The high concentration of malic and oxalic acid in rhubarb not only makes it so sour - it is also able to stop pathogenic bacteria in the stomach and intestines.
Good to know: Red rhubarb varieties, i.e. with red skin and red pulp, have a finely sweet taste. In contrast to their green counterparts, they contain less fruit and oxalic acid and do not need to be peeled before cooking.
Rinse the rhubarb and cut into small pieces. Bring the rhubarb, lime juice, sugar and 2.5 cups of water to a boil.
Simmer over medium heat for about 15 minutes. Remove from the heat and pour through a cloth-lined sieve, catching the liquid. Pour the liquid into a jug and leave to cool. Serve over ice, if desired.