Clean label mold inhibitors are the alternative to chemical preservatives that help inhibit mold growth or prolong the shelf life.

Clean Label Mold Inhibitors

Also known as Natural Mold Inhibitors

What are Clean Label Mold Inhibitors?

Clean label mold inhibitors are natural preservatives that help control mold growth and prolong the shelf life of food. Products like whole wheat, multigrain and artisan bread are good uses for these ingredients.

These ingredients provide bakers with a wide range of benefits. Although, they may present unique challenges.1 Examples include:

  • Vinegar
  • Raisin and prune juice concentrates
  • Fermented/cultured flour
  • Starch
  • Whey


Clean label mold inhibitors in bakery applications have become a core subject in the development of new products. High-speed bakers are starting to replace chemical preservatives, like calcium propionate and sorbates, with natural mold inhibitors.


There are two main clean label mold inhibitor categories, based on what they do. First is pH reduction in dough or batter, and then disrupting mold cellular membranes and processes.2

Category 1: pH reduction:2,3,4,5

  • Vinegar
  • Prune/plum  juice concentrate (PJC)
  • Raisin juice concentrate
  • Culture whey products
  • Cultured flour

Category 2: Cell disruption:2,6

  • Cinnamon
  • Cloves (Syzygium aromaticum)
  • Natamycin

Commercial production

  • Vinegar: produced through the fermentation of carbon sources using food-grade microorganisms, like acetic bacteria.
  • Fruit juice concentrates: prepared by a series of soaking or washing steps of raisins, plums or prunes in water. Then, the liquid containing leached organic acids is evaporated under vacuum to a 70° Brix syrup.
  • Cultured whey products: obtained by fermenting pasteurized sweet whey, with a culture of food-grade lactic acid bacteria (LAB).
  • Cultured wheat flour/starch: similar to cultured whey products.
  • Cinnamon, cloves: natural spices 
  • Natamycin: produced through fermentation of carbon sources, using the food-grade microorganism Streptomyces natalensis.


Category 1:  pH reduction1,2,3,4

Relevant aspects / benefits Amount used (baker’s %) Associated challenges


Active component: Acetic acid

  • Vinegar is a dilute solution of acetic acid in water.
  • Strength of vinegar is measured in “grains.” 1 grain is equal to 0.1% of acetic acid.
  • Commercial bakers use 100-grain or 200 grain vinegar (10% or 20% acetic acid, resp.)
  • Does not contribute to color.
  • pH: 2.3–3.4 (100–300-grain)
0.5–2.0% (50-grain), or

0.25–1.0% (100-grain)

  • Because it's a weak acid, it dissociates poorly in aqueous media. So, this limits its effectiveness in...

To access the rest of this page, you must be a member of the American Society of Baking.