roasting veggies on a parchment-lined baking sheet

You have probably noticed that I line my baking sheets with unbleached parchment paper instead of cooking directly on the surface or lining them with aluminum foil.  And if I want to roast a head of garlic, I always wrap it first in unbleached parchment paper and then aluminum foil.  Since I have been fielding a lot of questions about this practice recently from some newbies in my cooking classes, I thought I would shed some light on it here.

There is research that suggests that when aluminum is heated (which is what we do when we cook, naturally), some of it leaches into our food.  The amount of aluminum that leaches increases with higher heat and acidity (e.g. wine, tomatoes, citrus.)  Although I use rimmed untreated aluminum or nonstick baking sheets almost daily for roasting vegetables or baking cookies, I always line them with unbleached parchment paper to provide a buffer so that my food does not come into contact with either of those materials.  I also never allow food to come into contact with aluminum foil when cooking.  If you own anodized aluminum cookware, this has been treated and sealed so that the aluminum doesn’t react or leach when heated.  This is ok.  There is, however, untreated aluminum cookware in restaurant supply stores and hardware stores and you should definitely not use these.

to roast garlic, wrap in parchment then foil

I will readily admit that any link between aluminum consumption and Alzheimers is controversial.  But aluminum is a known neurotoxin which means in excessive quantities, it disrupts the natural processes of a healthy brain and can lead to problems.  Um, no thanks.  We already consume aluminum whether we like it or not if we eat out or consume processed foods, drink municipal water, use vaccines or antiperspirants.  Many (not all) over-the-counter medicines such as antiacids and buffered aspirin, also contain aluminum although .   Read the product labels to know for sure.  This post isn’t intended to cover all sources of aluminum, but rather focus on protecting ourselves from this heavy metal in the kitchen.  So my point is that if I can control my exposure to aluminum at home in an easy way, I am going to do that.

I also want to specify using unbleached, and not bleached parchment paper.  Bleached parchment paper when heated can/may/might leach dioxin, which you can read about here and why I advise you to avoid it.  There are several brands of unbleached parchment paper which are available at your local grocery store or on Amazon.  I like Beyond Gourmet and If You Care unbleached parchment paper.  I also love these unbleached parchment baking cups for lining your muffin tins.  If you like to wrap a food in aluminum foil to roast in the oven or grill, simply wrap it in unbleached parchment first and then aluminum foil so it doesn’t burn like that head of garlic above.

unbleached parchment muffin liners

Please be be warned that parchment paper is not the same thing as waxed paper which is not meant to be heated!  Another option is to use silicone mats on your baking sheets which are washable/reusable and do not leach any harmful chemicals when heated.  I sometimes use silicone mats for mild-tasting food (like cookies, not fish) or for an easy-to-clean food (like cookies, not balsamic-roasted cherry tomatoes.)

As always, feel free to shoot me your questions or add your knowledge to this subject!

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58 Comments

  1. HI
    Is genuine vegetable silicone coated parchment paper safe or does it has to say unbleached

    • I think all parchment is silicone coated, but I’m not sure. Is it white or light brown? I like to be cautious and not use bleached personally.

  2. What are your thoughts about unbleached parchment paper that has been treated with a non-stick coating such as Quilon (there may be others, too)? It seems to me that that should be avoided, as well. Is it possible to get unbleached parchment paper that does NOT have a non-stick coating? Many thanks!

    • I buy one with a silicone coating. As far as I know, silicone is inert and does not leach.

      • Bleached or unbleached, it doesn’t matter. Parchment paper is one of those things we should also avoid if we want to do better for our health, and that of the planet. I gave up aluminum foil years ago and have never missed it. And I cook a lot.

        I finally ditched parchment last year, not sure I could, but it ended up being very easy! Glass baking pans, oiled and floured or just oiled, work fabulously!

        Silicone might be considered “safe” but that’s just for now. 10, 20 years? We might all be advised to ditch it.

        Plus, parchment paper is different than a silicone baking pan or mat. Those are “solid” silicone, whereas parchment is only coated with silicone. How do we KNOW for sure that’s not coming off on our food? We don’t.

