Don't let your venison spoil

[fasteddie]

From D&DH 

How Venison Spoils

By: Jacob Edson, D&DH managing editor | March 29, 2012

 

 

The key to obtaining top-quality venison starts the very moment you pull the trigger or release an arrow.

By Dr. Phillip Bishop

The first deer I ever took with a bow and arrow was shot just before dark. I was shooting a fiberglass recurve in those days because compounds were an expensive new development and hadn’t yet become widely popular. I was shooting without sights, because I had enjoyed shooting instinctively as a kid, and I had never considered any other option.

I made a good shot on a doe in the edge of a cornfield. My hunting mentor, Bill, happened to be our local professional wildlife manager. When I told him I had shot a deer, he didn’t hesitate.

“We will come back in the morning and find her,” he said firmly. It really wasn’t open to discussion. I asked him whether the meat would still be good. He assured me it would be, and we left the woods quickly.

Sure enough, the night was cold and the next day we found a good blood trail. We then found my heavy fiberglass arrow still intact. A short distance later, there she lay. And Bill was right; that meat was just fine.

The Antlers of a Dilemma
It seems quite often that the best bucks keep to heavy cover until right before dark. We can’t pass up a chance to arrow a nice deer, so we shoot at the last minutes of legal light. And then we pray.

Did I hit him right? Was it too far back? Did I have a good angle? How far will he go? Where will he go? Do I risk trying to follow those dark red blotches with my weak flashlight? What if I jump him; then what? What are the odds he’ll run off our property? Is there anything in these dark woods that might like to take a chunk out of me? If I wait until morning, will I lose the meat to spoilage?

Some of those questions will be answered later, but a couple of them need answers right now, on the spot, before we climb down from our stand. We have all heard tales of venison lost to spoilage.

One of my friends, who was one of the most ardent hunters I have ever known, once butchered a deer himself. He left it in his back yard to soak in clean water, left it too long and lost the entire deer. What a tragedy!

Keeping Venison Safe
Spoilage is excessive deterioration of meat as a result of bacteria, molds and yeasts. When the population of these ever-present microorganisms grows large enough, the meat is spoiled.

In contrast, “aging” meat is deliberate, controlled deterioration that is stopped before it reaches the spoilage state. Controlled deterioration breaks down some of the connective tissue, and the meat is more tender and, perhaps, more flavorful.
The factors that cause meat spoilage are pretty simple. The four key factors in spoilage of a deer are moisture, temperature, time and condition. Of these four factors, temperature is the most important.

Taking a Deer’s Temperature
A deer’s living temperature at rest is about 101 F. Deer, like hunters, heat up if they use their muscles more, so a deer’s temperature at the time of death depends on what it was doing just beforehand.

A deer that has been chased by dogs for the previous 20 minutes will have a higher temperature than one that was calmly browsing when shot and dropped on the spot. A hard-running deer’s temperature could rise about 5 degrees, so a healthy deer’s maximal living temperature would be a bit above 106 F.

Whereas 4 or 5 degrees might seem like a very small increase, warm-blooded creatures (humans included) live within a very tight range of body temperatures with mechanisms (shivering, panting, sweating) used to control temperature variations much like a thermostat.

The ideal temperature for bacterial growth is between 70 and 120 degrees. Under ideal conditions, bacteria can double about every 20 minutes. Therefore, the whole time the dead deer’s meat is above 70 degrees, microorganisms are multiplying rapidly, a condition that only diminishes a bit from 70 down to 40 degrees. After meat temperature falls to 40, bacteria reproduction drops drastically. Meat (not air) temperatures between 30 and 40 are the perfect temperature for fresh meat refrigeration.

How’s the Weather?
The environmental temperature is as important as the deer’s body temperature. The environment includes not just air temperature, but the temperature of the earth and, occasionally, bodies of water. The secret to good venison is quickly cooling the meat. Conversely, the greatest danger to meat is maintaining it at too high a temperature. Due to radiant heating, meat exposed to bright sunlight will spoil faster than meat kept in the shade.

Any time the environmental temperature is 40 F or warmer, spoilage is a major concern. Keep in mind that insulators will hold the meat temperature higher, longer. For example, most of the time, a deer that is left on the ground will spoil more rapidly than a deer that is hung from a meat pole and exposed to air. The only exception would be in weather conditions wherein the ground is very cold compared to the air temperature.

Several years ago, I was helping one of my wildlife manager friends recover an early season whitetail that had been shot but not found the previous evening. It took us a while to find the deer, and it was very instructive to see the results. After we pulled off the hide, it was striking to see how the “down” side of the deer carcass had spoiled, while the “up” side still looked and smelled fine. However, I would recommend against eating any meat coming from a carcass that gave any signs of spoilage.

Moisture Matters
One of my friends was hunting in Wisconsin about 15 years ago, during a rainy gun season. They had two deer on the meat pole and the temps were in the high 30s. Within two days, even in these cool conditions, they lost both deer to spoilage.

