Here are some important tips to keep your bento safe:
Before Packing
- Wash your hands and make sure your bento box is clean.
While Packing
- Use clean utensils (chopsticks etc) or plastic gloves when you touch food. Your hands have germs and it’s better to avoid touching with hands. If you touch one food to the other with the same utensil, wipe off the utensil in between, or simply use another utensil. If you decide to wash it, then make sure your utensil is completely dry before picking up another food.
- Highly recommend to re-heat pre-cooked/leftover food before packing. If you do so, I also recommend to heat up with a pan or toaster oven instead of microwave so that food, especially meat, is heated THOROUGHLY and not partially.
- Before you pack cold/cool food in your bento box, hot/warm rice must be cooled down. It’s dangerous when hot/warm rice heat up other food halfway because bad bacteria would start growing.
- Remove all liquid from the food which could spoil faster.
After Packing
- To avoid risk of any bad bacteria starting to grow (bacteria love a warm moist environment), you must cool down the food first before closing the bento, especially if the lunch box will stay at room temperature until lunch time.
- Use ice packs to keep food fresh and safe till lunch time.
Why do we reheat food?
Japanese Bento is meant to eat at room temperature. Please remember that the longer food has been lying around, it gets less fresh, even you put ice pack or keep it in the refrigerator.
Therefore, I highly recommend to reheat cooked food before packing lunch. Reheating cooked food kills bacteria. It’s better to take extra safety precaution especially if you live in humid or hot weather.
All you need to do is to reheat the food, let it cool down completely before closing the bento box (bacteria grows in warm moist environment), and then keep the bento cool with ice pack whole time with till lunch time.
However, if you can keep your bento box cool all the time and can reheat prior to lunch, it is okay to pack lunch previous night instead of reheating and packing in the morning before you leave the house.
Read more about food poisoning and food spoilage here, here, or here.
Hello! I’m in Indonesia and I love your website!
I always prepare lunch boxes for my kids too. But the main problem is the same: I cook in the morning, and put all the warm/hot food ( fresh cooked rice, fried nugget, boiled sausage, etc — everything hot directly to the lunch boxes); then the kids zoom out to school.
To avoid unwanted effect of plastic boxes, I use good quality stainless lunch boxes. Is it safe to put hot food at 7 a.m., then the kids will eat them at 9.30 or 10 a.m.?
Older kids even have to stay longer for school and they got “resting time” (can eat and rest) at 10 a.m. and 1 p.m… is it possible to make bento in the morning and be eaten at 1 p.m.?
Hi Mariani! Thank you so much for following my blog! 🙂
First of all, since you live in Indonesia, pretty warm/hot/humid place, I will take the safety extra cautious. In Japan, we have to be VERY careful to make bento because it goes bad fast due to the hot and humid weather.
Unless you use thermal lunchbox, I don’t recommend you to pack HOT food and close the bento box to eat later. Condensation from hot food will create warm humid place inside the bento box and bactaria thrive in such environment. If your children love hot food, can you buy thermal bento box so that it stays hot and don’t mix with other cold/room temperature foods?
You make bento at 7am and it’s okay to eat around 1pm too (probably not later than that). If you don’t use thermal lunch box, you need to cool down the foods first before you close the lunch box. You can put ice packs under and on top of bento to cool down faster. Then pack ice packs inside the lunch bag too, to keep it cool. Especially when it’s hot and humid day, it’s very important. 🙂
Hope that helps.
Great tips. I work at a flower shop so I’m able to keep my food in the cooler til lunch time. Lucky me 🙂
Thank you Faith! 🙂
What if you wanted to eat 5 meals away from home. Would you reheat all of them, cool them down, and put an overpack with them? I like the idea of eating room temp food safely but I guess I’m confused as to why it’s needed to reheat the food if it’s been frozen the whole time. Wouldn’t that just keep it in the “danger zone” longer?
Hi Grant! If it’s been frozen, and you can keep it frozen until you heat it at your lunch place, then that’s no problem.
