A Scent Control Case Study: Does It Really Work?

There might be some legitimate scientific studies that show if scent control works, but if so, I’m not familiar with them. I have read accounts of a few tests using trained dogs to find hunters under boxes. But in my opinion, these lack validity. Too few data points, deer being a different species than dogs, and the fact that a person hiding under a box in an open field is vastly different than a hunting situation are all reasons to disqualify these results, in my mind.

Instead, the best analysis of scent control efforts may be a simple A/B test on whitetails conducted while hunting. This can be done by any hunter and potentially include hundreds of data points over multiple seasons. And the results of both before and after a scent control regimen can be compared. Case studies like this are a valuable analysis tool, so let’s look at one 32 years in the making — my hunting journey.

A Few Misconceptions

First let’s define what scent control is and is not. The term “scent-free” is often thrown around and misleads hunters to think they can eliminate all odors coming from or left by them. But is this what you need to do? In a recent discussion I had with Dr. Karl Miller, former professor at the University of Georgia Deer Lab, he mentioned something that I believe is the key. He said: “There is an odor threshold above which deer adversely react, and below which they do not.”

Deer have many more scent receptors than humans, a larger area of the brain dedicated to process odors, and the ability to sort odors far above a human. However, there is still a threshold of odor molecules that if not exceeded, will not trip a whitetail’s trigger.

Our goal therefore should simply be eliminating enough of our scent to fall below Dr. Miller’s odor threshold. This should include both contact odors (left by touching brush, twigs, trees, and what we transfer while walking) and also airborne odors we emit from our bodies and gear.

The Early Years

When I hit the woods for the first time as a 12-year-old, I wore blue jeans, a green hoodie and had zero scent control. I specifically recall hunting over a bait pile, and nervously shaking for over 20 minutes as a “monster” 6-point stomped and snorted downwind.

Apparently, the gnawing in his stomach couldn’t override the stench in his nostrils, and this is the way it was that first entire season. In fact, my dad’s hunting journal details that I spent an incredible 100 hours hunting with no success. Over my first 19 seasons one thing became a fact to me; if a deer got downwind, it would smell me and adversely react. And I had hundreds of occurrences over those years to prove it. We’ll call these snorts, stomps and white flags “data points” for this case study.

This is where I want to introduce a simple graphic organizer to visualize these occurrences, and also to show how anyone can track their own experience. It might err on the side of being simplistic, but I believe it shows the big picture of what is going on. The challenging part of a scent control regimen is measuring its effectiveness, which is best seen by an adverse reaction, as it’s difficult to tie a non-reaction directly to any one cause.

However, through a quorum of hundreds of observations, I believe trends become beneficial. Measurements I collected were both adverse and non-adverse reactions by deer when downwind or where I left contact odors that a deer could sniff.

My first 19 years have hundreds of encounters, data points mostly in quadrant 2 — no scent control (X-axis) and adverse reaction (Y-axis). Very few fell in quadrant 3 (no adverse reaction), and none fell in quadrants 1 or 4 since I was not practicing any scent control. The red horizontal line through the middle represents the odor threshold mentioned by Dr. Miller.

The vertical black line in the middle represents when I began practicing and evolving my scent control regimen around 2010. Since then, I’ve had hundreds of encounters with deer downwind of me in the hunting situation with results that even surprised me.

The Scent Control Era

It began when I read a post online about a hunter using garbage bags to store his clothes so smoking Marlboro’s in his Chevy wouldn’t contaminate them. This, along with prevalent scent- free detergent advertising got me thinking about a couple simple things I could try. These included washing my clothes in scent-free detergent and sealing and storing them in standard garbage bags.

I also tried an antimicrobial shirt that first year, and distinctly remember an encounter on public land in Michigan soon after (where edgy deer routinely would look up in trees to find hunters).

A group of does began meandering downwind of me as I watched from my tree stand perch in a thick bedding area. As they did, I got nervous, because as predictably as the sun setting in the west, I knew what would soon happen — snorting, stomping and a hasty exit. But to my amazement, they did none of that. Instead, they lingered in my scent cone for several minutes, all behaving normally.

I started to become a believer in the possibilities of scent control that day, with data point number one logged in quadrant 4. In the 13 years to follow, hundreds of similar occurrences piled up, data points largely falling in that same quadrant, and in that time I honed my regimen to the point where I currently don’t worry much about wind direction. In fact, a couple years ago, I put it to the test again in that same bedding area.

