After Taste is a 1.15.2 Forge Mod primarily designed for Mod Pack makers. You will either need to make a Datapack or use something like The Loader.
Using After Taste you can assign potion effects to items, primarily food items but anything that fires off the LivingEntityUseItemEvent.Finish event works, via Item Tags. Since it is Tag based it affects all instances of the tagged Item. Effects are treated as recipes and are as such synchronized between the server and client upon connection meaning you can add custom effects for your server.
You can for example make items with the tag "minecraft:fishes" give you Water Breathing for 5 minutes.
To do that, you would add a recipe like follows
{
"type": "aftertaste:food_effect",
"itemTag": "minecraft:fishes",
"effects": {
"name": "minecraft:water_breathing",
"duration": 6000
} }
'effects' may be either a JSON Array or a JSON Object, Additionally, the 'effects' entries support additional values to further specify the effect:
"amp": 0 #DEFAULT 0
"ambient": false #DEFAULT false
"particles": true #DEFAULT true
