I think there is a common misunderstanding of the relationship between state and federal law. I remember at one time Idaho defined wine in a way that spirits products of less than 24% ABV were wines within the state. That cnflict caused no problems. The state went its way; the federal government did too. Or at least I think I recall this. It has been some time. However, if I'm correct, it would be illustrative of the fact that although it is true that you must obey both federal and state law, nothing compels the two governments to impose the same requirements or define terms in the same way. The question, "What is brandy for the purposes of the FAA Act?" will determine how you must label any product you introduce into interstate or foreign commerce, but that does not mean that, despite the federal labeling, some state, somewhere, might hold it to be brandy for the purposes of some state law relating to some requirement, such as allowing sales of spirits distilled from honey wine, which are a specialty item under federal law, but could come under the rubric of brandy for the purposes of some state law related to retail sales by craft distillers.
I have no idea what California requires or prohibits, but when looking for a fit between state and federal law, remember that definitions can differ. The most common one divergence, I think, may be in the definition of "import," which on the federal level means to add to the mass of goods belonging to the United States, which may not be exact, but which is close, whereas the states generally use the term to mean bringing the goods into the state from either outside of the country or from another state.
I'll add one more statement, because something I said above is not absolutely correct. You must obey both federal and state law if you can obey both. But where there is a direct and positive conflict between what the state requires and what the federal government requires, the states prevail. That rule has run afoul of the commerce clause in the past few years, but I think it holds well until the courts decide otherwise. That said, I'm not an attorney, this is not meant to be legal advice, if you find a situation like that (unlikely) consult your attorney and let the attorney advise you about which law you should violate in order to obey the other. Again, this is not going to happen but rarely, if ever, and I l know of no example of where it might even exist.