This “reheating” is for
– packing leftover food
– keeping lunch box at room temperature/cool place till lunch time (not in fridge)
– have no access to reheat before meal
– people live in the area with high temperature and humidity.
Basically reheating kills bacterias and by re-heating in the morning, you may stop the food from going bad.
If you live in a cold place, you don’t have to worry as much as someone who lives in hot and humid place. It is important for me to talk about it for everyone, as I include “leftover” food from previous night into lunch box.
hello ^^ i really like your blog but i have a problem
I’m 15 and i’m thinking of preparing a bento box for myself because my mom usually doesn’t because since we’re from Pakistan and only i’m interested in japanese stuff my family doesn’t even know what a bento is,but the problem is that whenever my mom used to make a lunch box for me when i was young the food would always be stuffed at the side of the box(partly because i placed it vertically in my bag) but i really need a solution for this….thank you
p.s. i’d also love some easy to cook suggestions for the bento
Hi Abdul! Thank you so much for your kind comment! The only way to keep the food in place is to pack tightly. Lunch box with compartments or silicon cups help a bit but the key is to pack food tight that it won’t shift. I always put leftover main dish in bento. And fill in the gap with veggies etc. Hope this helps!
^^ thank you very much i’ll try that
oh i forgot to ask sorry ^^……..in the bento box is there a good replacement for meat,chicken cutlets etc?
Hi Abdul! You really can put anything you like. There’s no rule for what needs to be in the bento box. Well, no raw food, but that’s about it. 🙂
I am very much impressed by the wide variety of recipes and wealth of useful cooking related information that is contained on your website.
Hi Edwin! Thank you so much for your kind words! 🙂
any tips for how i can pack my bento in my backpack without squishing it owo and also is it ok to keep a boiled egg out for more than 5 or 4 hrs ?
Hi SN06! I usually pack in bento box, then put it in an insulated lunch bag with ice packs in it. For boiled egg, 4-5 hours should be okay as long as bento box is in an insulated bag with ice packs (but when I was small, we didn’t have an insulated lunch bag and a boiled egg was in the bento too….). 😀
Do you know a good thermal lunchbox I can get? I have been looking around for one, but I can’t find one that people say actually keeps the food warm.
Hi April! My kids use Thermos Food Jar. I pour boiling water into the jar twice (hot water become warm immediately after pouring for the first time, so I do it again to make sure inside is hot) before adding lunch inside. My kids say the food is “warm” (not hot) when they eat. They said it’s okay. Hope this helps!
Here’s the link: http://www.thermos.com/product_catalog.aspx?CatCode=FOOD (You can buy on Amazon).
Hi,im only 12 and i am thinking of preparing bento for myself and i am not really sure about the basics,what items i need etc. so i am hoping that you can tell me about those and where can i buy my supplies in singapore
Hi Penny! So sorry – I somehow didn’t see your comment till now. I apologize for my late reponse.
Here’s the main page for Bento How To…
https://www.justonecookbook.com/bento-how-to/
And I hope this tutorial is helpful for you.
https://www.justonecookbook.com/recipes/how-to-make-bento/
And in terms of shops… http://en.bentoandco.com/ is a very popular site. 🙂
Hi Nami! I’m fifteen years old and for my next birthday, I wanted have a Japanese themed birthday party including bento boxes.
I have two questions:
1. Do you know where I can get bento boxes in bulk?
2. What are the best foods that everyone likes in their bento boxes?
Thank you, Jada J
Hi Jada! Happy Early Birthday! 🙂 Here are my answers:
1) I’m not sure if you can buy in bulk, but ask an online shop like http://en.bentoandco.com/?
