Christine Bruhn, PhD is the Director of the Center for Consumer Research at the University of California, Davis where she earned her doctorate. Dr. Bruhn has a special interest and passion for safe food handling practices. Her major area of research is in consumer attitudes and perceptions of food quality, safety and wholesomeness. Dr. Bruhn travels widely and is a sought after speaker at both academic and government conferences on food safety and food handling and food processing technologies . She currently serves on several education and advisory panels including the Food and Drug Administration's Risk Communication Advisory Group. In addition, she is often contacted by members of the media when questions of food safety make the news, especially in her home state of California. Along with her interest in making sure everyone knows “How to determine when your food had gone bad,” she is an avid cook and enjoys sharing practical food safety tips with her family and friends. For more information on food safety and nutrition questions, please visit IFIC.org.
How to Tell if Your Leftovers Have Gone Bad
Christine Bruhn, Center for Consumer Research at UC Davis, gives advice on how to tell if your leftovers should be thrown out.
Christine Bruhn: I am Christine Bruhn, University of California, Davis, the Department of Food Science and Technology. We have been talking about how to tell if your food has gone bad and today, I am going to be talking about how you can tell if your leftovers have gone bad. I tell you, it is not by taste and it is not by appearance. If they look bad, for sure throw them out, but if they taste great, you don't know if there is a bacteria lurching in there ready to get you within a few minutes, within a few hours or within a few days. What you have to do is handle the food properly in the first place and that's your assurance and the properly, means controlling temperature, keeping it cold, getting it cold fast and when it is time for reheating, getting it hot fast and then looking at the time and making sure your leftovers haven't been around for too long. This is some leftover pasta with ham and oh, it looks so delicious, but it has been around for about two weeks and good as it might taste, it could make us sick afterwards. So unfortunately, this has got to go. It has waited too long. This chicken was from a take-home meal and the great parts, so the breasts are gone, there is still some good meat left and it has been refrigerated, the critical factor here is refrigerated really soon after you are finished eating. Within two hours is the guideline and if it is a really hot day, like it is summertime, then you need to refrigerate within one hour. Bacteria grow in that temperature range between 40 degrees and 140 degrees. So the longer they are within that time range, the more they can grow, they multiply really fast and so you have got to get the food cold really fast. So if this was put into the refrigerator within two hours you are finished eating and it hasn't been around too long, then you are okay. How do you remember how long it has been around? This spaghetti sauce was a delicious product and when we brought it home, we put the date on the bottom. You don't have to say March or April or May. You can just say, Monday, Tuesday, Wednesday and if it has come Monday again and this was put in on Monday, it has been around too long. You should eat your delicious leftovers within 3-5 days of when you had them the first time and then you need to put them in the container where they are going to get cold quickly. So these containers are pretty good because they are relatively shallow. 2-3 inches is what's recommended. This container is really thick, about four inches. It is going to take too long for the food that's in the center here to get cold. Now in this particular case, we just had a little bit of leftover so being so thin, this probably got cold quickly enough. But you want to use a thick container like this for something other than perishable products. Maybe put nuts in it or cereals or something like that, not foods that have to be chilled quickly. The spaghetti sauce was a large pot and this package is almost pretty high for going into the refrigerator. The good thing is it is not very wide, so we are going to hope that this got cooled fast enough, but if you have got a big container of soup, chilli sauce, spaghetti sauce, put it in something small, put it in this, but then put it in an ice-bath. A few cubes in your sink with some cold water to help get it chilly fast. Do not put those big containers directly into your refrigerator. Cool them down first if you have got a lot of things. Then once you have them in the refrigerator, be sure to stack your leftovers, put them throughout the refrigerator so that they are not stacked so that the air can circulate and they can get cold fast. Once more, we want to get them down to 40 degrees or below as soon as possible. The other side of the equation is when it is ready to heat up again. It is so easy just to put them in the refrigerator and punch in a minute or two minutes, but what you really need to do is make sure it is hot enough all the way through. Steaminess, yes, steamy is good, but ideally and for greatest assurance, you need to use a food thermometer. The correct temperature for heating up leftovers is 160 degrees, 160. so stick your thermometer inside, make sure it has reached 160 and if it hasn't, put it back in the microwave or back in the saucepan once more to heat it again. Next, we are going to be talking about how to keep fruits and vegetables safe. How do you know when they are spoiled?