Smell & Taste: How Bass Use These Senses to Feed

Despite the fact that olfactory experts regard humans as having a weak sense of smell, it’s an important one involved in eating and many other activities. I write this article as Christmas approaches, a time of many olfactory delights. Our fresh-cut tree brings back memories of Christmases long past, while my wife’s apple pie cooling on the stove gets me salivating, though I’ve just finished lunch. We sniff suspect leftovers in the back of the fridge, and get the turkey carcass in the garbage bin as soon as possible.

But compared to some creatures, we have little comprehension of the chemical world around us, even as we puzzle at the way the pet pooch sniffs everything and seems to follow invisible trails. Tests show that we can smell a strong odor, such as perfume, at about 30 yards. But scientists say that dogs are one million times more sensitive to scents than we are, and that bears are about seven times as powerful sniffers as bloodhounds. No wonder they readily find their way to garbage cans and bird feeders when natural prey are scarce.

Scents in Bass Fishing

Fish, in contrast, live in the aquatic environment where they’re more or less bathed in the scents of other aquatic creatures, including potential food items. Like us, bass savor flavors and use them in their feeding, but they’re weak in that regard, compared to other fish species. Dr. Keith Jones, the now-retired head scientist as Berkley’s fish lab in Spirit Lake, Iowa, completed his Ph.D. in fish olfaction at Texas A&M University, and went right to work in 1985, devising lures that appealed to gamefish, based on their sensory capabilities.

”A review of the scientific literature shows that trout possess a rather powerful sense of smell,” Jones reported, “which isn’t surprising considering their close relationship to salmon, which use olfactory cues to make their way over hundreds of miles to their spawning locations, the same ones where they’d hatched, ignoring the scent of similar streams along the way. But they still can’t compare to the sensitivity of eels, which likewise must migrate, or catfish, which could be considered the most powerful sniffer, since they focus this sense on both feeding and social interactions.”

He initially worked to determine amino acids flavors that appealed to trout, eventually working with Berkley’s chemistry staff to create paste- and doughbaits trout can’t resist, to the extent that they’re banned on certain streams limited to artificial lures only. “With their less acute sense of smell, bass are more challenging,” Jones says, “but we were able to identify a set of amino acids, the building blocks of proteins, that bass react positively to. They can detect just a couple of ounces of an amino acid mixed into 6,000 gallons of water.”

Taste—The Final Test

While their sense of smell is important for alerting bass to the presence of potential food, the sense of taste is the final decision maker on whether an object is eaten or rejected. Video footage shows that bass can reject an object within a split second after engulfing it, far faster than an angler can set the hook. This sense can play an important role in the success of lures for that reason. Bass are primarily sight feeders, so their eyes direct most strikes, with input from the lateral line as well. But once a lure’s in a bass’ mouth, the taste buds evaluate its palatability. Attractive flavors or customary ones from common prey are quickly swallowed. Negative cues mean a missed fish.

“Like us, bass have taste buds located in the mouth,” Jones says. “But while only our tongue detects tastes, bass have taste buds throughout the mouth area, including the lips and the gills. Each bud has gustatory receptor cells that send messages to the brain. For fish, the senses of smell and taste both detect waterborne chemicals, so the two senses often work in unison when feeding.

“Many of us have seen largemouth and smallmouth bass butting topwater lures with a closed mouth. I feel that this curious behavior may be attempts to taste a lure before turning to eat it. I’ve watched bass do this in the lab and their actions are directed. They’re not making a mistake or miss-timing the strike.”

The Quest for Tasty Baits

At In-Fisherman, we’ve always covered any lures and tackle relevant to a topic at hand, without regard to the size of company or its advertising budget. But while several other lure companies have focused for a time on flavored baits, or incorporated attractants into softbaits, Berkley stands above all the others in their efforts to investigate the scientific background behind the attraction of lures, and their willingness to devote millions of dollars into building and staffing research facilities to fully evaluate products before they get to market.

When I joined the In-Fisherman staff in 1988, we received the first samples of Berkley PowerBait to test. Bass and other species immediately made their attraction to its flavors obvious. PowerBait was the first result for bass of their biological and chemical investigations. And softbaits made with it soon saw excellent sales, as anglers reported excellent experiences with it. Today, it’s been reinvigorated by even more potent flavor formulas and new shapes.

Further research eventually led to the development of Gulp!, a water-based polymer rather then an oil-based formula like PowerBait and nearly all other softbaits on the market. PowerBait is infused with potent attractants but they aren’t readily dispersed. In fact, when PowerBait lures become tattered or cut, they often work even better, as more formula is released from the plastic. Berkley chemical researcher John Prochnow notes that water-based polymers allow more attractants to disperse into the water, and a wider variety of odors can be included in them. “Fish can smell water-soluble liquids better than anything else,” Prochnow says, “and this material allows the lures to hold and then release much more scent. We also packaged Gulp! baits in our Gulp! Alive! solution, which contains hydrating modifiers, which increase absorption. This liquid allows anglers to recharge their baits. After fishing a Gulp! softbait for a while, flavor dispersion is reduced, but they’re easily brought to full strength in Gulp! Alive! juice.” This also helps prevent one issue with Gulp! baits—they dry out quickly in warm sun and wind, to the extent of having to be cut off the hook.

Berkley’s MaxScent is the latest generation of flavorful lures, designed to combine the advantages of PowerBait and Gulp!, while eliminating their drawbacks. Jones and Prochnow worked for years to come up with a product that’s easy to use and extremely effective. “We wanted a material that yielded excellent action, was flexible and durable, had a long shelf-life, and could be easily packaged,” Prochnow says. “And most of all, it had to catch a lot of fish.”

Pro Pointers

Once they got samples to test, bass pros have realized excellent results with MaxScent baits. Justin Lucas lives near Lake Guntersville, one of Alabama’s best and most popular reservoirs. He recalls testing the first samples he received of the General, a 5-inch stickbait.

“I first tried it around Guntersville’s many docks,” Lucas says. “I could tell there was something special about it, as I was getting bites regularly, from fish of all sorts. And when a bass bit, they’d engulfed it and were easy to hook. Bass see a lot of lures here, but MaxScent clearly stands out, and I have to think it’s their scent and flavor.” He had success skipping a wacky-rigged General under docks, impaled on a Berkley Fusion 19 drop-shot hook.

Josh Bertrand of Arizona, a longtime Berkley pro-staff member, has been using MaxScent baits for three years. “The 5- and 6-inch General is a great bait for shallow bass in all sorts of cover,” he says, “and I’ve begun using the 4-inch version as a drop-shot lure.” At the 2018 Bassmaster Elite tournament on Lake Oahe, South Dakota, Lucas and Bertrand both finished in the top-10 by drop-shotting a MaxScent Flat Worm for the lake’s abundant smallmouths, which were on a tough bite in a postspawn funk.

“The bite was tough,” Lucas says. “I was fishing around a group of competitors and we were all drop-shotting or using Ned rigs. I was catching more bass than they were, and I think the attractive scent and flavors of MaxScent kept those smallmouths interested.”

*In-Fisherman Field Editor Steve Quinn has been writing on bass topics for In-Fisherman publications for over 30 years.

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