Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
5 Nov

Dear Mark: Bacon Fat Stability, Noise Machines, and Pig Feed

Is there any food more lauded and feared, beloved and bewitching, hated and praised – all at the same time – than bacon? Have full-fledged Internet subcultures sprung up around any other animal product? Does any food but bacon inspire obvious longing masquerading as righteous rancor and vitriol? And yet no matter how much has been written about bacon, questions inevitably and indefinitely remain. Case in point: today’s round of questions. That’s right, we have two bacon-related questions and one unrelated question about noise therapy and sleep. I’ve got to say – this really warms my heart. Not only are you trying to find pastured bacon and wondering about what the pork you eat is being fed, you’re also trying to figure out how to sleep better. How much more Primal can you get?

Hello Mark,

My wife and I have been keeping our bacon grease to cook eggs and other things for a couple days.  How long can we keep the grease in the fridge before it’s too oxidized or rancid for safe use?

For now we’re using uncured bacon from Trader Joe’s. Any suggestions for finding some pastured bacon sources? We live in Phoenix and have been unable to find it as easily as grass fed beef.



To my knowledge, there aren’t any studies looking at the issue of the oxidative stability of bacon grease, but one study (PDF) looked at the oxidative stability of purified olive oil (antioxidants and other polyphenols removed, just like bacon fat which has zero endogenous antioxidants), which is high in monounsaturated fat (like bacon fat) and low in polyunsaturated fat (like bacon fat, depending on the amount of PUFA in the pig’s diet), when exposed to moderately warm conditions and allowed to sit out in the open. At 40 degrees ºC or 104 degrees ºF – a toasty number, but a believable one if the bacon grease is kept on or around a stove that sees a lot of use – the olive oil was pretty stable for about five days, after which the oxidation products began to slowly rise. At ten days, the rise in oxidation products took off and sharply increased. At 50 (122 ºF) and 60 (140 ºF) degrees ºC, the oxidative products rose sharply almost immediately and maintained their upward trajectory. I think this gives us a decent idea as to the stability of bacon fat, although you should keep a couple things in mind:

If the bacon comes from a pig who ate lots of corn, soy, and corn/soybean oil, it will be higher in PUFAs than the olive oil tested in the study. This will make it go rancid faster.

The bacon grease already got exposed to heat when you cooked the bacon. The degree of oxidation depends on how long and at what temperature you cooked it. Best to go low temperature to keep the oxidation down.

Lesson? When in Death Valley, the Sahara, or camping on the outskirts of Las Vegas in summer, you probably want to toss your bacon grease.

Keeping it in the fridge, where it’s away from heat and light and far cooler than 40 degrees ºC (let alone 50 or 60), however, eliminates two major oxidative stressors. Put it in a sealed jar and you’ve minimized another major oxidative stressor: air (PDF). And you’re only keeping it for “a couple days”? You’re probably safe.

As for pastured bacon in Phoenix, I found a couple promising leads.

Hopkins Hog Farm, located near Aguila, raises their heritage pigs outside in large paddocks and finishes them on pasture. The bulk of their diet comes from freshly-ground grains. No mention as to the types of grains used, but I’d imagine it involves corn and soy. They sell at the Mesa Community, Ahwatukee, and Old Town Scottsdale farmers markets, although I’m not sure if they actually make bacon. Their web page lists a variety of different cuts and sausages, but no mention of bacon. Of course, I’ve never heard of a pork farmer that didn’t do bacon.

M Triangle Ranch is a bit farther out, but this Arizonan who was desperate for pastured pork had great things to say about their truly pastured bacon. She was able to email the owner and arrange for a meet-up point where a clandestine bacon exchange occurred. If you’re ever in Tucson, you might think about looking them up or visiting a farmers market that sells their products.

Date Creek Ranch also has pastured pork. They do receive grains (no mention of which; probably corn), but once weaned, the pigs are turned out and allowed to “root and behave like pigs!”

