Salumi and charcuterie artisans recognize that consistency is key to keeping high-end purveyors and chefs as customers. But by definition, these raw, fermented, cured sausages are living foods and evolve over the aging process, which is key to their flavor development. There are some upfront quality reassurances that can be made prior to encasement. 

Glucono-delta-lactone (GDL) can be used instead of — or sometimes with — lactic acid starter cultures to decrease pH, which in turn coagulates proteins. This lowering of acidity is also an important safety step, as it creates a hostile environment for spoilage and pathogenic microorganisms to grow.

GDL, a generally recognized as safe (GRAS) ingredient, is particularly useful in medium- and fast-fermented sausages, as increasing acidity quickly is paramount for safety. In slow-fermented sausages dried for a much longer time, lowering water activity upfront is more important for inhibiting undesirable microbial growth.

While it may sound like a laboratory manufactured chemical, GDL is a natural acidulant produced by microbial fermentation of glucose. It is soluble in water and completely metabolized by the human body.

GDL is considered a slow-release acid, as in the presence of water, it slowly releases gluconic acid to lower the pH of the meat system. This, however, is faster than many encapsulated acids used in sausage making, and much faster than starter cultures alone. Thus, it is paramount that the meat get encased quickly to avoid stability issues. The benefit to using GDL is the assurance of proper acid development for safety, texture and flavor development.

A good rule of thumb is that for every 0.1 percent of GDL in a sausage matrix, pH is lowered by about 0.1. At a usage rate of 1 percent, some bitter and sour notes may start to come through.