2) What’s your popular Japanese (bento) food in your country, and which dishes are familiar to them? Maybe onigiri (rice ball) and karaage, etc? Popular foods in Japan can be different in another country.. 🙂
hihi Nami. I’ll be starting my intern and my allowance from it wouldn’t be enough to cover my lunch so i was thinking of packing food to work… but problem is i’m not a morning person and i was just wondering if it’s possible to pack my bento before bed and then take it out of the fridge after that without reheating in the morning since it’ll probably be at room temperature at lunch? do i have to ensure that the lid is closed only after it’s cooled down? can’t i just close it immediately and dump it into the fridge? sorry, i’m quite new to cooking and these are all like rocket science to me hahaha. thanks for the wonderful recipes. 🙂
Hi Sharmine! Do you live in hot and humid area? If not, I won’t worry too much. However, if you do, try to keep your lunch cold from previous night you make bento until you are ready to eat. It goes bad when the food is at room temperature. Also, please put the lid on after cooling down. The condensation from the lid (if you put the lid on when food is still hot) should be avoided. It is great if you can re-heat the lunch (with microwave?) if you can. Hope this helps! Good luck with your internship! 🙂
Hi! Thank you for sharing your advice. I’m going to be a new bento-user (waiting to receive my bento box). I was wondering, what if you don’t have the option to heat your food at work? We don’t have a microwave at work. But we do have a fridge, where I can keep the box cool. In this situation, should I only eat ‘cold’ food, like fruits, veggies and (cold) rice?
Hi Dubu! Traditionally, we eat bento at room temperature. Kids at school and people at work… we are all accustomed to eat room temperature bento. We only put food that tastes good at room temperature too. So that’s one reason why we even put bento ingredients in non-thermo bento box. These days people might microwave as bento box became “microwavable”. We usually keep the bento at room temperature (unless it’s hot weather), or cool with ice pack or in the refrigerator (if available), and eat at room temperature. If you prefer warm food, you might want to consider thermos jar that can keep the food relatively warm till lunch time (not hot). Hope this helps… If you want to use your new bento box, choose ingredients that you enjoy at room temp or cool. 🙂
I’m a 16 year old high school student. I am not Japanese, though I really love everything about the country and culture. I want to prepare a bento box, but I’m at a loss as to how to do it safely without having to worry about getting sick. I know you covered a lot in this article, but I’m still confused. Can you make it any simpler for me?
Hi Billy! If your school doesn’t have an microwave to heat up your lunch, you need to make sure your lunch is kept cold till your lunch break. You should pack food that you can still enjoy at room temperature. If you are going to pack previous night’s leftover, you can pack at night and keep in the fridge overnight, then pack in insulated lunch bag (with ice pack) to bring to school. In Japan, we try to make sure food safety by re-heating the leftover in the morning (to kill any germs). Whenever you put warm food in the lunch box and close the lid, it creates condensation. That water will cause the food to go bad. Therefore, you need to cool down the food before you close the lid. That’s pretty much basic rule. If you still need help on this topic, tell me your senario in details so I can help you better (you can email me too). 🙂
HI Nami. Is it okay if I pack my food overnight and don’t re-heat it the next day when I have it for lunch? Are the foods that I shouldn’t eat cold?
Hi Sonya! In Japan, we always recommend to re-heat the food before packing in the morning. However, if you can maintain your bento cold throughout the time (no temperature difference), it should be okay. We eat bento at room temperature (that’s a part of bento culture). If your school or work doesn’t have a microwave, then you should pack some food that’s good at cold or room temperature. I grew up with cold/room temp bento so it doesn’t bother me, but if you’re used to, you might want to choose the right menu. 🙂
Hello,
I’m a new bento user and I have a few questions, let’s say I cook everything in the morning before i leave for my classes in my university, and i pack it at around 8 am to eat it at around 1:30 maybe 2:00. I should use ice packs right? especially in this weather right now, and do i put the ice packs inside the bento box itself or on the bag I’m carrying the box in? Also I like to eat a lot of meat, any ideas on what would be great for a bento box and how do I pack any kind of meat inside the box? and how do you keep the rice fresh inside the bento? Finally do you recommend any ice packs?
