In the 1940s and 1950s, the demand for sweetened lambic continued to grow. “After World War II, consumer tastes became sweeter with the success of cola and soft drinks, and the big brewers in particular played to this trend by bringing so-called ‘capsulekensgeuze’ to the market. “<ref name=“GeuzeKriek”>Jef Van den Steen, [[Books#Geuze & Kriek: The Secret of Lambic Beer|Geuze & Kriek: The Secret of Lambic Beer]], 2012</ref> Belle Vue and other lambic brewers began the process of using pasteurization to prevent bottle conditioning and potential bottle explosions as a result of the residual sugars being left in the beers. Filtration also removed many of the bugs and created a cleaner beverage suited for the soda drinker market.
Sweetened lambic was primarily the result of blending young lambic or other top fermenting beers that contained significant residual sweetness with more tart, aged lambic. As time progressed and fruit lambic became popular in the 1980’s, fruit juices were used to further sweeten lambic (as seen in the De Troch fruit lambics). This was done both to satisfy the market for a sweetened product and because of a shortage of fruit. Lindemans, for example, began sweetening in 1972-1973 because of a shortage of Schaeerbeekse Cherries<ref name=“GeuzeKriek”>Jef Van den Steen, [[Books#Geuze & Kriek: The Secret of Lambic Beer|Geuze & Kriek: The Secret of Lambic Beer]], 2012</ref>. Currently, fruit juice sweetened, pasteurized beverages dominate lambic sales. Some lambic are even sweetened with Aspartame or Saccharin<ref name="Oxford">Garrett Oliver, [http://www.amazon.com/Oxford-Companion-Beer-Garrett-Oliver/dp/0195367138 The Oxford Companion to Beer], 2011</ref>, though it is unclear which breweries or beers use this technique listing 'sugar substitute' as it is not listed an ingredient on the ingredient liststheir beer labels.
Significant confusion over traditional (fondgeuze) and sweetened lambic (capsulekensgeuze) products ensued. The contrast among the beer styles was squeezing out traditional lambic. While sweetening has played a significant role in the history and success of lambic throughout the years, the purists continued to fight to protect traditional lambic. Jean-Paul Van Roy is quoted in [[Books#Wild_Brews:_Culture_and_Craftsmanship_in_the_Belgian_Tradition|''Wild Brews: Culture and Craftsmanship in the Belgian Tradition'']] as saying “The sweet lambic, the sweet fruit beer, and the sweet gueuze don’t exist. It’s impossible. If it is very sweet there are three possibilities: It is not a lambic, it has aspartame added, or it is pasteurized. Lambic is a natural product.”<ref name=“WildBrews”>Jeff Sparrow, [[Books#Wild Brews: Culture and Craftsmanship in the Belgian Tradition|Wild Brews: Culture and Craftsmanship in the Belgian Tradition]], 2005</ref>