Last night we discussed the history of food preservation - for centuries people have salted, pickled and dried their food to make it last. Have you ever wondered how a dried out piece of salted cod could last so long without spoiling? Drying it out removes all the moisture in the fish – bacteria can’t grow because it requires a moist environment to survive.
This brings me to the topic of fat Tom – no, not my overweight friend, but an acronym. FATTOM reminds us what nasty microorganisms need to thrive and multiply. FATTOM is Food – bacteria needs food to survive; Acid – it also likes a certain pH balance, somewhere right in the middle. The two T’s are Time and Temperature – the longer food is left out and the temperature it remains at is very important hence, cooling large portions of food before placing in the refrigerator. O for oxygen, yes bacteria needs it too! Moisture is the last element as explained above in the dried fish example.
Pickling works because it is very acidic, too acidic for bacteria to grow. Legumes that have been dehydrated last a long time because moisture-loving microorganisms are kicked to the curb. Bacteria also have two other pals in the spoilage world – other microorganisms include yeast, and mold.
Let’s round out the general techniques of preserving food. We have dehydration, alcohol (primarily used for fruits - think pear brandy or eau de vie), sugar as in fruit preserves – the sugar slows down enzymatic activity, pickling, dry cure or salt, a liquid cure/brine (think of yummy salmon gravlax!), smoking (includes cold smoking, hot smoking and wood smoking), pasteurization, sterilization (think of grandma’s canned veggies or fruits), and some obvious ways are refrigeration/freezing (includes quick freezing & freeze drying), lastly, sealing & coating – on Friday night we are making duck confit – basically we dry cure the duck then ultimately cook it in rendered duck fat – the fat creates a barrier and microorganisms can’t get it to spoil that yummy goodness.
Along with this lesson, we made an Assortiment de Légumes à la Grecque that included artichokes, mushrooms, zucchini and cauliflower with a tomato fondue. À la Grecque is a method of preparation that involves cooking the vegetables and mushrooms separately in a mixture of wine, water, salt, lemon juice and olive oil. The result quite honestly did not wow me – but technique is what I am learning and that’s what’s important.
Lastly, I shot a candid of my stove away from home for friends to see what my station typically looks like. Imagine me here in my Chef-whites, learning, practicing and perfecting my craft.