Tuesday, February 23, 2016

Fermentation and Salt

 "Fermentation by definition is an anaerobic process. The lactic acid bacteria that carry out dairy and vegetable fermentations can grow in the presence of air but do not use oxygen to generate energy for growth. Using a fermentation lock to exclude oxygen but allow gas to escape will prevent aerobic yeasts and molds from growing. Aerobic yeasts and molds growing on the surface of sauerkraut brines can soften the kraut and produce off flavors. A more serious problem is that yeasts and molds growing aerobically on the surface of vegetable fermentation brines can consume the lactic acid and can cause pH to rise above 4.6, potentially resulting in botulism. Anaerobic fermentation of cabbage, on the other hand, with 2% salt (NaCl) and a temperature around 18C (64F) typically makes very good quality sauerkraut".  Dr. Fred Breidt, USDA, Microbiologist

Weight Matters
Salt is to brine, like flour is to a well-made bread.  Proportions matter, and in both cases, measuring spoons and cups are inadequate tools when it comes to obtaining the correct amount of dry ingredients.  Just like every type of grain has a different weight, every salt has a different weight depending on its grind, density and moisture content.  Salt, like flour, is a more reliable, consistent ingredient, when weighed - NOT measured.

To illustrate...Each dish in the above-photo contains 1 level-tablespoon of unrefined, additive-free (no added iodine or anti-caking agents) high-mineral salt, every one a unique brand and grind, ranging from super-fine to large and coarse. Several are moist, some are bone-dry. The brick-red Hawaiian salt (NOT meant to be used as a brine-salt, but instead, a "finishing" salt) contains added clay.  Using a digital scale, set to metric-grams instead U.S. ounces, we weighed each tablespoon of salt.

The end result:  Their weights ranged from 10 to 16-grams per tablespoon. That's a whopping 60% difference, negatively or positively impacting salinity!  Variations in salinity will impact fermentation.  

Salt helps lactic acid bacteria win the microbial race.  At a certain salt concentration, lactic acid bacteria grow more quickly than other microbes, and have a competitive advantage.

Below the correct concentration, bad bacteria may survive and spread more easily, possibly out-competing lactic acid bacteria and spoiling your pickles. Also, lactic acid bacteria don't survive in brines that are less than 1%.  The "no-salt" fermentation movement doesn't have its roots in traditional fermentation, but instead, in modern misunderstandings about the importance of salt.
Too much salt is also a problem.  Lactic acid bacteria cannot thrive, leaving your vegetables unpickled, and instead, salt-cured.  Salt-cured has always been a traditional method of fermentation, but it is intentional - meant to kill lactic acid bacteria.  What's more, salt-tolerant yeasts can spread more quickly.  By consuming lactic acid, yeasts make the pickles less acidic - and more hospitable to spoilage microbes.

Weigh, Don't Measure Salt

1. Use easy-to-read brine-tables - based on traditional formulas used by artisan butchers, cheese and pickle-makers.
2. Create the amount of brine you need, whether 1-cup, 1-gallon, or 1-liter, at the proper salinity-level, following our easy-to-read chart.
3.  Buy a gram-scale.  Digital scales are inexpensive - under $20 - readily available.  Make sure there's a "tare" button to zero-out your scale, to obtain the most accurate weight. Scales have a toggle-switch on the underside, one-side labeled "OZ", and the other, "GM". Switch the switch to GM - grams.

Which salt is best?

We recommend most dry salts - never wet.  Wet salts typically contain clay or dirt, providing coloration (grey, red, brown, etc.) but they also act as a "substrate", a surface on which mold grows.  Even when wet salts are baked at a very high temperature, in the hopes of killing mold, rsearch has shown that many mold spores survive.   Another issue, not talked about enough, is the lead-content of many northern salts.  All salts are graded, like a good wine, according to their quality and  use.  We prefer a gourmet-grade for any culinary use, including fermentation.  

2%?  3.5%? 5%? 10%? Which brine is best?

Dr. Fred Breidt, a USDA microbiologist and UNC microbiology professor is quoted in mainstream pro-fermentation articles, as saying that properly-made "lactic acid fermentation is SAFER than canned food".   Dr. Breidt enthusiastically suggested that we could reduce the amount of salt normally used in other methods.  Because our anaerobic-container suffocates oxygen-rich mold and yeast, the excess salt is NOT inhibit their growth.  "Anaerobic fermentation of cabbage, on the other hand, with 2% salt (NaCl) and a temperature around 18C (64F) typically makes very good quality sauerkraut."
Dr. Breidt's summary was: "Using the 2% with its anaerobic-conditions, would create a consistently good end-product with superior results in taste, flavor and color retention."

2% Salinity:  Carrot sticks, shreds, slices; broccoli, cauliflower, pearl onions, green beans (add grape leaves to preserve color), asparagus, green/red peppers de-seeded, parsnip, kohlrabi, Jerusalem artichoke, zucchini (whole), sliced radish, whole-small radish, whole green tomato, are but a few examples. Quick guide: Fill the Pickl-It with food (dice, chunk, whole, etc.) to 1-inch below the "shoulder".  Add 2% brine to the "shoulder" so your vegetables are covered with 1-inch of brine.
3.5% Salinity: Pickled cukes for pickling-varieties such as Kirby or Boston.  Fermented short-term (7-days on-counter, then 2 weeks in fridge) creates "half-sour" - still half-white, somewhat green inside.  More fermentation-time creates evenly-distributed green color and sublime flavor.

