Anyone who has ever frozen food in a Ziploc bag and then forgotten to get it out in advance of a meal has wondered whether you can and should microwave Ziploc bags. We are becoming increasingly aware of how dangerous plastics can be and the chemicals they might leach into food, and this might leave you doubting whether it’s safe to microwave these bags.
You may also have observed that when microwaved for a long time, they melt and tear – and that can’t be a good thing. Overall, then, is it safe to microwave Ziploc bags?
Can you microwave Ziploc bags? Yes, you can microwave branded Ziploc bags for short periods of time. The company claims to adhere to all safety standards and says that its products are all safe to heat in the microwave. As long as you follow their guidelines and do not heat the bags for too long, you should be fine.
Are Ziploc Bags Safe To Heat?
Many of us worry about the health problems associated with heating plastics and the potential chemicals that could leach into the food. However, Ziploc bags are BPA free and should not leach any chemicals that we are currently aware of when heated according to the guidelines.
Ziploc bags are made of polyethylene plastic, and they are also free from dioxins and recyclable. The plastic should not soften until it reaches temperatures of around 195° F, so as long as you are not pouring boiling water over it or raising the temperature of the food inside above boiling, it should not be degrading or leaching.
In theory, Ziploc bags therefore remain inert and are safe to microwave up to a point. However, you should make sure you are following guidelines and not being careless, or you might end up ruining dinner!
Of course, the safety claims do not necessarily allay everyone’s concerns. Some people still feel that Ziploc bags are not safe to heat, and that you shouldn’t put them in the microwave, even for short intervals. Ziploc themselves offer some advice on how to use their product in terms of heating it, and what you should not do.
How Should You Heat Ziploc Bags?
If you need to microwave a Ziploc bag, you should pay attention to the melting point. Apart from the potential health risks, there is the obvious concern of the bag melting into the meal you have made. You don’t want to be picking bits of melted plastic out of your teeth or heating the bag to the point that it tears, so be very careful about this.
You should aim to put your microwave on for short intervals when you have a Ziploc bag in there. Thirty seconds is about the maximum burst you should use. You should also turn the temperature down so that it is on low or medium. Check on the bag and the food at every interval, and allow it to cool a bit before putting it back in the microwave.
Test the bag’s texture if you are worried that it is getting too hot. Before melting, it will become stretchy and soft, so make sure that it isn’t starting to do this. If you notice an unpleasant smell, you should discard the bag and the contents, rather than risking eating food where the bag has started to break down.
Ideally, you should tip the contents of the bag out into a microwave-safe dish (such as a glass or ceramic bowl) as soon as they have defrosted enough to do so. Wash and reuse or discard the Ziploc bag, and resume heating in the microwave as before, without plastic touching your food.
You should never cook in a Ziploc bag. They are not designed to withstand the temperatures of a hob or oven and will very quickly melt into your food. They will smell awful, and could add some really unpleasant things to your meal.
Do not put a Ziploc bag in a pan to defrost it, and do not submerge it in boiling (or close to boiling) water. This kind of treatment falls outside the manufacturer’s guidelines and could result in contamination of your food.
What are the Alternatives to Microwaving a Ziploc Bag?
If you have accidentally left your food in the freezer too long but you don’t want to microwave a Ziploc bag, what else can you do? Resting the bag in warm water is a good way to speed up the thawing process. You can also leave it on the counter and wait for it to defrost enough to transfer it to another container.
Warm water is a good trick for helping food to defrost more quickly. Simply fill a bowl with cool or warm water (not boiling, remember) and place the bag in it. The water will help to draw the cold out of the bag and speed up the thawing process.
You should then be able to tip the contents of the bag into a pan or bowl, and either heat them on the hob or put them in the microwave. This ensures that the plastic bag has minimal heat applied while it is in contact with your food. It’s a good option if you aren’t convinced about the manufacturer’s guidelines.
Alternatively, you can simply set the food on the counter to thaw (assuming this is acceptable in terms of the contents and they don’t need to be thawed in a fridge). A warm spot is ideal, but even in a cool spot, the bag should defrost enough to tip out the contents reasonably quickly.
If you find that it sticks in places, running a little cool water over it should be enough to loosen the bag away from the contents and allow you to transfer them without tearing the bag or heating it up.
It’s not surprising that many people feel concerned about heating Ziploc bags in the microwave. We are becoming increasingly aware of the dangers of plastic and the chemicals that they can leach into our food, and heating them is the surest way to increase that chance.
However, Ziploc manufactures its bags to high safety standards, which is enough to reassure many users. If you aren’t comfortable microwaving Ziploc bags, try another solution or purchase non-plastic containers that can be frozen and safely heated in the microwave.