Pique the Geek 20091018. The Things that we Eat. Dried Foods

(11 am. – promoted by ek hornbeck)

Preserving food by drying it is prehistoric.  Humans have dried food for millenia, and it works as well now as it did way back when.  In this sense, I am not talking about grains and seeds that naturally dry on the plant, with no interaction from humans, but rather foods that need a bit of help to dry without going bad.

Let us take, for example, apples.  Dried apples are wonderful, but leave that apple of the tree and it falls to the ground, and just rots.  Apples are too moist in their prime state to dry whole, especially if nature is all that is working for one.

Enter mankind to make a better process.  We have learnt to peel and slice the apples, and then put them into a place where the water is lost rather quickly, before bacteria and molds can grow.  Please read further.

Before we get started, I just want to say that the media frenzy over the “Balloon Boy” story keeps getting one thing wrong:  Richard Henne claims to be a scientist.  Nothing could be further from the truth.  Scientists try their hardest to seek the truth.  Richard Heene does just the opposite:  he tried his hardest to pass what he knew to be false as the truth.  He is a charlatan, a liar, and apparently a thief.  He is no scientist.  He only claims to be a scientist, when in reality he is a crook.  Now, on the the matter at hand.

Fruit is relatively easy to preserve by drying because of three factors.  First, most fruits are low in fat, and fatty foods are difficult to preserve by drying because of reaction with atmospheric oxygen, which causes the fats to become rancid because of oxidation.  Second, many fruits are replete with antioxidants, which help to protect them from oxygen (however, this is weak in light colored fruits).  Third, most fruits are rich in sugar which, when combined with a low water content, protects them from bacteria (at around 25% to 30% water content or lower) and molds (at around 10% or so water content).  Very dry fruit keeps for years, but the more popular, lightly dried ones eaten today have a more limited shelf life.

Dried dates and figs are known from antiquity, and samples have even been found in tombs that have enough DNA to identify.  Most of them are hardly thought of as palatable, but after 2000 years a DNA identification is good enough for me.  Both of those fruits are high in natural sugar, and the hot geographical areas in which they traditionally grow make it easy to put them, whole, in the sun and allow the heat and low humidity air dry them naturally in a few days or weeks, and then they can be kept for many months if kept dry.  I love both of them, just eaten in the dried state.  But there are many more.

Drying, or dehydration, is easy to understand.  One just takes the fruit, puts it in a hot and dry place, and lets nature take its course.  It is important to get a jump on bacteria and mold before the fruit dries very much, many times the fruit was heated enough to kill or retard the microbes.  Then they were spread on rocks to dry.  Sunlight helps as well, since the ultraviolet light kills bacteria and molds.

Freeze drying, often thought of as a modern art, is actually prehistoric as well.  The ancient inhabitants of the very cold, dry, and elevated areas of what is now Chile and Peru used to take what are the ancestors of our potatoes and stomp them to a pulp, then spread that pulp onto clean rock in the rarefied atmosphere.  During the evenings, the food would freeze, and the low atmospheric pressure would cause ice to convert from solid to gas (a process called sublimation), and then the next morning, after the thaw, they would stomp the pulp well again to mix it.  After several cycles, a freeze dried potato would result (flavored with the heat of the day and the sweat from the feet of the people) that would keep for a long time, just needing to be reconstituted with water and cooked.  I suspect that it did not taste any worse than modern, cheap dehydrated potatoes.

Freeze drying these days involves taking any given food down to around the dry ice temperature (about -78 degrees F) and pumping as much air as possible away.  At those temperatures, water is very volatile compared to many scent and flavor materials, so the food becomes concentrated in everything but water, for the most part.  Delicate herbs are very well preserved this way, as are backpacker’s meals.  However, it is a relatively expensive process.  Almost any food can be preserved by freeze drying, and when rehydrated that steak that weighs only two ounces can be almost a pound of raw meat.  As an aside, there are several services who will freeze dry one’s dead pet and then coat it with a lacquer that prevents it from absorbing water from the atmosphere, so that the pet can “sit” forever.  It reminds me of the old Soap comedy where Jessica’s father, the Major, would “walk the dog” which was stuffed.  That was a really good and funny show, but it did not pass the test of time.

