You may be familiar with the term "liquid bread" when it comes to beer, but in Estonia, you can get something even closer to the real thing. Just keep an eye out for kali.
Kali is a drink made from slightly fermented bread. It's like a mix between a beer and a cola, with a sour-sweet taste, a natural fizz, and very low alcohol content. It’s the Estonian variation of the Slavic kvass, and has since become the local answer to soda. The process of making it is rather simple: Just boil slices of rye bread until they're soft, allow them to cool, and add yeast, sugar, and maltose. Leave the mixture to ferment for a day, then sieve it through a cheese cloth. Some people may add a little lemon juice or even raisins to the finished brew.
Street vendors once pushed carts around Tallinn’s cobbled streets selling kali, but today you can find bottled versions in any Estonian supermarket. It’s often dubbed the “Estonian Coca-Cola,” which seems appropriate, since one of the most popular commercial brands of the drink, Linnuse Kali, was bought by the Coca-Cola Company in 2001. But many Estonians swear the supermarket brands are just not the same as traditional kali. In fact, since most commercial versions are not fermented, they cannot claim to be any variant of kvass. Now, the company advertises Linnuse Kali as “A well-loved Estonian traditional beverage with kvass taste.”
Whether traditional or commercial, kali is still very popular in the Baltics, particularly on snowy nights when the sun barely sets.