I read the excellent article on by Dr. Steven Levy on the Patch earlier this week, and wanted to elaborate upon and clarify a few points he made, as well as offer some addition summer dinning tips.
There are six favorable conditions that allow food-borne pathogens to thrive. Those of us in the industry use the mnemonic "FAT TOM" to remember them:
Food: Bacteria and other pathogens need a growth medium, one rich in nutriments, in order to multiply. Most food contains enough of these nutriments for bacteria to live, but protein-rich foods like, meats, fish, dairy and eggs are a feast for these pathogens.
Acidity: Most pathogens in food require a slightly acidic or neutral environment in which to live, thriving in a ph level of 4.6 to 7.5.
Time: Once pathogens start to multiply, it doesn't take long for them to reach dangerous levels. Even an hour in the "Danger Zone" (cue Kenny Loggins!), 41F-140F, can render some food unsafe to eat.
Temperature: As noted above, the Danger Zone (still humming that song?) is where food-borne pathogens are able to reproduce, with their preferred temperature range being 70F to 120F.
Oxygen: Most (but not all) food-borne pathogens require oxygen to live.
Moisture: Water is essential for the reproduction of food-borne pathogens. The water activity level (the amount of water available to support reproduction of pathogens) is measured on a scale of 0.0 to 1.0, with levels under 0.7 usually being too low for most bacteria and fungi to grow. Fresh meat has a water activity level of 0.99.
Eliminating even one of these factors prevents the multiplication of food-borne pathogens. Keeping all this in mind, let's put this into planning our picnic!
If your event is on a hot day, eliminate those items which are obviously are going to be the most troublesome out in the heat. Salads made with eggs, mayonnaise and sour cream are going to spoil rapidly (as tasty as they are, Deviled Eggs are not a great picnic food). Steaks and chops are a better choice than hamburgers if you're packing a picnic. Because the meat is ground, there is less density than in a solid cut of meat and a hamburger will warm up faster throughout than, say, a steak (on the other hand, it also cooks faster). There is also more surface area for pathogens to attach themselves (ground meat is a prime vector for E.coli contamination - mostly due to the grinding process itself). I like to use marinades for meats that I plan to grill. Besides adding a level of flavor, a good alcohol, oil or vinegar-based marinade replaces some of the water in the meat, lowering its water activity level.
Another problem is the under-cooking of meat on the grill. Different meats require different temperatures to eliminate any possible pathogens it may contain.
According to the Pomperaug District Department of Health, foods should be cooked to these internal temperatures, measured at the thickest part:
- 165° Poultry, stuffing, stuffed meats and poultry, reheated foods
- 158° Ground beef, hamburgers, ground pork or lamb
- 145° Pork and pork products
- 145° Beef roasts, corned beef
Invest in a bi-metal thermometer (usually, less than $10) and cook all your food to the required temperatures. I like to fully cook chicken legs beforehand in the kitchen if I'm going to grill them, since they will take the longest time to cook on the grill. Make sure they reach the recommended temperature (165F) before serving. Frozen meat takes a long time to cook, so it's important to ensure that the center is cooked to the proper temperature. Just because it looks "done", doesn't necessarily mean that it's reached the correct temperature to render pathogens inactive.
One of the alternatives to scrapping the potato salad from your menu is to use a vinegar-based dressing instead of mayonnaise. There are many types of vinegars available, each adding a slightly different taste to your salad. You can even find flavored vinegars that can provide a touch of herbs or fruit to your salad. Even better is lemon juice, which is more acidic than vinegar, and better tasting, too! I use a Balsamic Vinegar glaze for grilled vegetables and some grilled meats, which is tastier than you'd think, and is a safer alternative to butter.
"Keep hot foods hot; keep cold foods cold" is another mantra we in the food industry use to remember how cooked foods should be treated before serving. A chafing tray is a good way to maintain the temperature of hot casseroles. While the Health Department only allows electric food warmers, you can still use Sterno-fired at home. Make sure you add enough boiling water (about a gallon per chafing pan) before placing the hot casserole in the tray. A chafing dish is not intended to reheat a cold casserole; it relies on the steam generated by the water in the pan to keep the food above warm.
While Dr. Levy suggests a holding temperature of 160F; the minimum required by the Pomperaug District Department of Health is 140F — I've found that the quality of food deteriorates fast at the higher temperature. The biggest mistakes people make with a chafing tray are not adding enough boiling water, using cold water instead of hot, using only one Sterno underneath (you really need two to keep the water very hot) and putting cold food above the boiling water, expecting it to heat up (the song for this section is "Hot, Hot, Hot!" by Arrow).