There’s also The Meat Shop, which has great prices and selection but doesn’t appear to feature pastured pork.

For everyone else, to find quality meat suppliers in your area take a look at Eat Wild and Local Harvest,

Good morning, Mark. I am following a beta test exercise program that also provides weekly challenges. This week’s challenge is to buy a sound therapy machine and use it while sleeping, but with no explanation why/how it is beneficial. I already black out my room, have no ambient light such as an alarm clock, get as many hours before midnight as possible – what is your take on the sound machine?


Ottawa, Ontario

Morning, Linnea.

White noise, which most sound machines tend to focus on, does seem to help people sleep. I started using white noise in college as a means of partially drowning out the all-night-every-night disruptive sounds in the dorm. As an overtrained endurance athlete/scholar, I found I slept much better with the sound of a window fan kept on a low setting. I use that same technique today to actually introduce ambient sound over an otherwise completely quiet (and blacked-out) bedroom. It’s as if too much noise is bad, but not enough is also disruptive. In fact, the first thing I check in a hotel room when I’m on the road is the quality of sound coming from the AC or the fan!

There aren’t many studies, but there are a couple.

In a group of newborns, researchers exposed them to either white noise or no noise. 80% of the white noise babies fell asleep within five minutes of exposure, while just 25% of the control babies managed to fall asleep in five minutes without any noise at all. “White noise may help mothers settle difficult babies.” Of course, they probably have to be out of the womb if white noise is to have any beneficial effect on their ability to sleep. Sorry, fetuses.

To study how the frequently disruptive soundscape in an intensive care unit could be mollified, researchers exposed subjects to several different environments – baseline (no sound), recorded ICU sounds, and recorded ICU sounds accompanied by white noise – through the night and recorded the number of “arousals.” The baseline group had the fewest number of arousals, at 13.7 per subject. The ICU sound group had the most, at 48.4 arousals. The ICU sound/white noise group had just 15.7 arousals, very similar to the baseline group. Since the change in sound from baseline to peak seemed to determine whether or not a subject would be aroused, researchers determined that the white noise “filled in the gaps” of silence with noise, thereby creating a higher “baseline.”

It makes sense, doesn’t it? We know intuitively that sound certainly affects sleep, both positively and negatively. An alarm blaring in the night, the steady drip drop drip of a leaky faucet, and a baby’s wailing seem evolutionarily designed to keep or make us awake, don’t they? Sharp noises in the dead of night can mean scary things, things that threaten a hominid’s immediate survival. Think snapping twigs, the snarl of a tiger, the whoop of a war cry. Our problem nowadays is that aural disturbances are the norm. Cars honk, motorcycles rev, radios blare. White noise appears to be a neutral sound akin to the soothing hum of the wilderness that smoothes out the night.

And of course, any sound that you personally find relaxing/soothing/etc. is probably going to also help you sleep.

Dear Mark,

In an effort to make Primal living more cost effective, we are in the process of purchasing some beef in bulk through a local farm found through Eat Wild. We also eat a fair amount of pork, and I looked at the couple of local farms that produce pork, and they both mention supplementing the pigs’ feed with corn and soy. I don’t know enough about modern pig farming to know whether this is standard practice even within the non-commercial farming arena, or if I just need to keep looking for another source. Is the organic, no hormone, no antibiotic pork I buy now supplemented with corn and soy?

Does it really matter?



I’d say it does matter, especially if you’re going to be forking over a large amount of money for a large amount of pork. The fatty acid distribution of pig meat is extremely sensitive to the fatty acid content of the pig’s diet. If the feed is high in polyunsaturated fat, particularly the linoleic acid predominant in corn and soy, the pork fat will reflect that. And there’s clear evidence that due to the proliferation of cheap corn and soy products (including meal and oils) in pig feed, the typical PUFA content of pork fat has been grossly underreported. As Chris Masterjohn reports, the “new” pork fat has less saturated fat, less monounsaturated fat, and nearly twice the amount of linoleic acid as before, while Tokelauan pigs – given tons of coconut – end up with just 3% of fat as PUFA.

