All the rare chu jelly locations:

Rare Chus can be found in any area Chus are normally found, however the chances of finding them are substantially lower than 2%. The Cave of Ordeals and a secret grotto under a tree at Snowpeak are the only certain places to find them. Outside the cave, the small ledge on Death Mountain, under the large tree atop Lake Hylia between midnight and dawn, and also near Snowpeak are places reported to have had Rare Chus. A Rare Chu can also be found within a secret grotto beneath Ordon Ranch accessed via a dig spot within the barn.