The ratio for syrup depends on the dessert itself. Desserts such as baklava and kadayif, which should stay crisp, need a concentrated syrup, with sugar equal to or greater in weight than the water. Revani, shambali, and sponge-textured desserts work better with a thinner syrup because they absorb a lot. Set the ratio by weighing, not by eye, and consider it together with the boiling time.
Syrup does more than sweeten a dessert; it helps preserve its texture. A concentrated syrup contains little water. When it goes into a pastry dessert, it does not soak and break apart the layers, allowing the dessert to stay crisp for days. A thin syrup contains more water and is absorbed more easily, which is what sponge-textured cakes need. That is why there is no single answer to the question of proportions; it cannot be answered without asking which dessert you mean. Whether the same dessert is served hot or cold also affects the ratio, because cold syrup feels thicker.
For layered desserts such as baklava, kadayif, and shobiyet, the sugar is kept close to the water by weight, and in most recipes it is a little greater. After boiling, this syrup runs slowly from a spoon. For revani, shambali, and cake-textured desserts, the proportion of water is increased because their porous texture lets them absorb syrup quickly and in large amounts. Concentrated syrup leaves these desserts sugary on the outside and dry inside. Fried desserts such as kalburabasti and tulumba also need concentrated syrup; otherwise, the dough releases its oil and becomes heavy.
Boiling time is the other half of the ratio. As syrup boils, water evaporates and it becomes more concentrated; so two syrups made with the same measurements can have different consistencies if they are boiled for different lengths of time. Temperature shows the syrup’s consistency most clearly: the thread stage, when it flows from a spoon in a thin thread, forms at about 110–112°C / 230–234°F, and most syrup-soaked desserts are taken off the heat just below this point. Skim off the foam that collects on top as the syrup boils; this foam consists of residue from the sugar and can cloud the flavor.
Measure the ingredients by weight. Cup and bowl measures vary depending on the size of the sugar crystals and how tightly they are packed, so the same recipe can turn out differently each time. Weighing the sugar and water in grams keeps the ratio the same in every batch. The pot matters, too: water evaporates quickly in a wide, shallow pot and slowly in a narrow, deep one. That is why the time must be adjusted for each pot. If you make the syrup in the same pot each time, you learn the timing once and do not need to guess again.
Other additions also affect the syrup. A slice of lemon, a few cloves, or a piece of cinnamon does not bind some of the water, but it changes the flavor. If honey or starch syrup is used, it replaces part of the sugar rather than being added on top. Every added liquid thins the syrup, so account for flavorings after taking the syrup off the heat, not before it reaches the desired consistency. Leftover syrup can be kept in a covered container in the refrigerator for a few days and used for the next dessert.