10% Salinity:  For those serious about brine-curing meat, crafting authentic feta-cheese, pepper-mashes, curing green olives, authentic fish-sauce, and shrimp-sauce.

Chart #1:  Water is U.S. Measurement, salt in grams.

Examples: To create 8-cups of brine at 2% salinity, use 38 grams of salt.  To create 3-cups of brine at a 2% salinity, add the amount of salt called for in the columns under 1-cup (5 grams) and 2-cups (10 grams) which equals 15-grams of salt. If creating a 1% brine, simply divide the 2% salt grams by 50%.  To make a 1% brine for 2-cups of water, use half of the 5-grams, ROUND DOWN to 2 grams.  


Adapted from http://www.pickl-it.com

Monday, February 22, 2016

Fermenting Vegetables

What makes vegetables ferment instead of rot?
First of all, fermented vegetables ferment instead of rot because of the natural beneficial microbes in them. The job of the cook is to give those beneficial microbes the best possible environment to thrive and multiply. At the same time the environment needs to discourage the bad microbes that cause rot from multiplying and overpowering the mixture. This is where the salt comes in. Salt inhibits the growth of microbes.
Food that is naturally high in moisture like finely cut cabbage requires less salt than food with a hard rind, like lemons, in order to discourage the bad microbes. Food that spoils faster, like herrings, require more salt than food that is slower to spoil, like beets.  Salt also causes osmosis — a transfer of juices from the vegetables that is replaced by brine, further inhibiting spoilage.

Let’s look at what actually goes on as vegetables ferment
When you start to ferment vegetables (or dough or fish) there are hundreds of different microbes on the surface that are vying for supremacy. Whether you end up with rotting food, mold, or a nicely fermented food, depends on encouraging the good microbes, while trying to crowd out the bad microbes. The good microbes thrive in an acidic environment while the bad microbes don’t. Some microbes need air to multiply while the good microbes need an anaerobic environment.
You want to begin with more of the good microbes and less of the bad. Always wash your vegetables under cold, running water before you prepare them for fermented vegetables. This washes off some of the undesirable microbes right at the beginning. Wash and sanitize knives, cutting boards, jars, and bowls before you begin to make your ferment.
Salt inhibits the growth of yeast and delays the bad microbes from reproducing and this is why salt is commonly used in fermented vegetables. Use kosher salt or sea salt rather than table salt (Iodized salt) because the addition of iodine, an antimicrobial, will inhibit the good microbes, too and discolour your vegetables.
Inoculating a jar of fermenting vegetables with the good microbes will encourage the good microbes to reproduce at a faster rate, crowding out the bad microbes.  This replaces some of the need for salt in your recipe.  If your recipe calls for 2 tbsp of salt per quart — if you innoculate your vegetables with good microbes you can use 2 tsp of salt instead.

The 3 stages of fermenting vegetables
What you’ll see
What’s happening inside the jar
Day 1 to 2
Fine bubbles begin to form which break the surface when a knife is inserted inside the jar
Coliform bacteria begin the fermentation process. As it grows the mixture becomes more acidic. 
Day 3 to 5
Large gaseous bubbles form inside the jar. The food is pushed up from the bottom against the weight.   Unweighted food is pushed above the brine. The jar liquid overflows through the airlock. 
The Leuconostoc bacteria are multiplying and continue lowering the pH in the vat. This crowds out the coliform bacteria.
Day 5 to 8
The bubbling slows down or stops. The vegetables fall down in the jar and the pressure stops building up. The ferment can be refrigerated. It will continue to develop while in storage.
The environment in the jar has become more acidic and the lacto-bacteria is thriving, while the other bacterium and yeasts are being crowded out. The lacto-bacteria are living and active inside the ferment.   The fermentation can be slowed by refrigerating the ferment. It can be eaten now or the flavours can continue to develop over months. The jar contents are preserved in the acidic environment of the jar. 

Adapted from http://joybileefarm.com
Image from http://www.amertha.com

Saturday, February 6, 2016

Steps to Making Kombucha

I have several friends and family members that want to make their own kombucha.  I made this quick list to help me and them remember the steps.  I also have them read the previous posts to this blog, giving them much more background than this list.

Kombucha Steps

1.        Boil 1 gallon of water for tea; boil for 20 minutes to rid of chlorine
2.       Let black tea brew 5-10 minutes, adding 1 cup sugar.
3.       Cover and let tea cool overnight.
4.       Pour tea into 1 gallon glass jar.  Add 1 cup of tea from SCOBY hotel and the SCOBY.  Wash your hands with vinegar before touching the SCOBY.
5.       Allow to ferment for 5-10 days, depending on temp.  Best between 75 and 85 degrees.
6.       When first ferment is tangy and sweet to taste, you are ready for second ferment.
7.       Put SCOBY in hotel with 1-2 cups of the fermented sweet tea.  Wash your hands with vinegar before touching the SCOBY.
8.       Put remaining fermented sweet tea in jars – 16 ounce or half gallon.  In jars, add fruit, ginger, fruit juice, etc. as desired.  Do NOT use cranberries.
9.       Second ferment will ferment for 3-5 days, depending on temp.  Best between 75 and 85 degrees.
10.   Put into bottles and put bottles in fridge. 
11.   Enjoy!