On 11/13/2017 at 10:35 AM, occam's razor said:
My issue (apologies for not being succinct but I didn't want to leave anything out) is that I went to try some yesterday which has been sitting for about a month now and it has a sediment which looks like mud in wine and some flecks of "stuff" in it.
My falernum does something similar. In my case I know it's not sugar crystallizing and I don't believe it's mold either (I've seen mold and it looks very different).
The sediment stuff I suspect is due to flocculation - fine particles (from the solid ingredients used in the recipe) that were not completely filtered out and that, over time, clump together forming larger particles which eventually fall to the bottom of the bottle via sedimentation. If that's the case, then it's still safe to use. Just be careful to pour it slowly so the sediment doesn't transfer into your drink.