Although you probably won’t be able to get coconut-fed pork, you can do better by looking for pigs given other types of grains, like barley, oats, or even wheat. Pigs fed on these “small grains” tend to have higher quality (read: more firm and less polyunsaturated) fat than corn or soy-fed pigs (PDF). And you probably won’t be able to totally avoid soy and corn; that’s okay as long as the pigs get other types of feed, too. “Supplemented with” is probably okay (but try to find out what else the pigs eat and just how much the “supplement” really is). What you don’t want is a factory-farmed or “pastured” pig that gets the bulk of its nutrition from corn, soy, and vegetable oil.

If you absolutely can’t get a full breakdown of the pig’s feed, before you commit to a bulk order, try to get your hands on some bacon. If the bacon is stiff, firm, and tries to maintain its shape and solidity when held at one end (it doesn’t droop down like a limp noodle), the pig’s diet was likely fairly low in corn and soy and the fatty acids in the bacon are mostly monounsaturated and saturated – as they should be. I’ll sometimes get pastured pork that’s fed on produce trimmings and leftovers plus forage, barley, and oats, and the bacon is pretty darn firm and stiff, even at room temperature. I’ve never run a fatty acid analysis on it, but it certainly passes my subjective taste analysis with flying colors.

That’s all I’ve got for today, folks. Since I’ve mentioned bacon (twice!), I imagine today’s comment section will provide a rollicking good time, so go ahead and have at it. Thanks for reading!

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. We just had a baby (I’m 62 years old & primal) and I picked up an app for my IPhone called
    “Simply Noise”. We first tried it when the baby was fussing it put us all to sleep in about 5 minutes. We’ve now graduated from white down to pink and now are using brown noise which is more like the ocean. Love it and can’t recommend it enough. P. S.( I have no investment in this app)
    Rock on Primal People.

    Doug wrote on November 6th, 2012
  2. If you want to try out a noise machine, the iTunes App Store has one called Mind Tuner, which has some lovely rain & thunderstorm filters. Also great for drowning out noisy commuters :)

    Australians can get duck & duck fat from Luv a Duck & Rougie brand Goose Fat in a lot of European delis. Can’t verify food sources though.

    Praxis wrote on November 6th, 2012
  3. Rainbow Ranch Farms has no grain heritage grass fed pork.

    But I am no longer sure about pork. I didn’t find myself doing too well on grass fed pork. Then I discovered RBTI, health program created by Carey Reams, and found that pork is an energy losing food. “The reason to avoid .. [pork] is … it releases too much heat and electrical energy when processed in the digestion ” Pork contains high levels of phosphate compounds that tie up calcium so it is lost from digestion. (Biological Ionization as Applied to Human Nutrition, p. 224).

    “Dr. Carey Reams considers the following foods as unclean meats that should not be eaten: Hogs, Guinea Pigs, Rabbits, Muskrat, Snakes. The following fish should not be eaten: Catfish, Tuna fish, Lobsters, Oysters, Clams, Shrimp, Crabs and Scallops and shellfish of any kind. These unclean meats release energy too quickly for the body to make use of them. They digest so fast that you cannot use the proteins, which turn into urea and dump into the bloodstream so fast that the kidneys cannot eliminate them. A urea build-up in the body ensues and excessive urea leads to many health problems” (Health Guide for Survival, p.45).

    Energy loss is quantified in RBTI by running 5 tests. A major part of RBTI is the observation that our soils are depleted and thus our foods, so many health problems stem from nutrient poor food crops. Those who have very good health or high reserve energy, to use RBTI terminology, would not be materially affected by eating pork – not that many such people exist today.

