A Bit of Food Science
Salt. Water flows through food cell membranes towards greater concentrations of dissolved particles. This chemical process is known as osmosis. When we place food in salty water, we “dry” it in liquid. Because salt concentration is higher outside food than inside, food loses its juices until the balance between inside and outside is reached. Plant cells “dry out” as much as 50%, reducing the water activity.
Carbon dioxide is soluble in water and can travel through food cell membranes. Since fruit and vegetables have high water content, they can be carbonated. (Cucumbers have the highest water content of any solid food at 97 percent!)
Carbon dioxide + salt. Adding salt to carbonated water gives the carbon dioxide gas more surface area to form bubbles. Salt accelerates the process of de-carbonation because the more bubbles are formed, the easier it is for the gas to escape. What happens if we fill a jar with cucumbers and salted carbonated water to the top and seal it? There is nowhere for CO2 to escape but inside cucumbers. The combination of carbon dioxide and salt makes the water more active and speeds up processes in the jar.
The Taste of Fizziness. Many Russian-speaking food bloggers agree this recipe makes cucumbers taste similar to malossol ones. Why, if no acidic agents are added? “In later 2009, a team of neuroscientists […] showed that sour-sensing cells [in our taste buds] are the ones that respond to carbonation. […] the sensation begins when an enzyme on the tongue's surface converts carbon dioxide into ions of bicarbonate and hydrogen. The hydrogen ions then trigger the taste bud receptors, which report a sour taste to the brain.” (Modernist Cuisine, V.2, page 465)
