The Knowledge Behind Aging Meat

Kjell Hedstrom 2017, 2022

Dalarna, Sweden.

Moose cow and calf hanging and dry aging while waiting for the final day of the annual moose hunt. Depending on hunting schedule and ambient temperature it is not uncommon that hunters have to butcher the dry aging moose prematurely. Savvy hunters then switch to wet aging the processed meat cuts to reach at least the minimum 40° C day grades before fåreezing the meat.


Some common questions, objections and comments I hear when the subject of aging meat comes up are:

  • I don’t age deer and it tastes amazing.

  • My deer is tender enough.

  • Why age it? It will taste the same no matter what.

  • After soaking it in Italian dressing for 24h it will taste amazing

  • Backstraps don't need aging. The rest I grind into sausage.

  • Why the hell should I age my venison?

  • You can't age venison. It doesn't have enough fat.

Deer tastes amazing. period. It is possible to screw things up but unless you mishandle the meat the chance is that your recently killed doe or buck will be a treat. So why even think about aging it?

Aging makes venison very tender. The difference is not a little. The difference is huge. There are other benefits to aging meat. As enzymes are breaking down the muscle structure, gaminess will reduce and a significant flavor improvement takes place.

My question to you is instead: Why should you not age your venison?

If you have never aged venison before then please try it - if nothing else, try one muscle cut and age it. It's not hard. You don't even need a dedicated aging space with controlled temperature and humidity. The temperature control you already have access to in your fridge will work just fine. Just vacuum pack the meat, put it in the fridge and follow the advice in this blog.

You will get wet aged steak that has improved greatly compared to being prematurely frozen. The chance is high that you just started down the path to significantly expanding your recipe selection, improving your steaks to roast ratio and boosting your future venison taste experience.


When aging meat the meat becomes more tender. The tenderization starts to happen after rigor mortis when the PH drops and activates natural enzymes in the muscle tissue. When this happens the meat, using its own enzymes is breaking down the proteins in cells and binding tissue - the collagen. The aging makes meat more flavorful, more tender, less tough, easier to cut and chew. The following factors have a huge impact on how tender the meat is:

  • how contracted the muscles are

  • amount of binding muscle tissue - collagen

  • fat marbling

Short tenderization time makes different animals (young, old, different species) differ in tenderization. Longer tenderization time reduces or completely removes the difference in tenderization.

A correctly tenderized old buck can be made as tender as a fawn. With aging the flavor of the meat changes - meat that is not aged is lacking flavor compared to aged meat. Meat that is cooked up immediately after the kill is far below the flavor of an aged cut of meat.

For beef, the fat marbling helps the tenderization as the meat can age with significantly reduced moisture loss. Lean wild game can also age and become tender and much more flavorful even if the fat marbling factor is not there to protect and aid the process.

The result after a successful moose hunt in Sweden. Several moose are dry aging in the village big game processing house.

Types of Aging

The most common type of aging in the beef industry is wet aging, a.k.a. vacuum aging. It's cheap, dead simple to get it right, and generates an excellent result.

The most well-known method of aging meat among hunters is dry aging. It is well known that the more expensive dry-aging method will produce the best quality meat, at least slightly better than the result from wet aging. The main disadvantage with dry aging is that it requires more from the locale in terms of space and controlled temperature and that there will be more waste [*].

Regardless of wet aging or dry aging, the end result can vary greatly depending on how long the meat is aged. This blog aims to give you knowledge about how long the meat should age and how to get the same, great-tenderized meat, every time, in spite of temperature variations.

[*] When dry-aging in proper conditions a pellicle, a hard, dry surface, will form on the outside of the muscles. This surface area is also protecting the meat from bacterial spoilage since the bacteria need moisture to thrive. Having a dry surface is beneficial for the internal meat quality. The downside with the pellicle is if it goes to waste, and many choose to trim this away.

The pellicle is just dehydrated meat. Instead of throwing it away, try grinding it, and use it for chili or other stews. My preference is to label the ground pellicle trim as "thirsty ground meat". This ground meat will rehydrate during cooking and will taste absolutely fine.

The °C day grade measure system

It turns out that most advice for aging meat is not given in specifics - it's a range of days and temperatures. Unless you know the relationship between tenderization, temperature, and time you can easily fail to produce the tender and flavorful meat you are striving for.

