Kerupuk, known as Kroepoek in the Netherlands and Suriname, is an indispensable part of any Javanese or Indonesian feast. These crackers are not bought pre-made but in a raw state, and the final preparation – frying – is done just before serving.
The key to perfect Kerupuk is the correct oil temperature. If the oil is too hot, the crackers will burn. If it's too cold, they won't expand. Properly fried Kerupuk should quickly float and increase its volume 3 to 5 times.
Heat the oil in a deep pot or wok. The ideal temperature is 170 °C (338 °F). The oil must be hot enough, otherwise the crackers will not puff up, but only burn.
Test the temperature: drop one cracker in. If it puffs up and floats within 5 seconds, the oil is ready.
Drop 2-4 pieces of Kerupuk in at a time. Do not overcrowd the pot, or the oil temperature will drop quickly.
The crackers must quickly puff up and expand. You can gently push them under the surface with long tongs or a wooden spoon to ensure they expand evenly.
Fry for only 5-10 seconds. When they are fully puffed up and light in color, quickly remove them.
Place the finished Kerupuk on paper towels to remove excess oil.
The crackers are best served crispy and warm. Serve them as a crunchy side dish to all Javanese and Surinamese meals.