I’m sorry for the questions, I just need to get everything right before packing my lunch.
Hi Noah! Unless it’s in winter or cold weather, I highly recommend to pack your bento in insulated bag that also contains ice packs.
The ice packs goes outside of bento box, but when you put your bento box in your insulated lunch bag, you should put ice pack very close to the bento box.
For meat, I recommend some meat that’s less fat, especially you pack with ice pack… all the fat will solidify. I avoid pork belly and high fat meat. Chicken and sliced beef/pork will work. And to taste good at room temperature, I recommend to season it a bit more than usual.
For rice, Japanese rice usually stays moist and won’t dry as long as you seal the bento correctly.
I don’t have any particular ice packs that I recommend, but I use the ones that came with the lunch box (and the ice packs go to the net pocket area).
Hope this helps! Feel free to ask me anytime. 🙂
Hi! Question about your above post regarding bento food safety. So if i pack my bento the night before to eat the next day for lunch do I have to re heat the bento? How do you re heat if your bento box is stainless steel or plastic? Thanks for any tips!
Hi Ocsliew! For food safety (because I don’t know how everyone keeps their bento till lunch time), I always suggest how Japanese make lunch traditionally. We do not pack bento items inside the bento box till the morning. We always re-heat leftover food in a pan/toaster oven/microwave first. Then let it cool down, and then pack. This will prevent bacteria growth. In Japan, most cases, we do not store bento in the refrigerator after you leave the house, so it’s important that food stay safe till lunch time. If you can bring to work or school and keep it in the fridge, you can pack at night and then keep it cool all the way till lunch time. Then you can pack previous night. Hope this makes sense. 🙂
Hi Nami, sorry for asking so many questions but I’m still a bit confused. I was wondering if I do reheat my food in the morning, then keep it in an ice pack and bring it to work (without keeping it in a refrigerator or microwaving it at lunchtime) then by lunchtime do I eat the food cold? And if I leave it to warm, won’t the bacteria grow? Also if I get the lunchbox ready at around 9.30-10 do you think it’s possible for it to be safe to eat at say 6-7pm?
Thank you!
Hi Cheryl! First of all, please remember. Bento is meant to eat at room temperature or cool (due to ice pack) in Japan. So yes, we eat food cold. We choose ingredients and food that taste good without heating up. But at the same time, Japanese are used to eating bento and although we love warm/hot food, we expect bento dishes to be eaten that way…
If I understand correctly… you pack lunch in the morning (reheat + pack). Bring it to work in lunch bag with ice pack. Eat it without heating up.
What you need to do is to make sure after reheating the leftover food in the morning, make sure to cool it BEFORE packing in the lunch box. This “cooling” is to make sure there will be no condensation inside the lunch box when you close the lid. That is bacteria friendly environment.
IF you live in non-humid place, you don’t have to worry as much, but I can’t be responsible for food safety so I recommend everyone to “re-heat” just like how Japanese people make lunches. Some meals can be packed previous night and keep it in the fridge till morning. Then pack with ice pack in the lunch bag to bring it to work. But in general, I recommend everyone about reheating because that’s for sure kill bacteria that might have been growing. I don’t know what everyone is packing, so this is a general guideline (and standard procedure in Japan).
And packing lunch at 9 am and eating at 6pm sounds a little too long if it’s not properly stored in a cool place. I can’t tell how long ice pack has been cold so I won’t be able to say that’s safe to eat.
Hope this makes sense! 🙂
Why must the bento be interesting?
Hi Yaya! What do you mean?
Hi Nami,
I like your blog and had try some of your recipes. thanks ya. Next I may want to try your bento recipes for my son in school, but before that wanted to ask if I prepared my bento in the morning say like 7am then only eat at 3pm, will it be too long? At here temperature is around 33 Celsius and it is humid. Thanks for your advise in advance.
