Gehärtetes Palmstearin — Frequently Asked Questions

Hydrogenated palm stearin is a triglyceride: saturated fatty acids still bound to glycerol, with an acid value below about 1 mg KOH/g. Stearic acid is the free fatty acid obtained after splitting and distilling a fat, with an acid value of over 200. Stearic acid reacts directly with alkalis and metal oxides, while the stearin has to be split or saponified first. Choose the stearin as a feedstock and stearic acid where the free acid is the functional ingredient.

The iodine value measures unsaturation. With 0.5 maximum, the fatty acids released by splitting are already saturated, so the plant does not need to hydrogenate them afterwards. That avoids the hydrogen, catalyst and equipment a hardening step needs, and it gives an acid with better colour and odour stability. An ordinary palm stearin, at an iodine value of roughly 30–45, would give a softer, less stable acid that needs further treatment.

A palmitic-rich saturated acid. The material typically contains about 55–62% C16 and 33–45% C18, and hydrogenation does not change chain length, so the split acid has roughly the same proportions. That suits applications that take a C16-rich blend. If you need a stearic acid with a high C18 content, such as for high-melting or specific crystallisation behaviour, start from a feedstock richer in C18 or fractionate the acid after splitting.

Yes, usually as part of a blend. Its high melting point and hardness help pillar and moulded candles keep their shape, and it adds opacity. On its own it is brittle and can crack or bloom, so candle makers normally combine it with other waxes and adjust the wick. Burn-test every new blend, because wick size, fragrance load and the container affect performance as much as the fat itself.

Full hydrogenation saturates almost all double bonds, and trans fatty acids can only exist where a double bond remains. With an iodine value of 0.5 or less, very little unsaturated material, trans or otherwise, is left. Partially hydrogenated fats are different: they can contain significant trans fatty acids. If trans content matters for your application or market, ask for a gas chromatography result on the lot.

Store bags closed in a cool, dry area away from strong odours, which fats can absorb. The flakes are chemically stable because they are saturated, but heat can make them cake. When melting, use clean stainless steel equipment and avoid holding the fat far above its melting point for long periods, which darkens it. For molten storage, a nitrogen blanket helps protect the colour.