Besan is the most adaptable batter base in the snack kitchen and also one of the easiest to mishandle, because the same flour must behave differently depending on the dish. A pakora batter must be thick enough to cling. A dhokla batter must be light and slightly aerated. A khandvi batter must be thin enough to spread into a very fine layer and still set firm when cooked. A soggy pakora, a dense dhokla or a khandvi that will not roll nearly always reflects an error in consistency or rest, not a fault in the flour. This reference describes how to avoid lumps, how thick each batter should be, how to judge thickness by eye, how to correct a batch that has gone wrong, how salt and acid affect timing, and how long batter can be held.
Preventing lumps
Gram flour forms lumps easily when liquid is added too fast, because the fine particles at the surface of a clump absorb water and seal dry flour inside. The dependable method has three parts. First, the besan is sifted, which breaks up existing clumps and is especially useful for flour that has compacted in storage. Second, it is whisked with the spices or salt while still dry. Third, water is added a few tablespoons at a time with continuous whisking, in place of a single pour. When lumps appear anyway, pressing the batter through a sieve with the back of a spoon is more reliable than further whisking, which often only breaks large lumps into smaller ones without dissolving them. A balloon whisk reaches the corners of the bowl better than a fork.
Pakora batter, the coating consistency
For pakoras and bhajiyas the batter must be thick enough to form a visible, even coat on vegetables without sliding off, about the body of a thick pancake batter. Lifted on a whisk, it should fall back into the bowl in a slow ribbon and not a thin stream. If it is too thin, the coating fries into a weak, translucent shell that never crisps. If it is too thick, the pakoras turn doughy and undercooked in the middle before the outside browns. Replacing up to about one fifth of the besan with rice flour or cornflour gives a noticeably crisper result, since it fries lighter and is less likely to soften on cooling. A rest of 10 to 15 minutes before frying allows the flour to hydrate fully, which also helps the coating adhere to wet or oily vegetables.
Dhokla and khandvi, thinner and smoother
Steamed dhokla batter is much thinner than pakora batter, similar to a pourable, medium-bodied crepe batter, because it must spread evenly in the steaming tin and rise with the aid of a leavener, whether the quick method with fruit salt or a longer fermentation. Khandvi batter is thinner again, almost like milk, because it has to pour into a very fine, even layer on a flat surface and set into a pliable sheet as it cooks, without rising at all. The test specific to khandvi is to cook a small spoonful on a plate and check whether it firms enough to roll without cracking within about a minute. If it is still sticky or will not hold a roll, it needs more cooking or a slightly thicker batter next time, because a batter that is too thin does not set with enough structure to lift cleanly from the plate.
Judging thickness by eye
Three visual benchmarks cover most uses of besan. The first is ribbon consistency, in which batter leaves a spoon in a slow, folding band that briefly holds its shape on the surface before sinking, suitable for thicker dhokla batters and some stuffed pakora coatings. The second is coating consistency, in which batter clings to the back of a spoon as an even, opaque layer and does not run straight off, suitable for ordinary pakoras. The third is pouring consistency, in which batter runs from a spoon in a thin, steady and almost unbroken stream, suitable for khandvi and thinner dosa-style besan preparations. Comparing the batter with these benchmarks before frying or steaming saves more batter than any rescue attempted afterward.
Correcting batter that is too thick or too thin
Thick batter is the simpler problem. Water is added a tablespoon at a time with whisking between additions, because besan thickens unevenly and overcorrection is easy. Thin batter is harder, since adding dry besan directly risks new lumps. A better method is to whisk a small quantity of besan with a splash of water into a smooth paste in a separate bowl, then fold that paste into the main batter, which blends far more evenly than dry flour. Batter that has stiffened during a rest is behaving normally, because the flour keeps absorbing liquid, and a small water adjustment just before use is nearly always required even when the batter looked correct at first mixing.
Salt, acid and the timing of fermentation
In besan batters that rely on fermentation or a quick leavening reaction, and not on steam alone, salt and acid both influence timing. Salt added early can slow fermentation a little by drawing moisture out of the batter, so some cooks hold it back until closer to cooking in a batter intended to ferment for several hours. Acidic additions, such as a spoon of yogurt or lemon juice in a quick-leavened dhokla batter, speed the reaction with baking soda or fruit salt and give faster, stronger bubbling, which helps when time is short and a lighter texture is wanted. A batter left at room temperature for a few hours should look slightly puffed with small surface bubbles. If nothing has changed after several hours in a warm kitchen, the leavener may be inactive or the room too cool, and warming the batter gently is usually a better remedy than waiting longer.
Resting and holding batter
Most besan batters gain from a short rest, from about ten minutes for a simple pakora batter to twenty or thirty minutes for dhokla, which lets the flour hydrate fully and yields a smoother texture in the finished dish. Batter that has rested, especially in a warm kitchen, normally needs a quick re-whisk and a small water adjustment before use. Unused pakora-type batter does not keep well beyond a few hours at room temperature and is best refrigerated if it must wait, then returned to room temperature and whisked again before frying. Batter containing yogurt or other dairy should not be left out for long, and any batter that smells sour when it was not meant to ferment should be discarded.