Help - Oil Liquid Into Solid In Rising And Cooling Water Column

Dec 2016

I am trying figure out a fast and simple way to create 10mm spherical balls of cocoa butter in a production line type environment. I want to avoid the time it takes to pour the mass into molds, cool them, and then have to remove them. I have an idea and would appreciate feedback and input.

The concept is to take a clear, plexiglass pipe, and set it vertically. I am not sure what the best diameter would be, but for now I will say it is 4 inches in diameter. The height is also questionable but for now I will say 7 feet tall. This pipe would hold water. The water will need to flow slowly upward, so I will need an entry hose at the base and an outflow at the top. The water temperature will need to be cooler at different sections, from warmer at the base to coldest at the top. A small metal pipe/tube will enter 2 inches into the side of the plexiglass pipe at the base, ending at the center. This metal pipe/tube is how the cocoa butter might be introduced as a liquid or semi-liquid mass. As this mass rises inside the plexiglass pipe and cools, the "plan" is for the ball to end up as a 10mm hard ball of cocoa butter.

So I have a lot of unknowns and questions. I expect that much of this will be learned and determined with experimentation. My biggest reason for this post is feedback on the concept. Maybe someone will tell me that a spherical ball can’t be produced this way because the cocoa butter will rise too fast to maintain a sphere, or that it will break apart as it rises. Maybe I do not understand that there will be a battle between the rising, forced flow of water and the sinking of the cooler water that creates too much turbulence, ruining this idea.

The cooler water at the top would sink and the warmer water at the bottom will rise. This is why I believe that I need to manipulate the water flow upwards. I have to figure out what the best plexiglass diameter will be as well as the upward water flow. The water flow should be as just enough to keep the cocoa butter ball rising.

There are a number of simple ways to cool the water. I am thinking of building plexiglass 5 sided open top boxes that the column with pass through the center of and maintain the water temps in that box. Each successive box upward on the column would be cooler. Or just put an electric cold wraps at intervals with different temps. Whatever way is best I know there is a solution.

What is the best diameter for the plexiglass pipe? Considering the ball diameter size of 10mm and the upward flow rate, it may be best if it were smaller than 4”.

What is the necessary height of the plexiglass pipe?

How to best introduce the cocoa butter mass into the column of water so that is does not break up and can best form a consistent 10mm ball. This is an unknown to me. It may not be possible to end up with a consistent spherical ball at the top.

Will the ball need to be manipulated as it rises, cools, and hardens in order to maintain a spherical shape? Can this be done by spinning with a water jet, or rolled with some type of mounted metal form fixed inside the column, or another idea?

I live in the Los Angeles area, so if anyone is close, maybe I can work with them to advance this idea.


Jeff 310-936-2447
Last edited:
Jun 2016
This sounds reasonable,
I think the key is how hot is the coco-butter at the start,
and how cold must it be at the end.
This tells you how much heat needs to be transferred to the water.
I would suggest that the balls need to float gently to the top,
rather than be driven by the water circulation.
(I assume coco-butter does float in water...)
The circulation will be just to take the water through a cooler
(and possibly a filter to remove finer droplets of coco-butter that might form).
I might suggest two concentric pipes, one inside the other.
The outside pipe carries cold water from the refrigeration unit down to the bottom, cooling the inner pipe along the way.
The water then flows back up the inside pipe cooling the butterballs on the way.
The water circulation will be just enough to match the required heat transfer rate.
The height will be determined by the rate of heat transfer from the balls to the water, and how quickly the balls float to the top.
An alternative might be to have the water flow down the column,
as long as the flow is slower than the rate at which the balls float upwards they will still reach the top.
but because they are floating against the flow, they will rise slower, so the column need not be as high.