I’d become confident with my scent control regimen and that deer would not detect me when I used it properly, but I still didn’t purposely set up with my scent blowing directly into a bedding area for hours on end. Where I hunt in Michigan is flat land, so thermals do not come into play as much as they do in hilly terrain. When I arrived at my stand, the wind was blowing straight where I knew the deer were bedded, which was between 50 to 150 yards from my tree with no barrier but tall grasses and sporadic trees between us.

About an hour before dark, the movement began. It started with a spike buck coming from the bedding area and moving headfirst into my scent cone. He proceeded to walk and stay in it for about 80 yards before turning and offering me a chipshot if I had wanted it, never showing any adverse reaction as he continued toward a field.

About 10 minutes later, a group of two does with two fawns also came from the bedding area directly downwind. They came to about 60 yards and stopped. For about five minutes, one of the does raised her nose testing the wind, as if she smelled something.

Apparently, the amount of scent molecules emitted from myself and my gear did not exceed the threshold, and after a while they continued their path right by my stand with no adverse reaction. Lastly, an older 8-point came from the same bedding area, walked the same 80 yards in my scent plume, and offered several shot opportunities before going on his way. Six highly pressured and ultra-wary whitetails were directly downwind for a considerable amount of time with no adverse reaction. My scent control regimen had passed the test.

This same regimen worked for me in 2016 when a buck walked through heavy grass and goldenrod directly on a trail I had followed, crossed my scent plume and offered a shot at 25 yards. He never reacted until the arrow passed through him. And just this past year, I’m sure this regimen was responsible for helping me wrap my tag around a Pope & Young Michigan public land buck. In that case, I evaded a downwind doe group for several minutes, and a subordinate buck that worked a scrape just eight yards downwind as the P&Y buck watched for signs of danger. He saw none.

Since my conversion of sorts to a scent control regimen, I’ve had hundreds of encounters like this, mostly grouping in quadrant 4. Yes, there are times I get lazy, make a mistake and the deer let me know. In those cases, I can usually go through my checklist, find the culprit and quickly fix it. But the amount of these adverse reactions has sharply declined compared to my pre-scent-control days. By the data, my scent regimen works well, and it’s something any hunter can test for themselves.

The Scent Control Regimen

The entire regimen is much too detailed to include in a single article, so I’ll give the main ideas as a starting point. The big key is adopting a no-tolerance attitude toward odors. You cannot allow outside scents to contaminate hunting clothes, gear, hair or skin, because it only takes one contaminated item for a deer to catch you. As the season progresses, this tends to get harder as deer are more on the alert from hunting pressure, and hunters are more apt to get lazy. It’s important you don’t.

Much of the regimen happens before you hunt. Washing all gear in scent-free detergent, making sure to dry it in a sterile environment, and having a storage system to keep out all foreign odors is a must. Your home should also be as scent free as possible, including washing all sheets and street clothes in scent-free detergent. If you skimp and wash towels and sheets in scented detergent, then take a shower and dry off, or get into bed in these sheets with odors, the odors are transferred to your body. Everything in your house must be kept in mind.

Gear such as weapons, stands, climbing sticks, rattling antlers, hooks and anything else should be washed to remove scents or wiped down with scent-free wet wipes. Be sure not to overlook this equipment, especially those that may be ground level to deer (like a bottom climbing stick).

Ozone is a vital part of my regimen as well, but not in the tree. First, your vehicle needs to be treated and kept free of odors all season, as this is where you can transfer scents easily to your hunting gear. It is vital to de-scent all your clothes and gear after each hunt, which requires time and dedication to do this when you get home to prepare for the next hunt. Ozone needs to penetrate into the cloth fibers, and a high-pressure industrial unit is what I use for this.

Food consumption is often overlooked but needs to be analyzed. Since your body creates odor molecules, what you eat literally becomes what you emit. Start a strict diet at least two weeks before the season begins and adhere to it throughout the entire season. Wet wipes before a hunt, activated carbon and hip boots to keep scent off grasses and brush are also a vital part of my system and should be considered. I’ve had many instances where deer travel an exact path I took through waist-high grasses and have no idea I traveled it (the buck I took from 2016 previously mentioned).

Do you think a personal case study like this, with hundreds of occurrences, shows adequate data for making conclusions about scent control? I personally do. The regimen requires effort, but if you can maintain it throughout the season, and keep track of each occurrence in a chart like above, you won’t have to believe me; you can see for yourself a full pdf of this scent control regimen.

About The Author

Adam Lewis has over 30 years of experience hunting whitetails successfully on both private and public lands around the country. He’s an award-winning writer, and creator of Deer IQ, aimed at educating and equipping hunters through podcast, blog, and services found at deeriq.com. Visit his website to download a full PDF of his scent control regimen.

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