If you’re using fresh sugarcane juice, strain it through a fine sieve or cheesecloth to remove fibres. I like to do this while sipping a bit of juice—it already tastes tropical and sweet, and it reminds me of the sugar-cane fields of Okinawa.

If you’re using the brown sugar + water substitute, combine in a saucepan and stir until the sugar dissolves.

Place the juice (or sugar solution) into a heavy-bottomed saucepan on medium heat.

Bring just to a gentle boil, then reduce to a steady simmer.

Skim off any foam or impurities from the surface—this mimics the traditional process of clarifying the sugar juice to preserve nutrients and flavour.

After the liquid has reduced by about a third (so you started at 500 ml, now maybe ~300–350 ml), stir in the salt and baking soda.

You’ll notice small bubbling changes—this affects the final texture and ensures the sugar solidifies well.

Keep simmering gently, stirring occasionally. Watch the liquid go from amber to a dark caramel-brown colour. The aroma changes: sugarcane-juice sweetness shifts to deep molasses.

In my kitchen I look for when the liquid thickens and when a spoon dripped with it shows a thick “ribbon” that slowly disappears.

At this point the flavour is richer, you’ll detect grassy, mineral undertones—just like what kokuto is known for.

Once thick (~60–70% reduction) and the colour is dark brown, remove from heat.

If you’re using vanilla extract, stir it in now.

Pour carefully into a lined tray or silicone moulds (for small cubes). Use oil lightly if using metal moulds to help release later.

Let it cool at room temperature until solidified—this might take 1-2 hours. For faster set, you can refrigerate briefly, but be sure it’s nearly set first.

Once firm, turn out of mould/tray. Use a sharp knife to cut into cubes or desired shapes.

Store cubes in an airtight container, separated by parchment paper so they don’t stick. They’ll hold well for a couple of weeks.