How to learn new potion's formula?

Question

I am currently a player - druid lvl 5 with Nature, Medical and Survival skill proficiencies and I have proficiency with the Herbalism kit - and we had such a discussion with our GM, and we don't have a clear point of view of how crafting potions works. I mean, I know in game 2-3 basic ones (potion of healing, antitoxin for paralyzed poison, potion of climbing). I can "research" new ones by combining ingredients.

How can I learn new potion recipes?

Is this explained in the PHB or DMG? I couldn't find that.

Another solution and question about that: We have an artificier in game, who knows how to create potion of greater healing (Uncommon). Is it possible for him to make a formula for this potion and give me that formula? Thanks to that I could learn this recipe and create that on my own.

There is a high probability, that it is not clearly explained neither in PHB nor in DMG. Maybe someone of you have met with such a problem in yours campaign and can provide a solution. I would be interested in hearing all of them.

The answers in related question may be a guide for basic rules, but it is not referring to more complex potion crafting.

Answer 1

Xanathar's Guide has mechanics for this.

Crafting a magic item, which includes all potions, can be handled via the Downtime Activity rules in Xanathar's Guide to Everything. All of the rules in the Guide are optional, of course, so it's up to your DM if they want to use this system.

In general the process is as follows, and I've emphasized what I think is the primary answer you're looking for:

• Obtain a formula for the potion. There are no specific rules for obtaining potion formulae. Your DM may rule that you need to use the Research downtime activity first to find such a formula, or it may require adventuring or other activities.

• Obtain the exotic materials required for the potion. All magic items invariably require such materials, and finding those materials should happen as part of an adventure. The rules suggest the challenge rating of a creature that must be faced (not necessarily slain) to obtain these ingredients, based on the rarity of the potion.

• Pay for other materials and tools based on the potion's rarity (from 25gp for common potions to 50,000 for a legendary potion).

• Spend time crafting based on the potion's rarity, from half a week for a common potion to half a year for a legendary potion.

• For most potions, proficiency with Arcana is required.

Generally no ability check is required for the crafting itself — once the formula and ingredients are obtained, and the gold and time is spent, success is automatic.

It's important to note that every part of the process of crafting magic potions is totally at the DM's discretion, and they are free to complicate any step as they see fit.

Potions of Healing

There are special rules for crafting potions of healing of all levels (regular, greater, superior, supreme). Any character (including the druid described in the question) who has proficiency with the Herbalism Kit can create these potions just by spending time and money, with no special ingredients or other requirements.