Lower difficulty of cream recipes to 3

[Cimanyd0]

Summary

None

Purpose of change

With food handling 3-4, and the book Things to Do with Milk, part of the process of turning raw milk into raw butter is visible, but part is not, because some of it is in the book at level 3 but some is autolearn at level 5. This does not fit the description "Whatever you want to do with milk, you will probably find it in this book."

Turning raw milk into heavy cream and buttermilk (through two recipes and waiting a while) is difficulty 5, autolearn.
Turning heavy cream into raw butter (two different ways) is difficulty 5, learned from dairy_book at 3.

Describe the solution

Make the cream recipes book-only as well.
Also make whipped cream book-only, because the previous change means there's no way to get heavy cream without the book.

Edit: Lower the recipe difficulty of milk_cream_jar (rising cream jar) and milk_cream (heavy cream) from 5 to 3.

Describe alternatives you've considered

Edit: The first version of this PR put the cream recipes into the milk book at level 3, leaving the difficulty at 5, but that meant pouring milk into a jar (at food handling 3) would often destroy the milk or the jar.

Should any of this still be autolearn, in addition to being in the book?
Should the difficulty of some steps be lowered to match the new requirement? I don't know what all the steps involve. If one of them really is just pouring raw milk into a big jar and waiting a while, that shouldn't be able to fail. Should it take a whole 5 minutes to pour it in?

Testing

Have not tested yet
Edit: Can't craft rising cream jar or heavy cream at food-handling 2. Can at 3. Failures are still possible at 3, but less likely. I'll assume you have a small chance to knock your jar off a counter, breaking it and spilling out the liquid(s), which then disappear into thin air along with the broken glass.

Additional context

@Maleclypse added both the butter recipes (#34854) and the milk book (#37263), so maybe they have some input? Or anyone else who knows about making butter.

Edit: The current PR does not affect whipped cream or gate anything extra behind books.

[Maleclypse]

This looks good. I can’t see what’s causing the error from my phone so I kicked the test.

[PatrikLundell]

I'd expect almost everyone to know how to make whipped cream, so that should definitely be auto learned at a very low level. Trouble getting the ingredients shouldn't affect the ability to use the ingredients once present.

Unless there is something really tricky with these recipes, I think they should still be auto learned once reaching a sufficiently high skill (until a system where you can experiment to develop (a.k.a. "unlock") recipes is developed). I'm not a fan of gating recipes behind a specific book unless the recipe is of a nature that makes it almost impossible to find out yourself (obviously not completely impossible, since someone came up with it originally).

[Cimanyd0]

I changed the PR to only lower the difficulty of the cream recipes, leaving them autolearn. This still makes all the butter steps show up at level 3 (if you have the book). It doesn't make you destroy lots of milk and jars failing to pour milk into a jar. It lets survivors figure out something that would happen by accident the first time they let raw milk sit around for a while, if I understand correctly.