Keep Sauces Tasting Their Freshest
To keep your tomato-based sauces tasting their absolute freshest, here are some sound, generally accepted commercial food handling procedures to follow! (After all, an ounce of prevention is worth a pound of cure!)
Buy High-Quality Seasonings/Ingredients:
Lower-quality and/or untreated seasonings almost invariably increase the chances of your sauce "prematurely aging," thereby creating "off" flavors and eventual spoilage. (To better understand what can cause a sauce to prematurely age, click here.)
High-quality seasonings that have been properly treated by their manufacturer are significantly less likely to cause premature sauce aging. However, to further decrease the risk, a good practice is to sterilize seasonings by sautéing them in oil (or boiling them in water) just prior to adding them to your tomato-based sauce.
Cool Sauces as Rapidly as Possible:
Under warm temperature, sauce-aging microbes multiply quickly—at logarithmic rates! Therefore, it's important to cool stored sauces as quickly as possible. Also, storing sauces in smaller vs. larger containers accelerates refrigerator cooling at the "core" of the container.
Keep Your Sauce Refrigerated:
As is true for most foods, microbes capable of aging a sauce grow fastest in a warm temperature environment (60°-110°F.) Therefore, after mixing in the other ingredients, promptly refrigerate tomato sauces (35°-40°F), preferably in lidded containers, prior to subsequent heating/usage.
Avoid the "Sourdough Starter" Syndrome:
It's possible to "reinoculate" new, previously "sterile" sauce batches by combining old and new sauces and/or by not sanitizing storage containers between batches. (Because their surfaces are porous, plastic containers are particularly vulnerable to "reinoculation.") Similarly, make sure the mixing/ladling utensils used are also well sanitized.
Avoid Aluminum and Plastic Containers:
In choosing storage containers, select stainless steel over plastic or aluminum. The problem with plastic is that its surface is easily nicked, leaving small crevices which can eventually harbor "souring" microbes. The problem with aluminum is that it imparts a bitter, metallic flavor to tomato-based sauces in reaction to the tomatoes' naturally mild acidity.