[1.12] Adding custom potion recipes using vanilla potions

Alright, so I have some custom potions that I want to be brewed using some custom items in the vanilla brewing stand. So I've figured out how to make custom brewing recipes using BrewingRecipeRegistry.addRecipe, but when I try this:

BrewingRecipeRegistry.addRecipe(PotionUtils.addPotionToItemStack(new ItemStack(Items.POTIONITEM), PotionTypes.AWKWARD), new ItemStack(AMItems.SHOCK_STONE), PotionUtils.addPotionToItemStack(new ItemStack(Items.POTIONITEM), AMPotionTypes.ZAPPED));

the recipe will be brewed but it also will brew no matter what kind of potion is in the brewing stand when the ingredient is present. So I did a bit of research and found a past forum post here that mentioned that the recipes ignore NBT so a custom recipe implementation would need to be created. That sounded like it wouldn't be fun to do, and since the post was from 1.9.4, I was wondering if there was a better way to do this since then. So I then went and found almost what I was looking for:

PotionHelper.addMix(PotionTypes.AWKWARD, AMItems.ITEM_SILVER_SHELL, AMPotionTypes.AMFATIGUE);

This works great for the custom potions I have that use a PotionType, but for various reasons, I have created a bunch of custom potions that are just custom items instead of PotionTypes. I still want them to be brewed using vanilla potions but the end result will be an item that isn't derived from a PotionType. Here's an example of what I want to do:

BrewingRecipeRegistry.addRecipe(PotionUtils.addPotionToItemStack(new ItemStack(Items.POTIONITEM), PotionTypes.AWKWARD), new ItemStack(AMItems.ITEM_HUNGRY_SLIMEBALL_BIG), new ItemStack(AMItems.ITEM_NUTRIENTS));

But of course, this puts me back in the situation where I was before where it won't matter what kind of potion is used in the brewing. So I'm just wondering if there is some nice way I can add this recipe, or will I just have to implement custom recipes?