Spoiling microorganisms need moisture. That’s why dried meat, such as jerky, will last a long time without refrigeration. In fact drying, of all sorts of foods, is one of the oldest means of food preservation.

When venison is exposed to air, the outer surface dries somewhat, reducing bacterial activity. When that meat is exposed to moisture, such as rain or even high humidity, the spoilage rate is greatly accelerated. That’s why some experts recommend against washing out deer carcasses unless they will be refrigerated quickly.

If the deer cavity is exposed to intestinal contents, it is wise to wash this area to remove as many of the associated bacteria as possible. However, don’t wash any of the clean areas, unless the deer will be refrigerated. Likewise, if deer have to hang for a few days, hang them in a dry location.

Condition of the Deer
The rapid multiplication of microorganisms, which we call decay or spoilage, doesn’t commence until after death. Healthy, living animals have intact immune systems which keep harmful micro-organisms in check. Sick or infected animals are unable to keep these harmful bacteria, viruses, yeasts and molds at safe levels.

Ironically, when we shoot a deer and don’t recover it immediately, it is better for the meat if the animal lives as long as possible because this results in a shorter time the carcass will spend growing bacteria at a high rate. Although ethically we ought to do everything in our power to achieve a quick and merciful kill, systemic spoilage only begins once the animal dies.

After the animal expires, the spoiling microorganisms begin their unhindered multiplication. Because these spoiling organisms multiply most rapidly in warm, wet environments, the longer meat is held to these conditions, the more rapid the rate of decomposition.

Deer intestines are a reservoir of bacteria. If the intestines are damaged by an arrow or bullet, the bacteria will leave the enclosing barrier of the intestines and fill the gut, hastening spoilage.

Freshly killed gut-shot meat provides an ideal environment for rapid reproduction of microorganisms because it is high in bacteria, moist and provides the microorganisms with good nitrogenous “food.” This food is high in vitamins and minerals and is at a good temperature for microorganism reproduction.

Keep in mind, too, that simply recovering a deer doesn’t stop spoilage. The more rapidly the organs and the blood can be removed, the faster the hide is removed, and the faster the meat is cooled, the better the meat will be.

A Question of Time
So, the conditions of the environment and the deer both help determine the time between shot and recovery without spoiling venison. If the air temperature is 50 degrees, we have three to six hours to recover a deer after it dies. If the temperature is higher, or the animal has elevated its temperature by running hard, then the safe time available for recovery is shorter.

Keep in mind that it is not the temperature at the time you shoot the deer that matters; it’s the expected temperature experienced by the carcass that matters. So if you shoot a deer at 50 degrees, but the skies are clear and you expect the temperature to fall into the high 20s that night, your deer is safer than if the temperature is 45, it’s cloudy with an approaching warm front and the night temperatures are going to stay above 40.

Remember, unless venison is frozen, it will eventually spoil at any temperature — even in the refrigerator.

Decision Time
So, do we go after our deer in the dark, or wait until morning? We need to ask ourselves a few key questions. Where was the deer hit? A double-lung shot means the deer dies quicker and might be easier to find.

However, if you don’t find the deer quickly, and you are sure you got a good chest hit, then spoilage commences as soon as the deer dies. If the shot accidentally hits the deer in the gut, the deer is likely to survive a while, delaying the onset of bacterial multiplication, but it is likely going to be hard to recover. In this case, unless it is very warm, it seems waiting for light is the best option. If the temperature is 40 F or higher, we have little choice and need to make an effort to find the deer as soon as possible.

In that scenario, the wisest approach would be to give the deer one to two hours and then begin the search. We need to use the waiting time to get organized, get help and get the proper equipment, including several strong lights, something to mark the trail, and a coordinated search plan for us and our helpers.

Time is of the Essence
After we recover a deer, we need to get it as cool as quickly as we can. This means getting the organs out quickly, keeping the intestines intact (don’t spill the bacteria), spreading the chest and abdomen open, and getting the carcass off the ground. The hide and hair are good insulators, so get them off as quickly as feasible. Keep the carcass as clean as possible so as not to introduce more bacteria to those already present.

The smaller the pieces of meat, the faster it cools. Use whatever means available to cool the venison. If ice or ice water is available, use these to cool the carcass. Ice water cools more effectively than un-melted ice because the un-melted ice has air pockets that insulate the meat and slow down the cooling process.

Freezer Storage
Meat not immediately eaten should be frozen quickly. Meat with a large surface area, such as ground meat or sausage, has a much greater exposure to bacteria and, hence, is more inclined to spoil.

Packing an entire deer into a small freezer will slow the rate of freezing of the interior meat. This usually won’t matter, but for meat that has had a long exposure to warmth, even a little more time increases bacterial action.

Great Eating
Venison is one of the healthiest meats we can eat. It’s sometimes difficult to acquire, but it’s delicious. One of the keys to quality venison is making good tracking decisions, keeping the meat clean, and cooling it as quickly as possible.