Why Preserve Foods?
There are many reasons – save the harvest from our garden for later in the year, control the ingredients that go into our food, nostalgia (memories of our parents or grandparents), make gifts, satisfaction of making it yourself… etc. For me, it’s curiosity, controlling what I eat and just the satisfaction of making it myself.
There are many reasons – save the harvest from our garden for later in the year, control the ingredients that go into our food, nostalgia (memories of our parents or grandparents), make gifts, satisfaction of making it yourself… etc. For me, it’s curiosity, controlling what I eat and just the satisfaction of making it myself.
Why foods go bad?
Before we start preserving foods, we need to know why foods spoil.
Before we start preserving foods, we need to know why foods spoil.
The two main culprits are
1) The obvious culprit is bacteria, molds and yeast/fungi. I call them “bad bugs.” There are “good bugs” that help with fermentation (yogurt, beer, wine, sourdough breads and pickles), but the bad bugs rots foods, gives foods an off taste and can make us sick.
2) The other culprit is enzymes. Enzymes are molecules that occur naturally in food which encourage chemical changes, some of which are desirable - help ripen fruit by converting starch to sugar, soften fruits or vegetables, or reduce acidity level. Some changes are not desirable, browning when an apple is cut, or the fruit becomes overripe where the flesh becomes soft and mushy.
1) The obvious culprit is bacteria, molds and yeast/fungi. I call them “bad bugs.” There are “good bugs” that help with fermentation (yogurt, beer, wine, sourdough breads and pickles), but the bad bugs rots foods, gives foods an off taste and can make us sick.
2) The other culprit is enzymes. Enzymes are molecules that occur naturally in food which encourage chemical changes, some of which are desirable - help ripen fruit by converting starch to sugar, soften fruits or vegetables, or reduce acidity level. Some changes are not desirable, browning when an apple is cut, or the fruit becomes overripe where the flesh becomes soft and mushy.
The other supporting culprits are oxygen and unintentional moisture loss. Fortunately, when we eliminate microorganisms, the rest of the culprits are taken care off at the same time.
Good bugs and bad bugs keep growing and growing?
Bacteria, molds and yeast are living organisms that are present at all times – in the air, on surfaces, and on our food. In order for organisms to survive, they need food, water, oxygen (although some microorganisms can survive without oxygen) and a comfy environment.
Bacteria, molds and yeast are living organisms that are present at all times – in the air, on surfaces, and on our food. In order for organisms to survive, they need food, water, oxygen (although some microorganisms can survive without oxygen) and a comfy environment.
A better way to remember food, water, oxygen and comfy place to live is by remembering “FATTOM” or “FAT TOM”. No, FATTOM is not the guitar riff to “Smoke on the Water” [F-A-T, T-T, O-M; F-A-Tee-Tee-O-M].
FAT TOM represents the six conditions microorganisms need to grow/multiply.
FAT TOM represents the six conditions microorganisms need to grow/multiply.
FAT TOM is Food, Acidity, Temperature, Time, Oxygen and Moisture.
* Food - Microorganisms, like people, need nutrients. Unfortunately, that means microorganism eat what we eat. Some microorganisms can get by with sugar while other need protein. The foods of concern from a food safety standpoint are low acid, protein rich foods, such as, meat, dairy and egg containing foods.
* Food - Microorganisms, like people, need nutrients. Unfortunately, that means microorganism eat what we eat. Some microorganisms can get by with sugar while other need protein. The foods of concern from a food safety standpoint are low acid, protein rich foods, such as, meat, dairy and egg containing foods.
* Acidity – Acidity is a value between 0 to 14 (known as pH) where values less than 7 are acidic and values above 7 are alkaline. For example, water is generally neutral at pH = 7 while vinegar is acidic with a pH between 2.4 and 3.4. Most foods we eat have a neutral to acidic pH where foods with values 4.6 or higher are considered low acid foods.
* Temperature – Temperatures between 40F (4.4C) to 140F (60C) is considered the Temperature Danger Zone (TDZ) where microorganisms can grow. The optimal temperature for growth is typically between 70F (21C) to 100F (38C). Note: In the USA, the FDA is lowering the higher temperature from 140F to 135F (57C).
- Food Safety Tip: Hot foods should stay hot, above 140F (60C). Cold foods should stay cold, below 40F (4.4 C)
* Time – Given the right conditions and temperatures 40F to 140F, microorganisms start growing. Given enough time, the population will grow rapidly to levels that can make us sick.
- Food Safety Tip: Two hour rule and the Four hour rule.
Foods kept at room temperature (in the TDZ) should be refrigerated before two hours. Foods are to be thrown out after 4 hours in the TDZ. For hot days, for example a 90F (32C) day, the time is cut in half.
Foods kept at room temperature (in the TDZ) should be refrigerated before two hours. Foods are to be thrown out after 4 hours in the TDZ. For hot days, for example a 90F (32C) day, the time is cut in half.
