Custom Recipes in Minecraft 1.12, for those of you that don't know adding custom recipes in Minecraft 1.12 is actually pretty easy. First off you're gonna want a profile for just this, so that when you run the game it doesn't automatically update all your recipes out of minecraft.

(Now technically this is a mod, but it works with any version of Minecraft that has a recipe folder under assets in the minecraft.jar.)

To make this custom profile your work your gonna need to copy paste a currently installed minecraft version, which are stored in the .minecraft/versions folder. From here copy paste the folder named 1.12 to somewhere safe.

This is where it gets tricky, from here you want to open the 1.12.json in the folder you copied and copy all the text, from there go here, http://ift.tt/mVvXH2 and paste all of the text in. Then in the top left, press format. It should look much more readable now.

Now you want to remove everything between “assets”: “1.12” and “id”: “1.12” beginning with “downloads”: { and press format again to make the json work. Also change the 1.12 in the id to the name of your custom profile. Link to image describing this better http://ift.tt/2s8oywo

Now assuming that all worked, change the name of the folder, the jar file and the json file that you copied from the versions folder, make sure you have them all as the exact same name, or Minecraft won't find the version. Once you have done that, copy the folder with the changed names and altered json file back over to the versions folder.

Test that the game runs and that the jar file and json file don't update. Personally I look at the time stamp. If they don't update you are good.

From here use this website to make your custom recipes. http://ift.tt/2t5ZzHs This website outputs json files, that you will want to rename in all lowercase letters and using underscore for spaces, like this cobblestone_stairs, once you have made your custom recipes, all you have to do is add these json files to the jar file. This is a simple process, and unlike other mods you don't need to delete the META-INF folder.

Open the jar with any zip file reader, I prefer 7zip for this as it's free, but use whatever you have, then navigate to the assets/minecraft/recipes from here you should see a collection of json files, add your own recipes to these, and Minecraft will read them, and that's it. Enjoy your custom recipes without waiting for 1.13.

Now if you get this odd bug where some things are crafting that's caused by a non working custom recipe, I have no idea what causes it, but it does happen. I assume it's probably a bug, and that it will eventually get fixed.