    Obviously, hunters and gatherers did not deplete the soil because they did not farm. So, they had better soils and thus better nutrition than today and thus higher reserve energy. Which may be one of the reasons why studies by anthropologists indicate hunters and gatherers had excellent overall health, pork or no pork.

    Has anyone noticed problems consuming pork, including grass fed? I have done great on no grain heritage chicken grown Paleo style by the aforementioned farm and the same with grass fed beef and lamb.

    Jamil wrote on November 6th, 2012
    • I am of the opposite opinion concerning pork. Pigs are just about the only animal raised for nothing but meat. They serve no purpose as beasts of burden and do not produce any edible products while alive. They have evolved to be on the “eaten” end of the food chain. Perhaps industrialization has sapped the nutritive quality from pork at the same time as adding toxins and unhealthy forms of fat, but good quality, free-range pork should be an excellent source of fat and protein. I have no problem with it, and I consider pork in all it’s forms to be one of the most versatile meats available. Almost every part of the pig is edible, tasty, and unique in flavor and texture.

      Mark A wrote on November 8th, 2012
  4. We are lucky, we are friends with a local smallholder, who has just let us have half of their pig. I know that it was fed on household slops and foraging. We have cut it up into all its tasty cuts of meat and also made some bacon. If you can get it, its the best tasting bacon you could eat. The fat melts into the pan, clear and clean, no caramel coloured stuff coming out, like the supermarket purchases we have had before. Its so yummy and the fat is then used to roast veg.

    Charmaine wrote on November 6th, 2012
  5. We raise our own pigs and I am always thinking about what best to feed them. They forage in their pen, get garden leftovers, “slop” from us and various sources but we have to supplement with a little feed. Unfortunately the feed says “grain products” and no detailed breakdown, so I feel better not giving them too much.
    They do love to eat chicken carcasses (we raise our own chicken), but hate bagels and oranges.
    Overall I feel like we are still getting better quality (and better tasting) meat, but I still worry if it is good enough!

    mary b wrote on November 7th, 2012
  6. Wow, I guess I didn’t know that people actually have enough bacon grease that storage is an issue. Usually if I run out of egg or avocado to soak up the grease, I just lick the plate.

    Lesson learned: I’m clearly not eating enough bacon then.

    Jeff wrote on November 7th, 2012
  7. It gets hot in kitchens. Imagine how much of the grease on top of a pizza is actually sweat that’s dripped off a worker’s head or face.

    Animanarchy wrote on November 7th, 2012
  8. I am enjoying the comments but cannot work out where this bacon grease comes from. If you are saying after you cook bacon you tip the grease into a jar and then reuse it to cook other foods then I must admit that I tip the grease on my plate each time I eat bacon, and roll my eggs, mushrooms, zucchini and other assorted breakfast veggies in it and I eat it. I am after all trying for a HIGH fat, adequate protein, low carb “diet”. Does anyone else do this? I eat probably 4 rashers of bacon in a sitting, and the amount of grease after cooking is smallish. Certainly not enough to “save” in my opinion. All this said.. I am Australian… and we do have the “best bacon” in the world… so maybe our bacon is different to yours? When I traveled to USA and Canada and UK I was rather unimpressed with the bacon on offer…

    Jane wrote on November 9th, 2012
  9. Mark,
    “If the bacon is stiff, firm, and tries to maintain its shape and solidity when held at one end (it doesn’t droop down like a limp noodle), the pig’s diet was likely fairly low in corn and soy and the fatty acids in the bacon are mostly monounsaturated and saturated – as they should be.”
    I raise mostly (75%)grass-fed pork, with the rest being Barley, oats, and less than a cup a day per pig of corn and no soy at all. The bacon is soaked in salt water (no chemicals) and then smoked, that’s it. I actually need to add butter to the pan cause it produces next to no grease and it does not get crispy, it stays like you say “a limp noodle.” I have fed my pigs this feed and done the bacon the same way and it turns out the same everytime. I am not sure why, but I don’t believe that less corn and soy equate with crispy bacon and more gives limp bacon. Just my personal experience. Have been doing pigs for years with the same out come.

