What's mandatory about the Cauldron?? If you totally ignore it you're not benefiting from the Weekly Witch points, but that's the case for most things. Here's a replica of a post in the
US forum.
So Simple  Maybe Too Simple
This post outlines a reliable procedure for using your
Weekly Allotment of Witch Points and
JUST the Brewery Widget. There are no spreadsheets nor fancy calculations. It works the same regardless of the Weekly Diamond Ingredients and how many Diplomas you might have.
 Fewer than 573 Witch Points (or if everything sucks)
 Add a single nondiamond ingredient. You'll have a 20% chance of getting something that's pretty useless
 Press Brew and use the rest of your Witch Points for Studying (permanent buffs for) the various Effects
 OR Note which Effect is the best
 Backout that Ingredient and then look at each of the other 7 nondiamond Ingredients, in turn
 Pick the "best but not very good" Ingredient/Effect and Brew it
 At Least 573 Witch Points
 Add one unit of EACH of the nondiamond ingredients, You'll have a 57% chance of getting something that's pretty useless
 Press Brew and use the rest of your Witch Points for Studying
 OR Add and immediately Backout each of the 4 Weekly Diamond Ingredients, in turn, and note which one yields the most desirable Success Rates
 Add 8 of that Ingredient (200 Diamonds) then Brew the mixture for an 80% chance of getting a buff.
 The best of the buffs should have a 20% or higher chance of being selected, and part of the time you'll get two 20% chances
 At Least 2175 Witch Points
 Add two units of EACH of the nondiamond ingredients, You'll have a 80% chance of getting something that's pretty useless
 Press Brew and use the rest of your Witch Points for Studying
 OR Add and immediately Backout each of the 4 Weekly Diamond Ingredients, in turn, and note which one yields the most desirable Success Rates
 Add 9 of that Ingredient (225 Diamonds) then Brew the mixture for a 100% chance of getting a fairly useful buff.
 The best of the buffs should have a 25% or higher chance of being selected, and part of the time you'll get two 25% chances
You'll hear about all sorts of "great" recipes, but very few of them are useful regardless of the Weekly Diamonds, and most of them will fall apart when you add more Diplomas.
If you want to thread the needle, you can always use the current Google Sheets Solver from
Katwick Cauldrons > Production
or the incremental spreadsheet that
Silly Bubbles has developed.
This is NOT a good week for the Brewery.
The best we can do, using the So Simple procedure, is a paltry:
* 20% for 11_SM
* 16% for 19_A1
* 12% for 05_T2
* 10% for 09_GS 
The Solver doesn't do much better, and it's twice as expensive.
The best that the Solver can do, for a Low Cost Modest Success recipe with the same four Effects flagged, is:
* 20% for 11_SM
* 18% for 19_A1
* 11% for 15_S3
* 11% for 09_OR 
But, just to keep the experts humble, the mediocre performance of the Manual and Low Cost, Modest Success recipes is turned on it's head this week. The Expensive, High Performance Solver recipe is actually CHEAPER than the Low Cost approaches this week. For 200 fewer Witch Points but 100 more Diamonds, the High Cost Solver option came up with:
* 30% for 11_SM
* 30% for 19_A1
* 13% for 05_T2
We'll see how it goes next week.  _____________________________________________________________________
