Exp amount based on + of cauldron.
 

Anyone know the algorithm used in determining the amount of exp gained from a successful alch based on the + of the cauldron?

I've gotten close, but with larger exp recipes the figures are way off.

If they're lower than expected, it could be because you can never gain more exp from a single action than half of what you need to get to the next level.

Interesting. Knowing that I rechecked my numbers with a large amount of exp needed to gain a new level.

And here are the figures that I have so far:
Exp from Water of the Wise (Figures gotten from recording current exp before and after alchemy)
Cauldron +0: 403
Cauldron +1: 600
Cauldron +2: 891
Cauldron +3: 1202

That's for a full output alch. (7 waters of the wise)
What I've figured so far on the algorithm::
exp = exp * 1.5 and this gets calculated the amount of times the + of the cauldron is.
For instance.
exp = 403 (+0 cauldron)
exp = 403 * 1.5 = 604.5 (+1 cauldron)
exp = 604.5 * 1.5 = 906.75 (+2 cauldron)
exp = 906.75 * 1.5 = 1360.125 (+3 cauldron)

This algorithm looks good until it gets into the higher +'s.
Subsituting 1.5 for 1.49 or 1.48 makes it a little better. But still not on the dot.

Maybe the + cauldrons calculate your exp as though you were some number of levels lower (but not subject to the half rule). What mental level were you at for the tests?

Actually, I think I may have figured it out. It seems to be based on the percentage of a full value. You get 100 percent with a +3, but the percentage decreases as the cauldron decreases.
Here are my values to back up this theory.
Recipe: Balm of First Aid
Cauldron +0: 244 | 33 percent
Cauldron +1: 364 | 50 percent
Cauldron +2: 516 | 73 percent
Cauldron +3 700 | 100 percent

Recipe: Philosophical Phosphorous
Cauldron +0: 403 | 33 percent
Cauldron +1: 610 | 50 percent
Cauldron +2: 881 | 73 percent
Cauldron +3 1202 | 100 percent

These percentages are approximate. As they seems to range +- a point or two. This variation may be based on other stats/levels.

The exp you get from monsters is calculated by baseexp * (monsterlevel / yourlevel). Alchemy might be calculated in a similar way, which is what leads me to think that + cauldrons might operate by affecting the level variable, since it's unlikely that they multiply the exp by "weird" values like 1.488. It would also explain why there seem to be increasing marginal returns as the + of a cauldron increases.

I'll have to figure a way to test that theory.