Hi Michelle! Thank you for reading my blog! 33C with humidity, I’ll make sure to pack ice packs and it keeps the food safe. Ask your son if his lunch was “cool” when he opens. You can definitely bring lunch box, but you need to make sure it’s stored safely. 🙂
Hi Nami,
Thanks a lot for your advise and reply…
I would like to know if it ok to take a bento box to work frozen and then by lunch time it should be thawed to eat?
Hi Tasha! Does your work have an microwave or do you plan to eat just out of the box after begin thawed. Some foods works great like that. In Japanese bento menu, Tamagoyaki for example can be frozen and put it directly into lunch box and thaw to enjoy. However, some foods are not good without reheating. So as long as you pack foods that are good at frozen-thaw-eat process, it should be okay.
Hi! You must be tired of so many questions, but I have to ask: which are those foods that can be thawed to eat? I suffered a gastritis recently due to an infection of h. Pilory. I’m avoiding eating food from the street,and the only way I could carry my bento to the university would be freezing the food in the night and carrying out in the morning (I’ve been cooking my lunch in the morning, but it’s too much time consuming,and I’m afraid it won’t cool down completely before I close the lid)
Could you recommend some options for me? I mainly eat chicken breast, fish, eggs, rice (with vegs or plain), pasta and cooked vegs, and I’m really afraid of getting another bacterial infection 🙁
Ups! I forgot to add:
-I live in a tropical country
-I can’t get a proper bento box, but I have a lot of BPA-free plastic containers with air tight lids
-I don’t care about eating cool or room temperature food,as long as it’s safe
-I don’t have access to a microwave to reheat the food before lunch time
Thank in advance!
Hi Angie! No worries. I try my best to respond to questions when I have time. Since you live in a tropical country and the temp is relatively high (germs like warmer environment), I would really recommend re-heating your meal. BUT if you can keep your lunch cold till lunch time, you can pack at night, keep in the fridge, then bring to school. I can’t recommend homemade frozen food directly put inside bento and bring. In Japan we have some frozen food that you can pack in bento,etc. But those are flash frozen in a special freezer not home freezer (too slow). So bacteria might have grown. I mean you always want to take safe side, especially with your recent health condition. The best choice would be prepare at night, keep your lunch cold all times till your lunch time with ice pack etc. 🙂
Thanx! I’ll search for some recipes that I can eat cold.
Would a bottle of freezed water work as an ice pack?
Hi Angie! In general, gel-pack lasts longer time than own ice (and it gets wet around the bottle).
http://amzn.to/1rmo5TM
Before you pack cold/cool food in your bento box, hot/warm rice must be cooled down. It’s dangerous when hot/warm rice heat up other food halfway because bad bacteria would start growing.
Just wondering, to what temperature should the rice be cooled down to? Slight condensation in bento box pose any health risks? Thanks.
Hi Michelle! The bacteria loves the temperature 86-39F (30-40C) so you will need to cool down to below 50F (10C) to be safe with ice pack etc.
Hi Nami! Thank you so much for posting all this info about making bento! I’ve been wanting to try making bentos, but the problem is the waiting time to let all the reheated food to cool down. I’m not much of a morning person, and I’d rather not have to wake up 2 or more hours earlier before classes just to make sure the food has cooled down enough so that I can pack it. So how long does it take usually for the food to cool down, and do you have any tips on making them cool down faster? Also, should I let the food cool down on a separate plate first before putting them inside a bento box, or should I just pack them all in the bento box while still warm, and just let it cool down without the lid on? Thank you in advance!
Hi April! I totally understand and I feel the same way. I use ice packs – place the bento box on top of ice packs and it cools faster. And It’s much faster if you cool down on a plate, then pack in silicone cup, then put inside bento box (while you put rice in the bento box and let it cool first). Bento box has “sides” that will retain heat, so if you are short on time, use plate to cool down. You can also prepare at night time too, as long as you can keep it safe till lunch time. 🙂
Hi Nami,
Like to ask a question about use of cheese in bento. Can I use it straight out of the package onto bread? Or should I bake it after assembly to prevent it getting spoiled? I usually use Kraft slice cheese.