Casseroles should be stirred often, to equalize the temperature of the food. For vegetables and meats being held in a chafing dish, I suggest putting a little water or broth on the bottom of the pan to help distribute the heat and keep things moist. Add more as it evaporates.
The easiest solution for keeping cold foods cold is ice ("Cold as Ice", by Foreigner). Place a bowl of cold food inside a larger bowl filled with ice. You can also find inflatable table-sized ice baths at many outdoor shops which can hold several bowls. Make sure that the ice comes up to the level of the food within the bowl. You also need to stir the contents of the bowl from time to time to equalize the temperature of the food.
Whether it's cold or hot, try to avoid setting all the food out on a table at the beginning of the event. Wait until it's just about time to start eating to bring the food out of the refrigerator and oven. You also want to protect food from flying insects and debris. A layer of plastic film over cold food and aluminum foil on hot will do the job nicely.
Dr. Levy mentioned washing cutting boards between uses, which is a very good practice. However, the average household hot water heater doesn't do much to eliminate pathogens, although, most dishwashers now have a "booster" that brings the hot water up to sanitizing levels (171F). A good idea is to make a batch of liquid sanitizer (one-half tablespoon of unscented bleach to one gallon of water) and keep some in a spray bottle near your work counter. Once you wash your board in hot water, let it drain, spray it with the bleach solution, and let it air dry. This is also good for wiping counters and sanitizing utensils, especially when working with poultry items.
Because of the risk of cross contamination, it's a good idea to have several cutting boards for different uses - one for raw chicken, one for raw meats, one for everything else. In the industry, boards (and sometimes, knife handles) are color-coded for each use. In this case, yellow would be used for raw poultry, red for raw meats, and usually, white as a all-purpose board (although, technically, white is specified for dairy products).
Get a good quality NSF-endorsed board. These are made from polyethylene plastic and will last a very long time if you take care of it. Wooden cutting boards are not recommended (no matter how nice looking they are) because they are porous and bacterial can get trapped within the wood. If you can't bear to get rid of that wooden board, you can get color-coded cutting mats in the kitchen section of many department stores and place them over your board.
Now that you know how to serve your food, here are some recipes you can try for your next event.
German Style Potato Salad
3 lb red bliss potatoes, thinly sliced
1/4 cup white sugar
1/4 cup white vinegar
1/4 cup salad oil
1 Tbsp celery or caraway seed
2 red onions, julienned
3 Tbsp flat-leaf (Italian) parsley, finely chopped
1/4 cup chopped crisp bacon (optional, for garnish)
2 Tbsp parsley, finely chopped (optional, for garnish)
Cook the potato slices until just done. Drain, and shock with cold water. While the potatoes are cooking, combine the sugar, vinegar, oil and celery seed. When the potatoes are cool, add them and the onions and parsley to the sugar mixture. Combine gently, but well. Season with salt and white pepper. Place in serving bowl, and garnish with bacon and parsley.
Asian-flavored Summer Slaw
1/4 cup turbano sugar
1/4 cup rice wine vinegar
1/4 cup vegetable oil
1 Tbsp finely minced fresh ginger
1 tsp soy sauce
1 tsp sesame oil
1 head savoy cabbage, finely shredded
1 carrot, finely shredded
10-12 Asian pea pods, julienned
Toasted (or black) sesame seeds (for garnish)
Mix the sugar, vinegar, oil, ginger and soy sauce and sesame oil in a non-reactive mixing bowl until the sugar is dissolved. Let sit for 1 hour to let flavors meld. Add the cabbage, carrots and pea pods and toss well. Allow to sit overnight and toss again before serving. Garnish with the sesame seeds.
2 cups canola or light vegetable oil
1 cup red wine vinegar
1/2 cup chopped fresh herbs of your choice
1 Tbsp kosher salt
Black pepper to taste (if desired)
Combine all ingredients in the jar of a blender, and whirl until smooth. Place your meat in a large zip-lock bag and pour the marinade over it. Seal the bag and place in the refrigerator for one hour per pound. Drain meat before grilling or barbecuing. Reserve the marinade for basing the meat during cooking. This should make enough for about five pounds of meat. Vary this recipe by using different kinds of vinegar, wine or anything that has a high acidic content (I've tried this with pickle juice, which resulted in a very different flavor). Remember, if you're substituting dried herbs for the fresh, you only need a third as much.
1 qt balsamic vinegar
1-3 Tbsp honey
Pour the balsamic vinegar into a non-reactive sauce pan and bring to a boil Continue boiling until it starts to thicken, stirring often to keep it from burning - the thicker it gets, the more you need to stir it, until you're stirring constantly. When thick and syrupy, remove from the heat and add the honey, to taste. Allow to cool and put into a squeeze bottle. Use over grilled meats or vegetables.