What we really want is a system to measure the aging process and to get the same, excellent result, every time. Aging meat should be done in cool temperatures to avoid spoilage by bacteria. With that in mind, the breaking down of collagen - i.e. the tenderization process, will be more rapid as temperature goes up and slow down as temperature decreases. When we age an animal we would ideally like to get the same great result every time, regardless of temperature variations. It turns out that such a system to measure the aging process already exists and is used by hundreds of thousands of well-educated hunters - in Scandinavia. It is time we start using this system also in the USA.

The °C Day Grade Measurement System

  • So, what is this Celsius° day grade measurement system?

  • How can you know that it makes sense?

  • Why use a Celsius° system when Fahrenheit° exists?

  • Why haven't I heard about the "Day Grade" system before?

This article will try to answer these questions and make some comparisons between advice I have found from American experts on hunting and meat processing. This article will give you knowledge on how long, temperature-dependent, aging you should give your next deer or elk.

It is the purpose of this article to give you the information needed to age your meat the manual way, or through the foolproof process using our tenderization timer.

So, what is this Celsius° day grade measurement system?

The formula is simple, within a span of reasonable temperatures, the aging of meat follows a similar pattern that can be explained as follows:

  1. The average Celsius temperature for the day (24h) is called the day grade

  2. When the cool, average ambient temperature has reached a total of 40°C day grades the meat has aged its recommended minimum time. Since we should only age meat in cool temperatures reaching 40°C day grades will take some time.

  3. 40°C day grades is considered the generic minimum - and please keep in mind that older animals can benefit from longer age time. Younger animals do not need as much aging time but it will not hurt either. Some small game like jackrabbit, rabbit and squirrels benefit from longer aging time.

  4. The rate of tenderization decreases rapidly after 40°C day grades, i.e. 80°C day grades does not mean the meat is twice as tender as 40°C day grades.

  5. 60°C day grades is my personal preference

  6. Meat should be aged at low, preferably fridge cool, temperatures. My recommendation is to keep the meat aging between average temperatures of: 37°F - 41°F (2.8°C - 5°C)

    Under the right conditions with a carcass that is not contaminated and with a well cleaned gun/arrow penetration area it is not uncommon to dry age meat in 45 - 50
    °F i.e. 7° C - 10° C

  7. Example of average day temperatures to reach 40°C day grades.

  • 50°F equals 10°C. 40/10 = 4 ---> 4 days.

  • 38°F equals 3.3°C. 40/3.3 = 12 ---> 12 days

Quarters, backstrap and some of the finished vacuum packed result - ready to go into the fridge for at least the minimum 40° C day grades.

Recommendation: Unless the meat is in a well-controlled environment the temperature will fluctuate.

If the animal is dry-aging in a barn or in a garage you can count on big temperature variations during 24h. Even in a fridge, there will be temperature variations.

I strongly recommend that you try out the tenderization timer. The small, energy-efficient, and robust timer measures the ambient temperature every 21 seconds and calculates the average day grade temperature. The timer is the best way of getting the same, consistent, tenderized result from one animal to another, year after year.

Why use the Celsius Day Grade System? Why use a Celsius° system when Fahrenheit° exists?

The timer and manual calculation in the day grade system both use the Celsius Day Grade calculation. I am sure you could create a Fahrenheit system but with the proven Celsius Day Grade system, why bother?

Example of the difficulty with Fahrenheit to measure aging:
°F to reach 40°C day grades (rounded values)
· 35°F equals 1.67°C → 40/1.67 → 24 days
· 40°F equals 4.4°C → 9 days
· 45°F equals 7.2°C → 5.5 days.
· 50°F equals 10°C → 4 days

Compared this with °C to reach 40°C day grades.
· 1 °C → 40 / 1 40 days
2 °C → 20 days
4 °C → 10 days
... or with increments of 5

· 5 °C → 40 / 5 → 8 days
10 °C → 4 days.

The °C is tightly coupled and with biological processes from 0°C when water freezes, and 100°C when water is boiling. This makes °C easy to understand when dealing with aging meat.

Manual tracking of C°day grades using thermometer, pen, and paper works great. Even better is to use the tenderization timer - making it easy, foolproof, and helping you to predict and plan when the animal should be butchered.

What the hunting and wild game meat experts say, and how it compares to the °C day grade measure system

Q: How can you know that it makes sense?

Below are 5 examples of different aging advice from some very knowledgeable people. Let us see how their advice is on the day grade measurement scale compared to my recommended minimum aging time. My recommended aging day grades are 40°C as a minimum but my preferred, well-aged, value is 60°C day grades. With this comparison, I hope to show you that the minimum of 40°C day grades makes sense.