For those of us who have neither a vacuum pump nor a source of dry ice, we can still dry food.  I am drying apples right now, and will show some pictures later.  Dried fruit is easy to make, and is EXPENSIVE to buy, so make your own.  If you are not fortunate enough to have a food dehydrator, a slow oven will work well, and some fiberglass screening and the sun and wind is even better.  I will use apples as an example, but most other fruits can be dried in a similar manner.  I will get to meats later, because they are more demanding.

I took a bunch (a quarter bushel) of apples and peeled them.  Now, this is extremely important, and do not forget it.  Apples, and other light colored fruit, will discolor on contact with air and soften.  Even dark colored fruit will soften and decay, so read well.  You must protect the fruit from oxygen.  The old method was to immerse peeled or sliced fruit in salt water, but that ruins the juice for anything else.  The best way is to take two, 500 mg Vitamin C tablets and grind them up and add that to the water in which one immerses the fruit.  That way, good jelly and fruit butter can be made without a salty taste.

This brings to mind a commercial product called Fruit Fresh.  It is mostly sugar with a little Vitamin C in it.  You can buy a lifetime supply of Vitamin C tablets for one season’s worth of Fruit Fresh.  Just take 2, 500 mg tablets of Vitamin C, crush them up, dissolve them in up to a gallon of water, and put into a plastic, glass, or stainless steel container and add the fruit.  The only essential thing is to be sure that every cut surface of the fruit is exposed to the Vitamin C.  You do not have to keep it submerged all the time.  Vitamin C tablets cost less than 1% of Fruit Fresh, and works as well or better.  The essential thing to remember is that as soon as the fruit is exposed to the air, roll it in the solution.

Later will appear a picture of my apples, some after two hours, in the Vitamin C solution.  Those same apples would be dark brown if left out on the counter.  It is a wonder substance.  It also makes the mix more acidic, which is a good thing if you want to make jelly or butter out of the leftovers.

I took the slices and put them on the trays of my ancient dehydrator, and they are drying nicely.  They are still nice a pale, thanks to the Vitamin C.  Tomorrow they will be dry enough to enjoy, but to preserve them without refrigeration will require that I make them uncomfortably dry to the tooth.  I can do that, but I prefer them with a bit more moisture.  If I were to dry them to under 10% water content, they would keep at room temperature for over a year, but they are too tough to be a nice snack.

As I said, fruit is pretty easy to preserve because it has lots of sugar in it, and sugar, at over 65% (like in jam and jelly) prevents almost all bacteria from attacking the food.  Molds can still go for it, but jelly and jam, kept in the refrigerator after opening, rarely gets moldy if one eats a serving or two every week.  Since I live alone, I put my jelly up in half pint jars, which is about as much as I can eat before it goes bad.  For folks with two or more household members, pints are fine.

Meat is much harder to preserve, because it has hardly any sugar in it and is a wonderful medium for bacteria.  It is also often full of fat, and fat does not dry well without other treatment.  Jerky is the most famous dried meat product, so I will describe how to make it here.

First, take the most lean cuts of meat that you can find.  Rump roast makes good jerky, and so does very lean round steak.  Just cut off all of the fat that you can see.  The fat makes it go bad.  It is possible to preserve fatty meats, and actually wonderful, but that is sausage, not jerky.  I will speak about sausage later in the subtopic of fermented foods.

To make jerky, cut very lean meat into strips not more than 1/4 of an inch thick.  It is easier to do that if you put the meat into the freezer until it gets about half frozen, so that it keeps the shape.  Work fast.  As you cut the meat, put it into a marinade with quite a bit of salt.  Soy sauce works well, but if you do not like that flavor, heavily salted water is fine.  Meat, being essentially without sugar, needs salt to preserve it in addition to drying.  You can add sugar to the brine for flavor if you like, and it helps to preserve it.

