Palm sugar and coconut sugar are not the same. The former is from the Palmyra or sugar palm and the latter from coconut palm, but both are produced from the sweet, watery sap that drips from cut flower buds. The sap is collected each morning and boiled in huge woks until a sticky sugar remains. This is whipped and dropped in lumps on cellophane, or filled into containers. Because it is not highly processed like brown sugar, the color, consistency, flavor and level of sweetness can vary from batch to batch, even within the same brand
The color can be from light as creamy beige to dark as rich caramel brown, with a soft and gooey consistency, or rock hard, depending on how long the sap has been reduced. Palm sugar usually has a darker color, a more fragrant smoky aroma and a more complex flavor than coconut sugar, though sometimes additives have been mixed in to lighten its color. Palm sugar may also be labeled as coconut sugar and vice versa in some supermarkets. So it is best to buy your sugar by sight and feel (squeeze the plastic container to ascertain its consistency) than by its label. If you have a choice, select a soft, rich brown sugar; if not, any kind is better than none.
Soft sugar makes it easier to spoon out and use, but more often than not, coconut and palm sugars come in hard, crystallized chunks. It is best to cut and peel back the plastic container and place the lump in a bag and hammer it into small crystals for ease of usage. Some people add water and microwave the sugar. However, this often increases the likelihood of spoilage and reducing its otherwise indefinite shelf life. Neither coconut nor palm sugar needs to be refrigerated, as it is soft and moist. Take care to keep it away from heat and exposure to air which may encourage mold growth. If mold begins to appear on the sugar, remove the top half to one inch. The remainder of the dense sugar may still be fine.
Palm sugar and coconut sugar are used primarily for making sweets and desserts, their creamy, caramel-like sweetness also enhances the flavor of curries and rich sauces for savory dishes. Since the degree of sweetness may vary from batch to batch, add enough “to taste.” Substitute with brown sugar only if you absolutely cannot find either. For sweetening light dishes, granulated sugar is preferred over palm or coconut sugar.
The hardened sugar requires scraping with a spoon or a hand-held coconut shredder with sharp teeth. Placing the whole container into the microwave oven for a brief time helps soften the sugar. Some stores carry hardened palm sugar in round blocks, packaged in cellophane rather than in plastic containers or glass jars. Cutting these blocks down with a knife into chunks is easier than trying to scrape hardened sugar from jars. Palm sugar is also available in tin cans in a more syrupy form. It is quite good, better than crystallized coconut sugar, though some people think it has a tinny taste.
Coconut and palm sugars keep well when stored in a cool dry place and do not need to be refrigerated. They are great sweeteners, balancing agents and flavor enhancers for curries and robust sauces. Many coconut desserts are accentuated by their rich, caramel taste and distinctive aroma.