        Better to be safe (and healthy) than sorry and sick. Go for glass! 🙂

        • Thanks Lynn for (re)Confirming many points..
          I think we should all revert to how cooking was done 30-40 years ago.. use Just glass and steel… no to paper and plastic
          eco friendly and human friendly

        • Question for you…I would like to ditch aluminum foil also, but what do you use to cover the top of a lasagna during baking? Or a whole turkey to prevent it from drying out? I’ve always thought that aluminum foil was just a quick step for cleanup (so not a big priority for me), but there are certain dishes that need a heat barrier during cooking. I’ve never really had a need for parchment paper, but research brought me to this post. Thanks!

          • If the foil doesn’t touch the food, use it. Otherwise use parchment and then foil on top of that.

        • Lynn, that glass baking ware you’re using is made out of silicon…just like silicone bakeware.

          Also, aluminum is the most common metallic element in the earth’s crust. It’s in all the food we eat, all the vegetables and fruits we grow. No need to avoid it — it’s only implicated in things like Alzheimer’s because the body starts storing it improperly in the brain, not because it is, in itself, toxic.

  3. Hi,
    I cook about 2 weeks of chicken and turkey and store it in the freezer. I am switching immediately to unbleached parchment paper!!! Is it safe to use unbleached parchment paper wrapped around the meat and then wrap the parchment paper/meat in tin foil? So it’s meat, wrapped in unbleached parchment paper, wrapped in tin foil? Then put in the freezer… Or should I store the meat in unbleached parchment paper and in plastic freezer bags? What’s the safe way to do it?

    • Aluminium will leach when it’s heated or if it comes into contact with acidic foods. So I wouldn’t worry about wrapping chicken and turkey in foil for the freezer. If you cooked directly on aluminum foil, that’s when I would switch to parchment. 🙂 Hope that makes sense!

  4. I am just wondering whether the parchment paper REALLY protects the foods from leaching. Is there any source for that? Thanks.

      • Thanks for your reply and sorry for my bad English. Yes, I know that the material leaches and not the food. So, don’t you think the only way to get any material on the food is in a directly contact? Thanks

          • There are stainless steel baking sheets available on Amazon. I bought a couple that I like, however I still use unbleached parchment for connivance in clean up 😉

            • Yes, but the stainless baking sheets are not heavy-duty and tend to bend/warp at higher temps.

  5. I’m a Ph.D. student. A search for a paper that I can use as a non-stick paper at about 220 C for my research landed me here. The search for a solution keeps me reading more about food and health related topics.

    So far it seems to me as if one of the followings could be a solution for me; Teflon sheet, unbleached parchment paper, and silicone paper. is this true? Also, I don’t know the smoothness nature of the papers because they are not readily available in Dammam. or probably I have not found the right supermarket or mall. silicone vs parchment paper which one is better in terms of heat resistance and smoothness. which of the two has a better capability of retaining its look or nature after use at high temperature?

    • Are you using these items for cooking? By silicone, I assume you mean silicone mats, such as Silat? Parchment paper can change its look after being used at very high temperatures, but silicone will not. Many unbleached parchment papers are coated with silicone, actually.

    • Teflon is more toxic than aluminum! The safest thing you can do is invest in high quality stainless steel or stoneware baking sheets and then line them with parchment. I highly doubt that parchment is going to act as a true barrier for the leaching of aluminum into food… paper is porous.

      • Agreeing with you on the Teflon. Know any high quality, heavy duty stainless baking sheets with rims? I have yet to find them. The ones I have tried all warp and buckle in the oven. I have two old ones from All-Clad, but they have been since discontinued. From what I have read, parchment paper is a good enough barrier. Silpat baking mats are another option.

        • Chemist here. Just to let you know, stainless steel leaches chromium and high grade stainless also leaches nickel. Not sure if that matters to you, but….

          • Thanks for your insight, Jamie. From what I understand, the only downside to either is if one has a nickel sensitivity or allergy, one’s skin could break out in a rash. But that is if a person has an allergy. Do you have any additional information about side effects to the amounts of nickel or chromium that could leach from cookware? Thanks!

            • Hi Pamela, How about a cookware that leaches nothing, and when I say nothing, I mean NOTHING, nil, nada. A cookware — pots and pans that are 100% inert. Miriam’s Earthen Cookware having tested all types of cookware, metal and ceramic, started making cookware with 100% primary clay. Their cookware is made by hand, and made in the USA from natural clay harvested and tested in the USA. Cookware made from All-Natural clay is 100% inert and doesn’t leach anything. It is what has been used for thousands of years in civilizations both great and small.

              I love their cookware, having been cooking and eating out of it for years now. You should take a look too!