I like to take white vinegar and water, half and half, then add a tablespoon of salt per pint, and then add a little white sugar just for taste.  Then I add a bit of liquid smoke extract, some cayenne pepper, and a bay leaf or two, mix all of it together, and let the meat stand in this mixture in the refrigerator overnight.  Then I take out the strips and let them drip dry for half an hour or so.  I put them in the dehydrator, but you can put them in the oven, set very low, for a few hours.  Use a cake rack to allow hot air to come all over it.

After overnight, taste it.  If it is still soft, keep drying it.  It needs to be hard to be preserved.  If you have some thick pieces, just eat them now and allow the thin ones to dry well.

Since this is not a highly salted, nor treated with nitrate nor nitrite, you should keep it frozen or refrigerated.  These are not “hard” cures, but rather ones to enhance flavor.  The hard cures are just more of the same, and dried to 10% water or so.  Those have to be rinsed to remove some of the salt before you eat them.  If you want to keep a pink color, use Morton Tender Quick instead of the salt and sugar.  This product has nitrite in it and reacts with the iron in the myoglobin (the predominant protein in muscle) to prevent it from discoloring.

Another interesting dehydrated product that you can make is fruit leather, similar to the product called Fruit Roll-Ups in supermarkets.  Just simmer your fruit until soft in very little water (do not forget to add Vitamin C), strain off the juice (it is good to drink or for jelly), and run the fruit through a sieve to remove skins and seeds.  Add however much sugar you want and cook until it is thick (see later in the section about apple butter).  If it is chunky, run it through the blender.  My dehydrator has plastic inserts with no holes that fit on the racks so the thick mixture can be spread over it.  If you do not have those inserts, a couple of layers of polyethylene food wrap will do, or if you are using a slow oven just line a cookie sheet with the wrap.  When ready it will be leathery.  It is convenient to roll it with the plastic wrap on it so the layers do not grow back together.  Store in the refrigerator, since if you get it dry enough to keep it gets very tough.

Peppers and onions dry very well.  I dry cayenne peppers whole, and chop up bell peppers first, as do I do onions.  They are excellent for cooking, and if you get the starting material in season, you can have a whole year’s worth of dried peppers and onions for only a couple of dollars.  If you look at the prices for the commercial products, you will find that you are saving a lot of money.

Some things do not dry well.  As I said, fatty meats dry poorly (thy dry fine, just do not keep for long before becoming rancid).  Tomatoes are pretty watery to dry, and I prefer canned ones for most things anyway, so I do not bother.

One very positive aspect to drying food is that the bane of home food preservation, botulism, is prevented since the bacteria need moisture to grow and also are poisoned by oxygen.  However, there is one caveat:  NEVER put dried herbs and spices in oil for more than a day or two.  The residual water in them offer enough for the bacteria, and covering them with oil prevents oxygen from keeping the bacteria from growing.

I promised a commenter last week to describe the way to make apple butter, so here it is along with the directions for dried apples.

First, wash the apples carefully, since you will be using the peels for jelly perhaps.  Prepare two large glass, plastic, or stainless steel bowls by putting in a couple of quarts of water and two 500 mg Vitamin C tablets, crushed and dissolved.  If you are making butter and/or jelly, remove the stem because it makes the pulp hard to sieve.  Peel the apples, letting the parings drop into one bowl.  Once it is peeled, drop it into the other bowl and spin it to coat the entire surface with Vitamin C.  Make sure that the entire paring gets treated as well.

Stem removal

Here are the bowls and tools for processing apples.  I use a potato peeler to pare the apples and remove the cores, a knife for slicing them, and an old tablet bottle, cut off and sharpened to core the slices.

