A Friendly Guide to Bacteria

Look down, at your hand, at your keyboard, your fork, your cat, your lover’s eyeball…I really don’t care.  Just look at something.  Look closer.  No, closer.  You’re still not doing it, look, like, really really really close!  What do you see?

Honestly, probably not much unless you’re a sentient scanning electron microscope.  And if you are…can we hang out some time?

For the rest of biologics, we don’t have the built in equipment to see what I’m talking about: The Microbiome! (Cue that music from Jurassic Park). The microbiome is the unimaginably diverse ecosystem that exists all around you at the microscopic level.  This contains the single celled and some of the much smaller multicellular life of which there are all types.  Honestly, there is way more to microbiology than most of us think.

Now at the intersection of food and microbiology lives bacteria.  We spends our lives being conditioned to avoid and kill bacteria, but it is indeed an unsung hero without which there would be no life on Earth.  And that is no exaggeration, no bacteria, no life.  Even you, right now, contain a whole bacterial ecosystem in your digestive system (called your gut biota) that is working hard to ensure that you are able to get every last bit of nutrition that your lazy intestines left in the food you ate.  The link between a healthy gut biota and overall health and wellness is an exciting facet of medical research.  Just look up fecal transplants.  You won’t regret it.  Or you might.

So the point is, give bacteria a break, its doing its best. Now let’s talk about how to get rid of those disgusting little freeloaders.

So, although the vast majority of bacteria is not harmful, there is some that can make you sick or even kill you.  This is referred to as pathogenic bacteria.  When we cook, it is the pathogenic bacteria that we must be cautious of and when you food prep even more so.  Here is why.

When you get a foodborne illness, or food poisoning, that is of bacterial origin (food can make you sick by a variety of causes, bacteria is just the most common) you have typically consumed a lot of bacteria.  Sorry if that’s gross, but a single E. coli bacterium is probably not going to do much to you, but eating a whole colony just might. 

Let’s say that your kitchen is truly disgusting (this is hypothetical), you haven’t cleaned it since a year that began with 1.  You have named your Salmonella colony.  It’s name is Suzette, naturally.  Even in these conditions, if you cook a hot meal and eat it right away, your chances of getting intimate with Suzette are relatively low.  Still, don’t do this!

This is because bacteria do not reproduce instantaneously.  In our horrible scenario, you definitely ate some of Suzette, but only what could get onto the food since it finished cooking.  When keeping food safe, there are two main factors that must be controlled-time and temperature. 

Time:  Bacteria do not reproduce instantly- but they do reproduce pretty damn quick!  How quick?  In optimal conditions they can double their colony size every 20 minutes.  To really bring this into perspective, think of it in human terms.  Twenty minutes is approximately streaming an episode of a network sitcom.  So you sit down and watch an episode of The Office.  At the end of the episode you look to your left and there is another you!  For this bacterial analogy, yes, this must be an identical copy of yourself.  You and your new identical bestie watch another episode (that Dwight is such a menace!) and now, there are four of you!  Another episode (will Pam ever wake up and leave Roy!) and eight of you.  And so on and so forth.  After just two hours of binging, you would go from being so so alone, to sharing a couch with 64 identical copies of yourself (give or take a mutation or two).  

Bacteria accomplish this by their extremely efficient method of reproduction called binary fission.  For this, no dating required, just one bacterium copies it’s DNA and then splits in half to become two bacteria.  Those two repeat the process and again and again…every 20 minutes.  So you can see, you don’t need much bacteria to start a colony.  

The Other Stuff: Now I mentioned earlier, food safety is all about controlling time and temperature.  This is why.  Bacteria can double their colony size every 20 minutes in optimal conditions.  That means these pathogenic bacteria that may have gotten on your food need to have certain needs met in order to replicate so quickly, otherwise it is just a lonely bacterium.  We have an acronym for these needs FAT TOM.

Who is FAT TOM?  FAT TOM stands for food, acidity, time, temperature, oxygen and moisture.  When these things are in the optimal ranges, bacteria start multiplying.  Unfortunately, most of these needs you share with bacteria and therefore can’t eliminate.  For example, food is there, you can’t get rid of that and still work with food. 

Acidity refers to the pH range that bacteria prefer and it tends to be the pH of most food.  You really can’t change it without drastically changing your food.  Highly acidic foods, like ceviche, are out of the pH range of most bacteria which allow it to be safe to eat without cooking. 

Unless you’re food prepping on Mars, oxygen is present.  For your own livelihood you don’t want to change that.  Products like vacuum sealers can pull most of the oxygen out of a food product, effectively stopping bacterial growth, which is why vacuum sealing can help foods stay fresher longer.  

Finally, moisture.  Chances are you’ve never gotten food poisoning from plain crackers or beef jerky and that is because these are dry.  Bacteria need moisture to survive.  However, fresh food have moisture and we don’t want to change that!  Don’t dehydrate your pork chops! 

Instead of ruining our food by taking away the things that both bacteria and humans love, we control the temperature.  There is a temperature range called the temperature danger zone (DANGER ZONE!) that refers to the range of temperatures that bacteria thrive in.  This is from approximately 40 -140 degrees Fahrenheit.  Temperatures higher than that will kill bacteria, temperatures lower than that will drastically slow their reproduction, and temperatures below freezing will typically stop reproduction altogether.  But, be aware, cold temperatures don’t kill bacteria!  Once they warm up that can jump right back to life and reproduction.   

When it comes to food safety, the goal is to stay out of the temperature danger zone as much as possible.  The rule of thumb-food should not stay in the temperature danger zone for more than 2 hours (binging 6 episodes of The Office) and if the temperature is above 90 degrees no more than 1 hour (3 episodes of The Office).