Thursday, July 14, 2011

In a Pickle

I was out of town last week, and I came home to cucumber vines loaded with over-sized cukes.  I picked every little baby cucumber before I left, and still they exploded with fruit in five days.  There was nothing to do but pickle them. 

Kirby Cucumber
I have always pickled my cucumbers by adding vinegar, salt and spices and then processing the jars in a water bath to sterilize the pickles.  Since pickles are acidic (from the vinegar), it's easy to home-can them without a pressure cooker, as they don't need to be heated above boiling.  I always use Kirby cukes, since they are crisper.  They have tiny spines on them, but I just rub them off with my hands, cut off the ends and cut the cukes into long spears.  I remove the seed core as I cut - it just makes better pickles that way.

This year, I had no time to home-can when the cukes were ready.  My cucumbers had to do the work themselves.  I found a recipe for fermented Kosher cukes, and went to town.  Home-fermented cukes don't use vinegar - they make it!  There are bacteria and yeast naturally found on the cucumbers, the spices, the dill, and if you give those little critters the right conditions, they will turn cucumbers into great pickles.  Here is a jar of cucumbers in the process of becoming pickles.  You can see the dill and spices I added.

New pickles plus dill, coriander, mustard seeds, pepper, garlic and more.
Here's how fermentation works.  There is an enormous variety of bacteria, yeast and fungi on every surface around you, including you.  Those microbes are all either actively eating whatever they are growing on, or they are waiting come into contact with something that is food.  Microbes use food resources in a variety of ways, all producing energy, but usually producing interesting byproducts too. The process of microbes breaking down food (usually without oxygen) and producing byproducts is called fermentation.  Some microbes break down perfectly good produce for food, leaving behind bubbles of carbon dioxide and a watery mess.  Incidentally, this is also what we produce when we break down food for energy!  When you see a rotten spot on a tomato, you know one variety of microbe has won a battle and is taking over.  When oxygen is absent, other bacteria can break down the produce and leave behind methane or botulism toxin.  Others produce a variety of acids, and these are the ones we're using for pickling. 

Acid-producing bacteria grow well with a limited amount of oxygen, and many of them are salt-tolerant.  Most disease-causing bacteria are not salt-tolerant.  If you give them a food source, such as a fresh cucumber, and eliminate competing microbes by keeping out most oxygen and adding salt, the little acid bacteria can go nuts.  They break down the sugars in the cucumber and release lactic acid and acetic acid, which tastes sour and helps keep even more harmful bacteria out of the food.  It is not a coincidence that vinegar is acetic acid.  In fact, vinegar is produced by a similar process as my home pickles, but using apple cider, wine or some other food source for the bacteria. Other sour-tasting foods are produced by a similar process, for example yogurt and kim-chee. 

Once a food has been fermented, the acid adds extra protection against spoilage by non-desirable microbes.  Before refrigeration and easy inter-continental transportation, pickling food was a major way of having food in the winter.  All kinds of things can be pickled: green beans, okra, hot peppers, eggs (they're good!), carrots, garlic and more.

After two days, my cucumbers are pickling away.  There is a little foam on the top of the pickle jars, and the liquid is becoming predictably cloudy.  I'm going to taste them each day, provided they look and smell like I expect them to, and when they are sour enough to my taste, I'll seal the jars and refrigerate them.  They should theoretically keep a long time if we don't eat them, and I could can them to make them last even longer.  Since canning involves heating them in boiling water to the point of sterilization (about 20 minutes, depending), the cucumbers will be less crunchy. 
Active fermentation going on here.
A little reassurance for the germ-phobes out there:  the microbes that live on you are mostly helpful.  They compete with disease organisms, they help digest your food, and they help keep your immune system working well.  A good variety of microbes is a great asset to your health.  If you add everything up, our bodies contain way more non-human cells than they do human cells.  The microbes in fermented pickles are good for you.  Yes, a stray bacterium can get into the batch and spoil things, so you have to watch out for contamination.  Remember, if it looks like a pickle and it smells like a pickle, it is probably a pickle.

1 comment:

  1. Here's an update on the pickle-making process. If you try these pickles, make sure the brine is way up over the tops of the cucumber spears. You may want to save a little extra brine to add to the pickles. You'll want to skim off any mold or bacteria that grows at the top of the jar. Mold is normal, and the extra brine keeps the mold away from the pickles. As always with pickles, if it smells or looks or tastes funny, you don't need to eat it. After using this recipe, I think it's easier to make a big batch in a gallon jar.