FAQs about Soft Cheeses--What's Safe, What Isn't

Soft cheeses are great, right?  The taste and texture are irresistible, the protein and calcium are healthful, and the cheeses are easy to smear on a cracker and pop into our mouths--over and over.  But soft cheese is also riskier, so it must be selected and handled carefully.   The FAQs that follow explain the dangers and offer tips on proper care.

Which cheeses are in the soft cheese category?

These are the most common soft cheeses: Brie, Camembert, mozzarella, cottage, ricotta, cream, neufchatel, feta, goat, manouri (a combination sheep and goat's milk cheese), and Mexican-style cheeses such as "queso blanco fresco" and queso fresco."

What are the two procedures that make cheese safe to eat?

All cheeses can be pasteurized.  If they are not pasteurized, they will be safe if they are sufficiently aged.  Since the 1940s, the requirement in the U.S. has been that cheese made with raw (unpasteurized) milk must be aged  at least 60 days in order to be sure that the product does not contain pathogens such as Listeria (a harmful bacteria). According to Dr. Clair Hicks, a food scientist and specialist in cheese, "After an adequate aging period, the normal flora of bacteria in the cheese overwhelm the listeria, and the listeria numbers decline to the point where they can no longer be detected."

Here are the problems with soft cheeses: Soft cheeses contain more moisture than harder cheeses. Therefore, they reach their optimal flavor very quickly, usually much sooner than 60 days. As a result, if they are manufactured from raw milk, pathogens will still be present when they are consumed. Dr. Hicks's points out the following, derived from his research: "At least 90 days of ripening are necessary to eliminate Listeria that are present in raw milk cheeses.  Most soft cheeses (for example Brie) would be past their prime point for consumption by 90 days.  Therefore, my recommendation is that no fresh or high-moisture cheese ever be made from raw milk.  Only the low moisture cheeses, such as cheddar, can be made this way.  Lower moisture cheeses can be aged for more than 6 months; then, the fine flavors developed from using raw milk can be a great attribute to the quality of the hard cheese."

Although the Food Safety Modernization Act may extend the rule to 90 days, presently the U.S. is still using the 60-day rule for raw milk cheeses. There are still outbreaks occurring for this class of cheese. Currently, there is a recall in Alaska for a raw milk cheese containing the bacterium campylobacter.  Kenny Cheese in Kentucky had two recalls in 2012 for Listeria in its raw milk cheeses that were held 60 days.

There have also been problems with both domestic and imported products that have not been aged for 60 days.  However, in recent years, the FDA has been doing a better job of identifying cheeses that are not sufficiently aged and keeping them from entering the country. 

Why aren't all soft cheeses pasteurized for safety?

Some people (especially artisan cheese makers and their customers) claim that cheeses made with raw milk have a distinctive, especially delicious taste.

Is the risk of contracting listeriosis high, and is the illness dangerous?

Some healthy people who consume the bacterium Listeria monocytogenes may not develop any symptoms at all, but others may have flu-like symptoms: fever, headache, nausea, stomach pain, and diarrhea.  The condition, which can be contracted from other foods in addition to cheese, affects about 2,500 American a year.  However, pregnant women are 20 times more likely to be affected, and listeria can cause the death of the fetus or a stillbirth. 

How can consumers tell if the soft cheese they are thinking of purchasing is safe?

The product should either be pasteurized or labeled "aged for a minimum of 60 days" or similar wording. That is what U.S. law requires. (However, keep in mind that 60 days may not be long enough for soft cheeses to be safe.)  The word "pasteurized" may be prominently located on the front of the package.  But, if not, check the list of ingredients (in smaller print, perhaps on the back or side of the package).  That will list "pasteurized milk" as an ingredient if that's what it's made with. 

Here is Dr. Hicks' reassuring comment: "So as long as you are buying cheese from a major chain supplied by a major cheese manufacturer, you're pretty safe because these companies check their sanitation and are not willing to do things that violate the law (as a small manufacturer might be)."  According to Dr. Hicks, in the U.S., if a cheese is made with raw milk, that is usually stated on the package.

If you've purchased a hard cheese and then cannot find any statement on the packaging about pasteurization, Hicks suggests aging it in your fridge for 90 days.

What about imported soft cheeses? Are these safe?

Here's Dr. Hicks' answer: "I would assume that all of the Brie cheeses sold in the US are made with pasteurized milk; otherwise, the label would have to say 'Aged for at least 60 days.' All imported fresh cheese would also be made from pasteurized milk also, or they would be illegal.  I know all of the French Brie cheeses are pasteurized." In other words, read labels or, if you're buying cheese at a deli counter, ask the salesperson what the label on the block of cheese says.

Can I safely eat cheese when I'm traveling abroad?

Be careful about soft cheeses.  Dr. Hicks says this:  "I would never consume an unpasteurized soft cheese in a foreign market. There is just too high a probability that it will be contaminated with a pathogen like Listeria."

Is it safe to leave soft cheese out to warm up to room temperature?

As you've probably discovered, some soft cheeses--such as Brie and Camembert-- display more of their natural flavor and have a more appealing texture when they're left out for 30-60 minutes before serving.  However, unripened cheeses--such as mozzarella and cream cheese--should be served cold and be refrigerated as soon as possible after serving.  

Clemson Cooperative Extension (a Clemson University website) urges consumers to follow this rule: "Throw out soft cheeses that have been at room temperature for more than four hours."

How long can I keep soft cheese?

Guidelines from Clemson University give this tip: the harder the cheese, the longer its shelf life.   "Hard cheeses will generally keep for several months, whereas softer cheeses will keep from one to three weeks after opening." Remember, a future "use-by" date is irrelevant once the product is opened.

Pasteurized soft cheese has a longer shelf life than unpasteurized.  Once soft cheese has passed its "use-by" date, quality begins to diminish.  If you don't expect to use all of the cheese by then, you can freeze some of it.  Dr. Hicks says most soft cheeses will be okay after freezing if they are tightly wrapped (skintight) before going into the freezer and defrosted in the fridge for 24-48 hours before consuming.  The cheese should taste fine, but the texture may have deteriorated a bit due to freezing and defrosting.

Is mold in or on cheese dangerous, or can I just trim it off and eat the rest?

Mold can be dangerous to consume.  Food scientist Dr. Susan Brewer says, "With few exceptions, moldy food should be discarded."  Regarding cheese specifically, she offers the following guidelines:

• ŸIf mold is used to make the cheese (as is the case with Roquefort, Stilton, Blue, and some other cheeses), you can trim the cheese at least one inch from where you see mold, and save the rest of the cheese.
• ŸMost soft cheeses should be discarded if any mold is visible.  This includes cottage cheese, cream cheese, and Neufchatel.
• ŸCrumbled, shredded, and sliced cheeses should also be discarded if any mold appears. 

For more information and sources on cheese and listeria, go to the following Shelf Life Advice articles:

Are Soft Cheeses Dangerous? 

How do hard cheese and soft cheese differ? 

How dangerous is listeria? 

Is cheese addictive?  Only if you eat it 

To reach this site's product section on cheese (which contains numerous Q/As about different types of cheese), click on Cheese.

Source(s):

Clair L. Hicks, Ph.D., University of Kentucky, Dept. of Animal and Food Sciences

Susan Brewer, Ph.D., University of Illinois, Dept. of Food Science and Human Nutrition

Clemson University, Clemson Cooperative Extension “Handling of Cheese for Safety and Quality”

http://www.clemson.edu/nextension/hgic/food/food_safety/handling/hgic3506.html