Packing a lunch: when to heat and when to eat?

September 29, 2016 12:13 AM

This might win me the award for most embarrassing question of the day, but I don't like messing around with bacteria in my food, so I should probably figure this out.

Sometimes, when there is no microwave available to me at work, I've heated up food (from the fridge) in the morning, packed it in my lunch bag, and then headed off to work, eating it 4-5 hours later, at lunchtime. Is this safe to do, or should I always be heating my food up in the microwave right before I eat it? I generally try to bring dry stuff like stir fry or pasta.

posted by madonna of the unloved to Food & Drink (13 answers total)

Is it in a thermos? Do you measure the temp ever? I don't think you are helping things to re-heat and then to slowly cool.
posted by amanda at 12:16 AM on September 29, 2016

Food can safely be in the "danger zone" (between 6 and 60 degrees celsius) for up to 4 - 6 hours but you have to remember that this is cumulative. Taking into account the time that your food would have been in the danger zone while cooling down after being cooked and the 4 - 5 hours that you're leaving it sitting out and warm, I think you are pushing it a little. I'd recommend storing the food in the fridge and heating it up just before eating, or storing food in the fridge and eating it cold if there is no microwave available.
posted by kinddieserzeit at 1:00 AM on September 29, 2016

First of all, I was once a working chef (cognizant and mindful of strict health regulations both enforced and best practice) + a "super taster." Please assume that slightly "off" food is unacceptable to me.

Also, please note that I have a young child that appears to have inherited my tastebuds - extreme flavors are fine! Spicy! Bitter! Sweet! These are OK! ... Leftovers are adamantly rejected. Fake, processed, or fast foods are disgusting. His exacting palate makes my life a hell my culinary degree did not prepare me for...

I once knew a chef/alcoholic that worked the boats in Alaska and was just totally knowledgeable, he lived with a family at the time I knew him that left food in the pot on the stove overnight all of the time. It was delicious and leaving food out was cultural.

Granted, his body was mostly alcohol so that killed a lot of internal beasties he ingested, but his experience and the cultural practices of his host family really changed the way I view food safety...

I'm still a germ-a-phobe. But I now can distinguish between flavor and safety. Also, some flavors are better over time. Plus, slightly fermented food (even fermented by accident) is super healthy for your gut flora...

What was the question?

IN GENERAL YOU WANT TO LEAVE FOOD COLD UNTIL YOU THOROUGHLY REHEAT IT, KILLING MOST MICROBES.

As per your example, you've been doing it wrong and inviting trouble. Or a Mtzvah. Depending on the item and condition of your gut flora.

In general, keep it on the low end of refrigerator cold (below 40 degrees F, but above freezing at 32 degrees F) before reheating. That's The Rule.
posted by jbenben at 1:04 AM on September 29, 2016 [4 favorites]

Response by poster: This is what I use:

I also bought ice packs for it, so I can use those to keep my lunch cold until it's time to heat it up.

Thanks!
posted by madonna of the unloved at 1:18 AM on September 29, 2016

I have solved this by packing South Asian/East Asian/Middle-Eastern style cold/cool lunches based on the previous night's dinner and keeping them piping, er, cool in the fridge until it's time to eat, maybe taking them out for an hour to warm up to room temperature.

I live in Hong Kong so I am surrounded by Asian ingredients but in almost every large city in the US, if not online, you should be able to get you everything you need.

I sort of cycle a few different things on days when I can't heat something up:

- baked-in-foil salmon fillets on top of brown/red/wild rice, packed so the juices from the fish infuse through the grains while in the fridge

- any kind of chopped-up crispy veggies, falafel, and hummus/tzatziki/other dipping sauces

- cool/cold salads with a protein like sliced chicken breast and a crispy carb, with separate dressing that one adds at the moment you want to eat to prevent sogginess - in the US, I've seen things like this called "Chinese chicken salad"

- vague renderings of bun cha (grilled pork sliced up and marinated in lemongrass/chilli with very thin cellophane noodles and herbs)

- Vietnamese style sandwiches - package up pre-cut banh mi ingredients and assemble your sandwich on a crusty roll

- tiffin-like servings of lentils, paneer, rice and maybe a small portion of a curry that wouldn't be bad at room temperature; South Indian food has a lot of options in this department
posted by mdonley at 1:26 AM on September 29, 2016 [3 favorites]

I don't understand why you heat it up in the morning. It'll be down to room temperature again by the time you eat it, so why not let it slowly reach room temperature on its own? (Or put it in a Thermos to keep it actually hot the whole time?)

I can only give anecdata to answer your question... I leave unchilled, unheated food in my bag until lunchtime and have never had a problem. This is food that was often sitting out for a few hours after being cooked already, but I don't eat meat.
posted by metasarah at 3:56 AM on September 29, 2016 [5 favorites]

I have been doing the exact same thing for 10+ years and I haven't died (as is evidenced by this post). I'm eating it now.
posted by ihaveyourfoot at 4:44 AM on September 29, 2016

I also am confused about the heating it up in the morning step.

I bring my lunch to work in a grocery bag, shove it in my desk drawer, heat it up in the microwave at lunch, and eat it. I have been doing this for my entire working life with no problems.
posted by something something at 5:54 AM on September 29, 2016

OP says they do this when there is no microwave available.

I say it is OK if the lunch container is insulated enough to keep it hot enough to be out of danger. You could try adding hot packs to the existing insulated bag. Or using something like a Mr. Bento kit: hot food goes on the bottom in extra-insulated containers, then side items that can stay cooler (like raw veggies, fruits, crackers, etc.) go in containers on top, and all of the containers go into a big Thermos.
posted by snowmentality at 6:50 AM on September 29, 2016 [1 favorite]

Guys the OP is using an insulated container. I assume the food is staying hot.
posted by showbiz_liz at 7:07 AM on September 29, 2016

Sorry, missed the insulated container comment. You'll be fine, especially if you get it really hot in the morning.
posted by derbs at 7:10 AM on September 29, 2016

This sounds like what every child who carries a lunch does. Sandwiches stay cold, maybe, but we heat pasta, chickent nuggets, and lots of other things in the morning, packing them in an insulated container. Offspring and all her classmates seem to be surviving...
posted by acm at 11:40 AM on September 29, 2016

Yeah, if you're already using something like a Mr. Bento, hot food will stay hot and cold food will stay cold for 6 hours (and you can have both hot and cold in the same lunch). If you're not using a Mr. Bento, get one.
posted by Bretley at 4:05 AM on October 1, 2016