the taste goes away. I am vaping at 50w/4.4v on the box and the quad coil is rated between 40-140w and is .15ohms. I can't figure out why my homemade batch gives me the burnt taste. i have made other batches in the past and did not have this happen. I am using some different concentrates but keeping the mixes down to around 12%. I started with 30PG/70VG. My thought was that it just wasn't wicking enough so I have been adding PG to thin it out. As I go more to PG it seems better but not much. Any ideas from the experts?