how to improve quality of butter-steamed cavebulb?

[DrSun]

cavebulb quality 10
butter quality 11

water quality 10
cauldron made of 27quality clay
fuel - boards quality 20

and i get butter-steamed cavebulb quality 9

why 9? i have to stats below 10. skills only stealh and melee combat below 10.

is it bug or what i have to raise to get at least 10ql buttersteamed cavebulb?

[DrSun]

and yes. from butter quality 10 it's still ql9 buttersteamed cavebulb
and from butter ql7 it's ql8 buttersteamed cavebulb.

[Potjeh]

Clay cauldron halves water quality.

[DrSun]

oh sh.... thanks.