 When describing the uses of common hogweed , John Gerard , a 17th @-@ century English botanist , observed that " the people of [ Poland ] and Lithuania use to make [ a ] drink with the decoction of this herb and leaven or some other thing made of meal , which is used instead of beer and other ordinary drink . " It may suggest that hogweed soup was on some occasions combined with a fermented mixture of water and barley flour , oatmeal or rye flour . Such soured , gelatinous flour @-@ and @-@ water mixture , originally known as kissel ( from the Proto @-@ Slavic root * kyslŭ , ' sour ' ) had been already mentioned in The Tale of Bygone Years , a 12th @-@ century chronicle of Kievan Rus ' , and continued to be a staple of Ukrainian and Russian cooking until the middle of the 19th century . In Poland , a soup based on diluted kissel became known as either żur ( from Middle High German sur ' sour ' ) or barszcz and later – to distinguish it from the red beetroot borscht – as barszcz biały ' white borscht ' . 
