"I asked Al-Hasan about At-Tila' (thickened grape juice) that has been reduced to half. He said: 'Do not drink it.'"
Sunan an-Nasa'i Book 51, Hadith 186
← Previous Hadith "When At-Tila' (thickened grape juice) has been cooked and reduced to one-third, then there is nothing wrong with it."

Sunan an-Nasa'i Book 51, Hadith 185 Next Hadith → "I asked Al-Hasan about juice that has been cooked. He said: 'That which has been cooked until two-third of it has gone and one-third is left.'"

Sunan an-Nasa'i Book 51, Hadith 187