Parings in the Vitamin C solution

Peeled apple in the Vitamin C solution

You can slice the apples now or wait, depending on your personal preference.  I typically peel six or so, then slice them, dropping the slices directly in the Vitamin C solution.  Then I core them, dropping the cores in the solution with the parings and the cored slices back into the other vessel.  When I get what I think is one or two dehydrator trays full, I load them and recommence peeling until I am done.

Sliced apples in the Vitamin C solution

Parings and cores in the Vitamin C solution

Cored slices in the Vitamin C solution.  Some always break, but they still are fine.

Rings and pieces on dehydrator tray

I set the dehydrator to 155 degrees and start it (I kept it in my bedroom, since I keep my house at 60 degrees F and it has been very cool here, so the extra warmth was welcome).  On my particular design of dehydrator, all eight trays have to be in place for proper air circulation, even it they are empty.  Other designs vary.  It took about 36 hours to get these apples dry enough to keep without refrigeration.  Note how light colored they are.  Most commercial dried fruit is decolorized by sulfur dioxide treatment, but the Vitamin C did the trick for me.  Some people, especially those with asthma, are very sensitive to sulfur dioxide (also known as sulfites), so I can give these dried apples to anyone and be confident that no one will get an asthma attack from them.

Fully stacked dehydrator

Now, back to the parings and cores.  Notice how nice the color is, again because of the Vitamin C.  I take them and cover them with the water in which there were soaking, to keep on using the Vitamin C.  The water here in the Bluegrass is very hard with calcium, but that is good for both butter and jelly.  As a matter of fact, sugarless preserves are made with added calcium to fool the pectin into thinking that there is sugar in the mix, but that is for the What’s for Dinner installment that I am hosting on Halloween Night.  Cook the parings and cores until the cores are soft enough to run through the food mill, about three hours at a slow simmer.  If I were just using peels I would only simmer for about an hour, because pectin degrades with long boiling, but I wanted to use the cores too.

Cooked parings and cores

Let the cooked parings and cores cool enough to be easy to handle and then strain off the liquid into a plastic, glass, or stainless steel bowl.  I use a large kitchen strainer and a cloth baby diaper (bought especially for kitchen use, they have never been on a baby) to filter the liquid.  This is what I call Magic Juice, as it is concentrated pectin.  More on that Halloween.

Magic Juice

After the parings and cores are drained, I put them through the Foley Mill, but any kind of colander is fine.  The Foley Mill that I use is from my neighbors across the street, and it is a very old tinned cast iron and steel one.  The design is excellent, as it has a wedge shaped blade to push the pulp between the mating surfaces and a spring on the bottom to wipe the holes and thus direct the now deskinned and deseeded pulp into the catch vessel.

The Foley Mill

I keep saying to use glass, plastic, or stainless steel, and here is why.  Iron reacts with the tannins in the parings (and the tannins in other fruit as well) to produce a blue-green material that is unattractive.  This is, incidentally, the original source of blue-black writing ink.  Nut galls, growths on oak trees, are rich in tannins, and these were formerly collected and reacted with iron to form the ink pigment.  This is not any longer done.  The problem with this particular mill is that the tin plating has worn off over the 50 years or so of use, and bare iron is in contact with the food.  You have to work fast to keep it from discoloring.  I was recently at Ace Hardware, and lo and behold, the Foley Mill is still produced, but in stainless steel.  This is a much better material because the surface of stainless steel is coated with an extremely thin deposit of very hard and tough chromium oxide the renders is unreactive.  Likewise, never use cast iron to cook down juice or it will darken.  I use a nonstick coated aluminum pot, which is fine.  I do not recommend cooking acidic materials in uncoated aluminum at all.