Values are rounded.

Cabela's Hunters Harvest, 2017: Age in 34°F - 37°F for 7 - 21 days.

Rocky Mountain Elk Foundation: Age above freezing and below 40°F - deer 10 days, elk 14 days.

Note: The upper range is used in the table. As seen from the Cabela's table above the cooler temperatures requires more than 10 or 14 days.
Update: This link is broken which is a shame. Here's the last waybackmachine's copy of it [and a pdf backup]

North Dakota State University [NDSU article, easy read pdf]: Age in 34°F - 37°F for 10 - 14 days. Sufficient with 2-3 days.

Fairly similar to Cabela's advice.

Opinion: Disappointingly low aging is recommended by NDSU. Maybe they should do a taste test ?

Hank Shaw is within the range of reasonable day grades worth of aging. The danger here is the fairly high temperature. The meat and the aging environment must be impeccable to avoid spoilage by bacteria. It is safer to age in cooler temperatures for longer time.

The focus on Shaw's article was on pheasants and not big game. Regardless, it it safer to age your big game, small game, pheasants or other game birds at a lower temperature. Georgia Pelegrini, How to Age Venison ... 40°F for 7 days - but up to 17 days.

Mule deer venison wet (vacuum) aging until 60° C day grades

I tried googling for "40° C Day grades system" ....

Q: Why haven't I heard about the "Day Grade" system before?

If you did a google search on the topic, the likelihood is that you did not find anything for the Celsius Day Grade system - except maybe the blogs onTasteOfTheWoods. The reason is simple. The °C Day Grades system was created in Sweden, and is so far used mostly in Scandinavia. These hunters, chefs, butchers etc that blog and write about it use Norwegian, Danish, and Swedish. If you instead search for "40 dygnsgrader" (Swedish) you would get several thousand hits.

Below I have collected some Swedish and American articles on aging and closely related topics that I think are worth reading. The Swedish ones also come with a Google Translate link. In case the translation stops working you can always put the URL for the Swedish article into Google Translate to get an updated translation.

American Resources

  1. Field and Stream: Deer Hang Time

  2. American Hunter: How to Age and Braise Venison by Georgia Pellegrini

  3. Hunter Angler Gardener Cook : On Hanging Pheasants by Hank Shaw

  4. Rocky Mountain Elk Foundation: Dry Aging Timeline by John McGannon -- 2022, the link seems to be broken and the article removed as it doesn't show up in a search. Backup from waybackmachine.

  5. Deer Recipes Online - How to Age Venison and Why you Should. -- 2022, the link seems to be broken and the article removed as it doesn't show up in a search. Backup from waybackmachine.

  6. RealTree: 12 Reasons Why Your Venison Tastes like Hell

  7. Legendary Whitetails: How to Age Venison at Home

  8. Research sources:
    Texas Agriculture & Life Sciences University: Meat Science. Class study material but quite informative:
    Conversion of Muscle to Meat
    - Meat Tenderization

  9. Beef Quality Research: The phases of Rigor Mortis explained (2 min video)

  10. Meat and meat products in human nutrition in developing countries (very informative)
    meat quality

  11. RealTree: The great debate: Aging Venison

  12. Outdoor News: Chef Eileen Clark - Tips for Aging

  13. - Article on aging game birds

  14. The Science of Meat Tenderizer : How do Enzymes work.
    Discovery Express Kids - Made for kids and with a kick-ass clarity to the text.

  15. Penn State University: The Dry Facts of Dry Age

Swedish Resources

The Google translation is so-so. Hopefully it will make some sense :)

  1. Swedish Wikipedia: Tenderization
    Recommended minimum 40°C day grades [translated]

  2. Svensk Jakt: Let the Meat Age
    Swedish Hunter magazine - recommended 40°C to 60 day°C grades [translated]

  3. Svenska Jägareförbundets : 60°C day grades
    Swedish Hunter's Association - recommended 60°C day grades [translated - but lost formatting]

  4. Svenska Jägareförbundets : How You Create Tender Meat
    Swedish Hunter's association. Interview with Mikael Löf from DeVilda Wild Game Processing - with over 1,000 wild games processed annually - recommended 40°C day grades, more if conditions are met [translated]

  5. Skogssällskapet: Good Hygiene and Dry Aging - that's when you get the best meat.
    The Swedish Forest Society Foundation - recommended 40
    - 60°C day grades [translated]