- Food Safety Tip: Also, cooling foods in the refrigerator, foods should be cooled within two hours (from 140F (60C) to 70F (21C)). Of course, faster is better. For example, a pot of chili beans can be cooled quickly by pouring into a baking dish where the chili beans are spread out into a thin layer.
* Oxygen – Most microorganisms need air. There are a couple bad bugs that don’t need air to grow where Clostridium botulinum (Botulism), being the most notorious bad bug that prefers a no oxygen environment.
* Moisture – Pure water is the key to life while salt water is less desirable.
How does knowing FAT TOM help us preserve food?
Food preservation works by changing the condition of our food to discourage bad bug growth. Food is what we are trying to save and Time is beyond our control. The remaining factors we can change areAcidity, Temperature, Oxygen and Moisture.
Food preservation works by changing the condition of our food to discourage bad bug growth. Food is what we are trying to save and Time is beyond our control. The remaining factors we can change areAcidity, Temperature, Oxygen and Moisture.
Brief summary of how each food preservation method works. | ||||
Preservation Method | Acid | Temperature | Oxygen | Moisture |
Freezing | Storing foods at 0F (-17.8C) or lower | Airtight packaging | ||
Boiling Water Canner (high acid foods)/Pressure Canner (low acid ) | Some foods can be acidified using vinegar or lemon juice | Heats foods to kill bad bugs and neutralize enzymes | Jars form a vacuum seal – creates a low oxygen environment | |
Pickling and Fermentation | Food is acidified by using vinegar or natural bacteria creating lactic acid | Brines (salted water) and sugars reduce fresh water | ||
Drying | Airtight packaging | Removes up to 90% of the moisture | ||
Jam and Jellies | Vinegar or Lemon juice, Fruits naturally acidic | Cooking, canning or Freezing | Canning will create a vacuum seal | Sugar reduces water available |
Maple Apple-Pear Butter
Adapted from the 2009 Oct/Nov issue of Fine Cooking
3 1/2 lb ripe pears (I used Bosc)
2 1/2 lb apples (I used Paula Reds)
3 c. apple or pear cider
1 c. maple syrup
1/4 c. dark brown sugar
1 1/2 tsp. ground cinnamon
1/4 tsp. ground cloves
1/4 tsp. salt
1 T. lemon juice
1 1/2 tsp. vanilla extract
Cut the pears into 1-inch chunks. Cut the apples in half or into quarters if large. Put the fruit and the cider in a very large pot (at least 7-qt). Bring to a boil over high heat. Reduce the heat to medium low and simmer, stirring frequently, until the fruit is very soft when pierced with a knife, 40-60 minutes. Take the pot off the heat.
Set a food mill fitted with a fine sieve disk over a large bowl (or use a mesh sieve and a soup ladle to mush the mix through into a large bowl). Puree the fruit in small batches, discarding seeds and skins.
Wipe out any remaining seeds or peels from the pot and pour in the puree. Add the maple syrup, brown sugar, cinnamon, cloves and salt. Stir until well blended.
Bring to a boil over high heat. Reduce the heat to low or medium low to maintain a simmer. Using a large spoon, skim off most of the foam that rises to the surface during initial simmering.
Continue simmering, stirring often with an angled spatula, making sure to scrape the bottom, corners, and sides of the pot, until the puree becomes thick and dark and the bubbling becomes slow and laborious (like volcanic burps), 1 3/4 hours to 2 3/4 hours (yeah, I know)... Be sure to stir toward the end of cooking to avoid scorching. To test for doneness, spoon a dollop of the butter onto a small plate and refrigerate for a minute or two. It should hold its shape with no water separating out around its edge.
Remove the pot from the heat and add the lemon juice and vanilla, stirring until well blended. Transfer the butter to a container, let cool to room temperature, and then store, covered in the refrigerator for up to 3 weeks; or freeze for up to 1 year.
It's 9:30 and I have completely finished the butter - taste tested and all. After three battle wounds and three hours, it's some pretty awesome stuff. Sweet and comforting. I put the finished product in a jar for photo purposes, but will be dumping the extra into a ziplock and saving for Christmas-time.
2 comments:
You did a great job with the Daring Cook challenge. Kudos. This is my first visit to your blog but I suspect I'll be back often. I found you via the FoodBuzz Project Food Blog competition. I really like the food and recipes you feature here. I'm looking forward to seeing what you plan to do in the next leg of the competition. I wish you lots of luck. Have a great evening. Blessings...Mary
September 14, 2010 at 11:33 PMThank you Mary! I had a chance to check out your blog - BEAUTIFUL! I love your photos and will definitely be checking your site out for photo tips. Thanks for the follow and best wishes - same to you!
September 15, 2010 at 7:21 PM-Alise
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