How does one get a smooth paste with zinc ricinoleate . When heated with butters and oils it gets clumpy . I need to make a balm?
Achieving a smooth paste with zinc ricinoleate in a balm formulation is one of the bigger formulation challenges due to its tendency to clump when mixed directly with butters and oils. To avoid this, start by pre-dispersing zinc ricinoleate in a small amount of a compatible carrier oil, such as isopropyl myristate or caprylic/capric triglycerides. This step ensures it distributes more evenly when added to the main batch.
When heating your butters and oils, keep the temperature gentle, just high enough to melt the butters but not so hot as to cause the zinc ricinoleate to clump. Temperatures around 75°C to 85°C are typically sufficient, though adjustments may be necessary based on your specific ingredients’ melting points.
Add the pre-mixed zinc ricinoleate to the melted butters and oils slowly and steadily while continuously stirring. This gradual integration helps prevent clumping by allowing the zinc ricinoleate time to blend smoothly into the mixture. Consider using a high-shear mixer to ensure a smooth consistency, breaking up any clumps that might form. If such equipment isn’t available, vigorous whisking can also be effective, though requires more effort – use elbow grease (expression may not be understand outside UK).
Incorporating an emulsifier or dispersant, such as lecithin or a polyglyceryl ester, can further stabilise and disperse the zinc ricinoleate within the balm. After achieving a uniform mixture, test the texture. If clumps are present, gently reheat and mix again using high-shear mixing. It may take a few attempts to perfect the method.
Finally, allow the mixture to cool slowly at room temperature. Rapid cooling could cause the zinc ricinoleate to harden unevenly, leading to a grainy texture.
This has probably made it sound a bit easier than it is. Allow plenty of time for this particular problem.