How do you prepare liquids with a high sugar content into black rectangles?

Question

Suppose that we begin with a fruit juice or other liquid having a large concentration of sugar. Examples are shown below:

• pineapple juice.
• pear juice.
• freshly made juice of sugar cane

How would we transform the fruit juice, or sugar cane juice, into dry hard pieces of un-refined sugar?

Ideally the end product might visually resemble one of the following things:

• brown, yellow, or black rectangles

• beef jerky

• fruit leather

• cut up pieces of a dress belt intended for formal clothing at a Wedding or job interview

• a black strap or "cinturon negro" en Spanish.

• piloncillo from Mexico, but flat in easy to break pieces.

Answer 1

As mentioned in a comment, this question is a bit ambiguous. However, there are a few things that might get you going in the correct direction.

My first assumption from your question is that you are asking about refining sugar from various organic materials. The simplest way is to crush/mash/grind the substance and slowly cook it in water while periodically squeezing the liquid from the pulp. Once you have saturated the water with the sugars, you can simply dehydrate it either by gently cooking to reduce the water content, or by letting it air dry/naturally evaporate. With this method, for quicker results, you can use a nucleation point: string, rod, etc. Something for the sugar to start crystalizing on to. Otherwise, you simply let the moisture evaporate and you will be left with the larger crystalline sugar. This can then be ground up into finer sugar and packed into whatever shape you want.

If you are, instead, referring to dehydrated fruit or vegetable matter, again, basically just another form of dehydration. You can freeze-dry (cycling it in low humidity freezers with intermittent thaw periods), sun-drying, and even smoke dried.

Answer 2

This process as I understand what you desire is done commercially through evacuation; boiling the water away by reducing the air pressure as close to zero as you can.

There are home vacuum chambers you can buy or make.

Answer 3

It's difficult to get the exact thing you're suggesting.

What is easy is treacle. You just cook the juice down until it's quite concentrated, and when it cools down, it has a honey-like consistency and a rather dark color. It's then usable either as a sweetener or as a jam substitute.

The most accessible way to get it concentrated until it's hard is to continue heating it until the rock stage. The problem is that the impurities will interfere with the process, and may burn before you've hit the desired temperature. Also, I don't know what quantities you're planing to make, but candy making is difficult in a typical treacle situation, where you're dealing with tens of liters of the stuff at once, frequently over an open fire. Of course, if you just want a small quantity, you can use normal equipment.

Once you have made your hot sugar solution, the way to get rectangles is to pour it into molds of the desired shape. Silicone is the easiest to work with, but you may be able to also use polycarbonate.