Hey all, I'm pretty inexperienced with homebrewing, and currently have a porter in secondary (5 gallon batch). We extracted 3 vanilla beans in a some bourbon (8oz), and pitched that all into the beer when we moved it to secondary. There seems to still be activity, as the airlock is still bubbling intermittently. Here's my question: My gravity when I moved the beer to secondary had held steady at 1.018 for 4 days. After being in secondary for about a week, we took a gravity reading, and it was 1.020. We double and triple checked, but it definitely seems that the gravity is currently higher than when we transferred. Would the vanilla or bourbon raise the gravity, or should I just chalk this one up to human error?