Many thanks,
Dawn
Hi Dawn! I recommend keeping your bento cool until you eat at lunch time. As you know, cheese “should be” kept in refrigerator. I think a few hours of “cool” place should be safe to consume, but I don’t recommend room temperature for a long time. Hope this helps! 🙂
I make bentos for lunch at school (because I don’t trust my family to make my lunch anymore) and our classroom is airconditioned most of the time so we get to keep our lunch there. I pack my bento in plastic inside a insulated lunch bag with an ice pack but I would like to keep my food warm for a change. Can I pack food hot in my bento?
Hi Avery! I pack hot food in a thermos jar.
http://amzn.to/2mPPr3m
I pour boiling water in the empty jar twice to make sure inside is super hot when I place hot food in it. My kids say it’s “warm” enough at lunch time. You won’t be able to keep the food hot in the regular bento. 🙂
Hi Nami, I just read this and found it very helpful. Just wondering, do you also put ice pack in rice bento? Do you usually eat them cold? My child doesn’t like cold food and it’s quite a hassle for her to take the food out beforehand to let it adjust to room temp – also no space either. I still haven’t found the solution to this, hopefully you can help me 🙂 Thanks before
Hi Maya! I just found your comment when I came to respond to the comment below you. Somehow I didn’t see it until now. I am so sorry for my late response.
If it’s in a cooler place, you don’t have to put ice packs (when I was growing up, we didn’t have ice packs back then and we kept bento box wrapped in cloth etc). I usually pack a small ice pack underneath the fruit box, so fruits stay cool, but bento box has no direct connection to ice pack. Hope this helps!
How can I reheat stuff without microwave? Can I reheat frozen rice with oven or pan?
I honestly don’t know what’s the best way… You can “steam” the rice but it defeats the purpose of convenience. It’s probably faster to cook fresh rice…. But if you can keep the steamer on, you could steam it. Oven or pan don’t work if you want to reheat frozen rice. 🙁 Sorry…
After allowing your meal to cool down, can’t you just store your bento in the fridge over night so it stays cool?
Hi Kyle! If you can keep the lunch from refrigerated temperature to your lunch box with ice (similar temperature) to the fridge at work, then yes, you can definitely do that.
Food tend to go bad when the temperature changes, and bacteria loves lukewarm environment. In Japan, we eat bento at room temperature, so we always heat/reheat the food in the morning to kill any bacteria that might have grown overnight, and bring to school/work. 🙂
Hi, if I were to pack the lunch box into a thermal bag or having a thermal lunchbox and leave it in for 3-4 hrs. Will it help? Thanks!!
Hi Jadie! To keep it warm? Yes, I do that too, but my children say it’s “warm” not hot. To keep it cold, you can also use it too.
Hello! I’m a little confused on what food should be reheated and not reheated. Should spinach namul be reheated before putting in the bento, or can it be put straight from the fridge? What about stir fried onion? For meats and proteins, it is obvious that they should be reheated, but I am unsure about cooked vegetables. Thank you!
Hi Joon! Good question. If the food is cooked (stir fry, steamed, grill, etc), I’d reheat before adding to a lunch box. If it’s chilled salad/vegetables, I would not reheat, like in this Namul case. We don’t eat that dish hot. If the onions were stir-fried before, I’d definitely heat up. If the vegetable is blanched and seasoned (namul, spinach salad, etc), you do not need to reheat as you didn’t cook the dish. You coat the blanched vegetable with sauce. Hope this makes sense. 🙂
Thank you for this information! Just to understand, if I pack my bento the night previously, and it will remain in the fridge at work, the reheating process can be skipped? The only downside is that it would lose freshness?
Hi Meghan! That’s okay as long as the food doesn’t go through different temperature. 🙂
Amazing, thank you! Please keep posting, I’ve tried a couple of recipes with great success!
I’m so glad to hear that. Thank you for your kind feedback, Meghan! xo