Keiki paste is a cytokinin hormone which induces growth in the node of a Phalaenopsis inflorescence.
It should not be confused with paste or powder containing auxins, which are used to force the production of roots.
Nodes on Phalaenopsis spikes will form either vegetative growth (keiki) or floral growth (a branch with flower buds).
If the node tissue is already differentiated so that it will become a floral branch, there is no way to change the result.
The trick is to get the paste onto the node before it is differentiated. However, there is no way to predict if an undifferentiated node will become a keiki or a floral branch.
If a new plant is desired, the keiki should be left on the mother plant until it develops a healthy root system and have two or three leaves(for a Phalaenopsis) or canes (Dendrobium). At this point, it can be carefully removed with a sharp knife and planted in its own pot.
Keikis are cut below and above the stem, leaving a small piece of stem on the baby plant.
A separated keiki can be expected to flower in approximately the same amount of time it would take for the cross or species to flower from a seedling. Some species orchids like Phal pulchra keiki frequently and flower while still attached to the mother plant.
If a new plant is not desired, the keiki can be removed at any time. Removing the entire inflorescence after flowering is complete can prevent the production of keikis and result in a “tidier” appearance for the plant.