              Check out their website when you can: miriamsearthencookware DOT com

              • I will certainly check them out! Thank you!!

              • Sounds awesome! We cook our turkey in clay and we finally are making amazing turkeys every time!

  6. Hello, I use parchment paper a lot! If it’s still in good shape, I will use the same piece again. My question is, parchment paper is coated or infused with silicone and if you notice it has a smooth texture but after cooking it is dried out. Where has that silicone ( smooth) texture gone? Is it in my food?. That’s my concern.

    • I use parchment paper that is”unbleached” AND does NOT contain a coating or “non-stick” claim. The parchment paper which states “non-stick” is not the healthy product you are looking for.

      • Unbleached parchment paper is often coated with silicone which is an inert material that doesn’t leach.

  7. Hello, I’m a Food Science/Technology grad student, and I came across your article when doing some reading about vegetable parchment paper, among other things. I would like to take a moment to clarify some seemingly unintentional misleading information, or otherwise exacerbated claims (I would also like to add I have an extensive background in organic chemistry, and will readily answer any questions you may have about certain chemicals and their uses).

    “We already consume aluminum whether we like it or not if we eat out or consume processed foods, drink municipal water, use vaccines or antiperspirants. Many (not all) over-the-counter medicines such as antiacids and buffered aspirin, also contain aluminum. Read the product labels to know for sure. This post isn’t intended to cover all sources of aluminum, but rather focus on protecting ourselves from this heavy metal in the kitchen.”

    Currently, there is no process or unit operation in food processing that exposes you to aluminum. Canned foods cans are made from high quality steel. Aluminum beverage cans are the industry standard for their lightweight and excellent strength and barrier properties. All metals are prone corrosion indeed (water, low pH etc), however, all of your canned food products have inner coatings of enamel, LDPE, EVOH, PVC, and many other polymers in layers in order to protect the metal from corrosion. All of these food packaging materials and processes are approved by FDA and carefully monitored and regulated.

    Aluminum is a secondary contaminant as defined by the EPA, with a maximum allowable contaminant content (MCL) of 0.05-.02 mg/L. The research article you posted clearly states that the World Health Organization (WHO) has set the tolerable daily intake of 1 mg/kg body weight /day for aluminum. That means that if you weighed 140lbs, or 63.5 kg, you could safely drink 1270 L of municipal/tap water contaminated with the MCL of 0.05 mg/L of aluminum PER DAY. Most people don’t even drink 1 gallon of water a day – and if they do, it is MOST likely bottled water, which is virtually free of contaminants, as mandated by FDA. Point being, drink all the water you want, you have a higher chance of winning the lottery within the next 35 years than being poisoned with aluminum.

    Vaccines? Please explain or give me sources, I have never heard this and I am not a microbiology or medical expert. Antiprespirants? Yes I believe they do in fact use aluminum salts which block essentially block the pores in your sweat and sebaceous glands, but hey, do you what sunscreen and tooth paste are? Sunscreen is a moisturizing cream that is white because of the addition of Titanium Dioxide, which is white. That is its main purpose: white in order to reflect UV light from the sun. The titanium salt IS THE FUNCTIONAL ingredient in sunscreen. Likewise, the same salt TiO2, is the FUNCTIONAL ingredient in toothpaste. How? It basically grinds the plaque away. Again, these products are well regulated and your risk of an adverse effects is 0.000000000001% – that number I made up, but my point is it is EXTREMELY low risk. You’re more likely to die from texting and driving than from exposure by any element/chemical in a cosmetic or food product.

    Medicines do contain aluminum salts, because it is a very functional element that can potentially coordinate with three of the active molecules in your medication. Which medications? I don’t know. Again, I am not a medical expert, but I am fairly positive any risk of harmful effects FROM aluminum in your medicine is extremely extremely low, virtually – but not quite – zero.

    Dioxins are indeed harmful and carcinogenic, but simply citing the World Health Organization on dioxins does not prove that these are released when parchment paper is heated. Dioxins are a group oxidized organochlorine benzo-derivatives. These are often released during forest fires, burning of household trash, chemical burning, and a product of the bleach pulp making process. Hence, there may be truth to the suggestion of using unbleached parchment paper seeing as to how certain recipes call for oven temperature over 400 degrees Farenheit. I will research this and try to dig up some interesting research articles, if any.

