Flip chip fluxes are like wine in a couple ways, and very different in others…
1) Flip chip fluxes and wines are carefully manufactured and tested, although flip chip fluxes should not sit around and become ‘aged’.
2) Flip chip fluxes and wines come in various viscosities, while exact viscosity consistence is only critical for flip chip fluxes.
And finally,
3) You don’t pour more wine than you’ll drink at one sitting, and you shouldn’t pour more flip chip flux in your spray tank than you’ll use in one shift.