Leucidal® Liquid SF Preservative * 100% Pure Leucidal® Liquid SF * Natural Preservative. * Authorized Retailed For Leucidal® Liquid SF Product. Leucidal® Liquid is a natural preservative from Active Micro Technologies combining the current trends for alternative preservative systems and peptide technology. Derived from radishes fermented with Leuconostoc kimchii, a lactic acid bacteria that has traditionally been used to make kimchi, this product consists of an isolated peptide that is secreted from the bacteria during the fermentation process that has been shown to have antimicrobial benefits. Leucidal® Liquid is accepted by ECOcert as an ingredient in certified organic cosmetics.