    For more info, consult: Food Packaging Principles and Practice 2nd Ed by Gordon L. Robertson

    • Thank you for your thoughtful response. I appreciate the opportunity to have intelligent dialogue about this and any subject presented on this blog. I respectfully would like to add my opinion about several of your remarks. Aluminum cans most certainly do leach aluminum into the food they are storing, especially if the food is acidic such as soda. I do not respect the US government’s decision that the amount of aluminum that leaches is not of concern. Aluminium is harmful to the brain and I would like to avoid it. http://www.ncbi.nlm.nih.gov/pubmed/8197828 I am not discussing aluminum poisoning or dying from aluminum toxicity, but merely aluminum leaching into food and therefore begin ingested.
      Source for aluminum in vaccines: http://www.atsdr.cdc.gov/phs/phs.asp?id=1076&tid=34
      The dioxins in bleached parchment paper are formed when the paper is bleached, which is why I choose unbleached parchment paper.
      Again, thank you for your contribution to this discussion!

      • I only buy Aluminum free baking powder. If you bake, please check your baking powder.

        • So true! I always call for aluminum-free baking powder in all my recipes. 🙂

    • Hello,
      I’m concerned about the use and safety of all plastic wrap. Just simply having food touch it seems unhealthy.
      Another concern is foil in contact with tomato products…. Like barbecue sauce on foil on the grill or in the oven.
      Share info on these two concerns
      Please

      • You’re right about the foil. When aluminum is heated, it leaches. And it leaches even more when it comes into contact with acidic foods, like tomatoes. SO I avoid aluminum foil unless I put parchment paper in between the foil and the food. No problem to store food in aluminum at room temp, refrigerator or freezer (not acidic foods, though.) I don’t love plastic and it leaches also when it’s heated. I try to avoid it as much as possible and I choose glass storage containers or glass packaging whenever possible.

  8. Desiring to be on the safer side when I freeze food, I wrap food in parchment paper so the food has no direct contact with the plastic freezer bag. Is there any potential risk associated with the parchment paper in direct contact with food in a freezer?

    Thank you!

      • Even if the parchment paper doesn’t specify “unbleached”?

  9. Thank you so much for sharing valuable information in the interest of the welfare of readers! If I may point out a technicality, aluminum is not a heavy metal as the third paragraphs refers to it. But, of course, it is toxic for human consumption.

    • Thank you for your feedback. I do appreciate it. As I understand it, aluminum as labeled a heavy metal is controversial as I have read it labeled as such and not. Technically, you may be correct.

  10. Dear Pamela thank you for your information,- such a help. Can you advise on the use of unbleached parchment paper for use in our newly bought steamer, some recipes call for wrapping in little parcels. With thanks , Isabel

    • Hi Isabel, I dont’ see why you couldn’t use parchment paper in a steamer. Do the recipes call for wrapping little parcels out of aluminum foil? For how long do the parcels steam?

      • I read on the website for Kana brand Bleached parchment ( they use non chlorine bleach On their products )
        They say, That unbleached parchment actually leaches contaminates ….. because it’s Paper is unbleached … And can be very unsafe…causing many health risks …..
        what is your opinion ?
        L

  11. Are you not concerned about the dangers of Silicone?

  12. What do you recommend using in the toaster oven instead of aluminum foil? I used parchment once and it caught on fire!

    • I make a little “pan” with aluminum foil and a piece of parchment inside. Then I fold the edges around so it stays put. There is also parchment-lined aluminum foil that you can buy!

      • I use parchment in my toaster oven all the Tim just make sure it’s flat or tightly warped so the paper isn’t near the coils.. I’ve never had it catch on fire just turn brown. I’ve even baked potatoes tightly wrapped in just parchment.

        • I’ve never had it catch on fire either. All your suggestions are great, thanks!

  13. Oh my gosh! Parchment paper is one of my favorite tools in the kitchen. I love to cook, hate the clean up and unbleached parchment paper is a great helper. Lining my pans with it before roasting anything makes clean-up a snap! And, yes, unbleached paper all the way. I, too, like the If You Care brand.

  14. So informative, thank you Pamela. I’m curious if you’ve ever detected a smell when using silicone mats or baking cups. I sometimes find my food takes on a silicony (kind of like plastic) smell when using my silpats.

    • Actually Naz, I haven’t used a Silpat in so many years. I think they’re a pain to clean for things like veggies or fish or meat. But I have used silicone muffin liners with success and they don’t seem to impart any off smell. I think if oils and fats stay in the mats, that could be the problem. Not sure, though!


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