In the summer, carp are attracted to large bait beds and will eat ravenously. In the winter, however, carp are very selective nibblers and only bite at baits that really catch their interest. The AnglersNet website recommends using glugged boilies, which are boiled dough bait soaked in a liquid attractant, to catch the attention of selective winter carp. Bright colors can also catch the attention of carp in the winter, so use a brightly colored glugged boilie to increase your chances of catching your quarry.
Carp rely largely on scent to detect bait, but in dense, cold winter water, bait scents do not disperse as easily. In his Sportales article, fishing expert Tim Richardson recommends using bait flavored with synthetic solvent flavorings that dissolve readily in water. Glycerine-based flavorings are hygroscopic, meaning that they attract and bind with water, allowing them to spread effectively. Alcohol flavorings are 100 percent water soluble, making them another great choice for winter water conditions.
Experiment with different known feeding triggers to get the attention of carp in winter. According to Tim Richardson, sweetness "is most importantly detected by carp palatial receptors, which are important in helping carp decide to actually eat and swallow a bait or to reject it." Add sweeteners, such as talin or thaumatin B, to your bait to trigger a feeding response. Because carp are bottom feeders, rotten smells, such as n-butyric acid, can also trigger carp to feed. Essential oils are also great carp attractants, particularly in winter. Not only do the smells of anise, geranium, menthol and other essential oils attract carp, but they also boost carp metabolism, stimulating more aggressive feeding behavior and increasing your chance for a strike.
Prebait an area with small amounts of fine, quick dissolving baits to get the carp in the mood for feeding without filling them up. On the Angling Lines website, Tim Richardson recommends using small paste balls or diced boilies in a warm area to draw carp in and wake them up. The bait will quickly dissolve before the carp have a chance to eat their fill, making them hungry for more.