    Dena wrote on November 9th, 2012
    • Dena, he’s talking about the RAW bacon being stiff and firm. Crispiness of cooked bacon depends mostly on how long and at what temperature you cook it. I have never encountered bacon that would not cook to a crisp given enough heat and time. If you keep doing the same thing, of course it’s going to turn out the same. Could you try cutting out the corn entirely from their diet and see what difference that makes? Or just cook it longer if you want it to be crispy.

      P.S. Where did you get 75%? How do you know how much grass your pigs are eating?

      Frasier wrote on February 15th, 2013
      • Frasier, If he is talking about raw bacon, the yes my raw is slightly more stiff than cooked. You are right about if you cook anything long enough it will get crispy. I made a dish calling for crispy bacon, so I cooked it longer (alot longer)then I had ever cooked store bought and it did indeed come out crispy, of course with the help of lots of butter. When I say grass I mean hay and hay pellets, can not get fresh grass here in southern Arizona unless your willing to spend lots of money on water. I would rather feed them fresh grass, but as it is, my per pound cost is around 5 dollars a pound. I track every cent that I spend on feed. And that cost doesn’t even include water and my time. I would cut out the corn completely if I was breeding my own stock. But I buy the piglets at 10 to 15 weeks and where I get them from, they only feed them corn. So they are very picky when it comes to eating the hay and pellets. It takes about 4 weeks to get them to convert to mostly pellets. I tried just leaving pellets and hay and no grains for 4 days and they would not touch the pellets and ate maybe a quarter of the hay. They do great on hay if they are eating that right out of the shoot.

        Dena wrote on February 16th, 2013
  10. We pasture our hogs (Mulefoot hogs are kosher! lol!) but we DO supplement with commercial feed (yes, there is corn in the feed). I render the lard and it is fantastically pure white (and not “porky” smelling/tasting). I always store rendered lard in the fridge or freezer, simply because it would really hurt my head to do all that work and have any of it go bad/mold. Our hogs also get veggy scraps, apples, acorns, hickory nuts, eggs, etc. We don’t, however, feed them meat (if they get it on their own, that is perfectly fine). When we butcher we do not chemically cure any of the meat–fresh bacon is wonderful and you can add your own salt level :)

    Kathleen wrote on November 14th, 2012
  11. If you could mail me with a few ideas on just how you made your website look this excellent, I would be thankful.

    Cynde Delaina wrote on January 10th, 2014
  12. Is Your Sound Machine Harming Your Child’s Hearing?

    William JTucker wrote on September 13th, 2014
  13. Bacon… bacon bacon bacon bacon, bacon bacon. Bacon bacon bacon bacon bacon and bacon. Then bacon bacon bacon bacon. As far as I can tell, bacon bacon bacon bacon bacon with bacon bacon can and will bacon bacon bacon bacon bacon… unless, of course bacon bacon bacon. Consequently, bacon bacon bacon bacon bacon bacon bacon. So, basically, bacon bacon bacon bacon bacon bacon bacon bacon bacon bacon bacon. At least that’s my opinion.


    Vince G wrote on October 2nd, 2014
  14. i realize i’m way way late to the party by commenting now, but i’ll try…i have a question that i surely hope will be answered by someone out there with the appropriate knowledge… it’s regarding the healthiest way to cook bacon to a well-done state… i have access thru a local raw co-op group to get pastured bacon. I’ve read online somewhere that cooking with too high heat will oxidize the fat therefore making it dangerous/unhealthy to eat. what i’m trying to determine once & for all is, is it ok to cook the bacon at a lower temp(say 250) for a longer time(say 30min) to achieve a well-done state, or is that also dangerous since it’s still being cooked to well-done ? Thanx in advance for any input & advice on this !

    Peter Fitzwell wrote on May 30th, 2016

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