Does fermenting seeds and dissolving them in milk, or other liquids, render the drink unlawful (haram) and subject to the ruling on intoxicants (khamr)?

The prohibition is related to intoxication. If the drink in which the seeds were dissolved usually intoxicates, then it is forbidden to drink it; otherwise, it is not. For every intoxicant is Khamr, and every intoxicant is forbidden, and both the little and the much of that whose genus intoxicates are forbidden.