Anyway, what is left is applesauce, if one adds sugar to taste.  To make butter, put into a heavy pan and add about half a cup of sugar per cup of pulp.  Heat to dissolve the sugar and then turn down as low as your range will allow.  On mine, if I keep the setting at the absolute minimum, I do not have to stand and stir constantly.  Otherwise the butter “plops” and sticks and burns on the bottom.  I cooked mine down for about four hours, stirring every 15 minutes or so.  About an hour before it was ready, I added two teaspoons of cinnamon, 1/4 teaspoons each of nutmeg and allspice, and kept cooking until I got a positive butter test using a cold plate.  Because the material is so thick, a cooking thermometer is useless to determine when it is ready to can, unlike jams and jellies.  To conduct the cold plate test, put about half a teaspoon of mix on a cold plate, put the plate back in the refrigerator for about 15 minutes, and look to see if any liquid separates.  If it does, keep cooking.  I tried to take pictures, but there was not enough detail for you to tell anything.  If no liquid separates and a peak will hold, the butter is ready.

Unreduced butter, aka applesauce

Butter ready to can.  Note the wooden spoon with a hole.  It is extremely useful for canning.

Now is has to be canned.  I never process jellies or jams, but because it is not possible to get a thick butter uniformly hot, processing is essential to keep it from molding.  Sterilize your jars (I used one pint Mason ones) with detergent and extremely hot water.  (A dishwasher using a heated dry setting works, too, but be sure that you do are not using a rinsing aid, like Jet Dry).  Jellies, jams, and preserves require dry jars, so I put them in a 180 degree oven, inverted, until I fill them.  That does not sterilize them, but it dries jars that are already sterile.  The lids and bands go into a saucepan and are brought to the simmer (NOT the boil) and held in the water until use.

Lids and bands on the simmer

At the same time, start heating up the water in the water bath processor.  Note that there is a perforated metal platform in the bottom of the processor.  This is necessary to keep bubbles from causing the jars from bumping into each other and possible breakage.  Once the jars are filled and the rims wiped (it is important to wipe the rims to make sure that no butter interferes with the seal), the lids are dropped on and then a band screwed onto the jar.  For jellies, jams, and butters, leave 1/4 inch headspace since the product is already cooked and will not change significantly in volume.  A little airspace is important, because liquid expansion will force butter into the sealing surface if the jar is completely full, and cause the lid to fail to seal.

Water bath processor with elevation rack in bottom

Empty jar with canning funnel.  That funnel belonged to my grandmum, who was born in 1903

Filled jar with 1/4 inch headspace and empty one ready to fill

Wiping the rims.  I use a paper towel just damp with water

Once the jars are filled and the bands screwed hand tight, put them into the processor, making sure that there is an inch or so of water above the tops of the jars.  It is helpful to keep extra hot water on hand to top off the processor if necessary.  I use the water in which the lids and bands were kept in for that.  Bring the water in the processor back to the boil, and then reduce the heat to a simmer.  Attach the lid and process for 10 minutes AFTER the popper starts venting.

Jar with lid

Jars in processor, note at least an inch of water above tops

The assembled water bath, my grandmum’s Grand Waterless Cooker

After the 10 minutes, remove the processor from the heat and remove the lid, taking care not to burn yourself with hot vapor.  Allow the jars to remain in the open processor, covered with water, for another five minutes, then remove them from the processor and place them on a insulated place free of drafts, until the lids seal.  You will hear a “ding” each time a lid seals.

The final product.  Note jar lifters, also from my grandmum

At that point, the bands should be removed and washed.  If you want to put them back on, wipe the thread area of the jars with a clean, damp washcloth and screw the clean and dry band back on the jars.  Unless I am traveling with canned food, I never put the bands back on them.  You are now finished, except for the cleanup step.

Well, you have done it again.  You have wasted another perfectly good batch of photons reading this drivel, but at least this time there are some pretty pictures.  And even though Richard Henne will confess that he is a faker when he reads me say this, I really to learn much more than I could ever hope to teach by posting this series, so keep those comments, questions, corrections, and other items of interest coming.  Remember, no scientific or technological issue is off topic here.

Warmest regards,

Doc

Crossposted at Dailykos.com