The Gourmet Specialists - Fig Sticky Balsamic Vinegar

I have bought two bottles of this now thinking I did something wrong or left the lid open a little but both bottles have hardened at the bottom at least a 3rd of the bottle !? I can’t use half of the product , I do love the flavour but I won’t purchase any more now that I know it sets and you can’t do anything to fix it. I store in the cupboard I never refrigerate I just don’t know how to use this without not happening