Sugar and Salt in Food Preservation

by Catherine Haug

During our discussion of topics for our upcoming event, Putting Food By Without Refrigeration, the question of salt was raised,

Salt is needed for so many of these processes; what will we do when we can no longer import salt from out of the area?

I ask our ESP community:  Are there any salt licks or other natural sources of salt in our valley?

And it’s not just salt, but also sugar that is used in preservation of foods; here are just a few uses:

  • Salt and sugar are both used for brining to preserve meat, whether or not the meat will also be smoked;
  • Salt is used for salt pickles;
  • Salt is used for sauerkraut and most lacto-fermentation preservation; techniques (pickled cucumbers, beets, peppers, beans, asparagus, olives, etc.);
  • Sugar is used for canning fruits.

Not to mention the seasoning and flavoring of foods and baked goods! Or providing salt for livestock….

Indeed, one can list the basics that are required for survival:

sunshine, food, water, salt, shelter, flint and sugar.

Using Salt and Sugar in Preservation

Salt

Common table salt, primarily sodium chloride (NaCl) is the most important ingredient for curing food.  At earlier times in history, salt was used as currency (He’s worth his weight in salt…).

Today, people avoid salt out of fear of hypertension and heart disease, but for most people, this should not be a concern, as only a minority of people are sensitive to salt in this way. [I believe highly processed foods are the greater culprit in these diseases].

We remember when Melanie showed us how to make sauerkraut last fall (Sauerkraut and Lacto-fermentation (10/22/08)), how much salt she used (3 tablespoons per 5 pounds of cabbage).  Yes, quite a lot of salt is required for preservation.

How does it work?

Salt kills and inhibits the growth of unwanted microbes, by drawing water out of the cells of the microbe and also the food, through osmosis.  According to Wikipedia:

Concentrations of salt up to 20% are required to kill most species of unwanted bacteria. Once properly salted, the food’s interior contains enough salt to exert osmotic pressures that prevent or retard the growth of many undesirable microbes.

Most commercial sources of salt are from salt water, such as the Great Salt Lake, or sheltered ocean areas.  But salt can also be found inland, far from salty seas, in what are called salt licks, places where wild animals come to lick the rocks for salt.  Per Wikipedia:

In an ecosystem, salt/mineral licks often occur naturally, providing the sodium, calcium, iron, phosphorus and zinc required in the springtime for bone, muscle and other growth in … wildlife, such as [deer], moose, elephants, cattle, woodchucks, domestic sheep, fox squirrels, mountain goats and porcupines. Harsh weather exposes salty mineral deposits that draw animals from miles away for a taste of needed nutrients.

Sugar

Sugar is also much maligned in today’s weight-conscious society, but it is a basic nutrient needed for energy production by plants and animals.  All plants use sugars (in the form of starches and fiber) to store the sun’s energy.

And mankind uses sugar not only to flavor, but also to cure food. Certain beneficial lacto-fermenting bacteria (such as the Lactobacillus family) feed off sugar in certain forms:  sucrose, glucose, fructose, and lactose, to ferment the food.

According to Wikipedia:

As the unwanted bacterial growth is delayed, the salt tolerant lactobacillus outcompetes them and further prevents their growth by generating an acidic environment (around 4.5 pH) through production of lactic acid. This inhibits the growth of other microbes and accounts for the tangy flavor of some cured products.

While vinegar (followed by canning) is often used instead of lacto-fermentation to preserve foods today, lacto-fermentation is far more healthful, because the food is preserved as a living food.

This fermentation of foods with the aid of sugar includes, but is not limited to:

  • mead, beer and wine (glucose, fructose and sucrose)
  • yogurt, kefir and cheese (mainly lactose)
  • pickled vegetables (glucose, fructose and sucrose)
  • olives
  • corned beef and other brined meats (glucose, fructose and sucrose)
  • real catsup and salsas (glucose, fructose and sucrose)

Many of these foods already contain the needed sugar in the raw food (honey, grain, grapes, milk, olives).  But what can we use as a source of sugar for curing of flavoring other foods, that can be produced here in the Flathead?

  • Honey is an obvious first answer, as long as the bees can survive colony collapse disorder;
  • Fruits can be concentrated into syrups to sweeten food;
  • Barley grows great here, and can be used to make barley malt syrup.

Can you think of others?

Smoke

From Wikipedia:

Smoking adds chemical compounds to the surface of an item which affect the ability of bacteria and fungi to grow, inhibit fat oxidation (and thus rancidity), and change flavor.

Often, food to be smoked is first soaked in a salt and sugar brine (to inhibit bacterial growth) with other ingredients added for flavor, then smoked to inhibit fat oxidation.  For example, refer to How to Smoke Salmon (on fishcooking.com).

Saltpeter

Saltpeter (Potassium nitrate) is often an added ingredient in food preservation, because it protects against botulism and certain other microbes. Originally (centuries ago), desert sea salt such as from the middle east was used to preserve foods.  This salt contained a minute amount of potassium nitrate, so was a very effective preservative.  With time, mankind learned to make the substance and add it to purified salt (not untreated sea salt), to ensure the safety of preserved foods.

In the 1970s, nitrites and nitrates in cured foods were implicated as cancerogenic factors, especially when the cured food is subjected to high cooking temperatures. It should not be a problem when the cured food is slow cooked (such as most recipes for corned beef, or braised sausage), or served cold (luncheon meats).

See The Health Effects of Nitrate, Nitrite, and N- Nitroso Compounds By Assembly of Life Sciences (U.S.). Committee on Nitrite and Alternative Curing Agents in Food for more.

But, where can we get saltpeter (naturally) here?  Again, I suspect it might be present in mineral salt licks…

Leave a Reply