Beware The “Lasagna Cell”: How Some Metals Can Ruin Your Meal And When Even A Non-Reactive Pan Can Be A Hazard

By:

Meathead

Beware of reactive pans and be afraid of the lasagna cell.

Reactive pots and pans made of aluminum, cast iron, hammered steel, brass, or copper can react with some chemicals in foods, especially the acids and salts in sauces, brines, and marinades, and they can undergo a chemical reaction and create off flavors, and in rare cases, are toxic.

Non-reactive containers made of stainless steel, glass, porcelain, and enamel will not change when subjected to foods. Plastic is also non-reactive, but it can also absorb flavors and be stained by sauces.

Perhaps the most extreme example is the lasagna cell. Lasagna lovers often are appalled when they open the fridge or oven and find holes in the foil on top of the pan and black spots on their dinner.

They are not alone. Cooks who put meat in a marinade in a steel pan and cover it with aluminum foil overnight can wake up the next morning horrified to see that the foil has holes in it and cry for help in our comments section.

Sometimes barbecue cooks who use the “Texas crutch“, a technique of wrapping their meat in aluminum foil to combat a phenomenon known as “the stall” (when evaporation from the meat cools its surface and stops it from cooking), are shocked to find holes in the foil and juices leaking out when they use a steel pan and foil for the crutch.

What has happened is an electrochemical reaction called galvanic corrosion, dissimilar metal reaction.

For a better understanding of the process, I asked the AmazingRibs.com science advisor Prof. Greg Blonder. He explained that the cook has essentially created a small battery, a cell, and the electric current running through it has etched away one of the battery’s electrodes. Huh?

“All batteries consist of two electrodes, the anode and the cathode, separated by a conducting material called an electrolyte. The electrolyte carries electrons from one electrode in one direction, and waste products scavenged from the other electrode, in the other direction. A car battery has a negatively charged lead electrode (the cathode) on one side, positively charged lead oxide is the second electrode (the anode), and sulfuric acid is the electrolyte”.

So how does a pan of lasagna become a battery? “An acid such as vinegar or tomato sauce and electrically charged atoms like salt form the electrolyte. Aluminum foil is one electrode, and the pan, often steel or different alloy of aluminum, is the second electrode. This causes the aluminum foil to pit and dissolve, and you shouldn’t ingest gravy filled with metal ions”.

Blonder says “A corrosion cell is possible across two different brands of foil, between aluminum foil and a steel baking pan, and even inside a aluminum foil pouch if the acidity or temperature varies across its length. Any chemical activity difference produces an electrical current and then corrosion.”

The same thing can happen in a pan of marinade or brine. It can happen in the fridge, but the reaction occurs faster at oven temperatures. Blonder says “I always cook lasagna in a pyrex pan, and store in the fridge covered with saran first, and foil on top. Otherwise the foil will be pitted wherever it touches the tomato sauce. You may not always notice the small holes unless you hold the foil up to the light”.

And he warns the barbecue cook, “You can also form a battery between an aluminum foil wrapped piece of meat, the drippings, and a stainless steel thermometer cable. Weird but true”. Can you damage the thermometer probe by contact with foil? “Very unlikely” he says. Stainless is covered with an inert chrome oxide layer, which protects it from rusting and damage. No stain, no pain.” Click here for more on stainless steel.

What about the foil in contact with grill grates? “Generally, the grates are pretty dry when hot and will not set up a corrosion cell even if the foil leaks juices” he says. For smoking, the safest solution is to crutch in a lightly closed plastic Reynolds oven bag, butcher paper, or parchment paper, then foil. Blonder warns “Never cook in Saran Wrap. It is not designed for continuous use at boiling temperatures.”

Another option is cooking on an insulated grate such as teflon frog mats or enameled coated grates.

Related articles

Published On: 8/29/2012 Last Modified: 3/10/2021

  • Meathead - Founder and publisher of AmazingRibs.com, Meathead is known as the site's Hedonism Evangelist and BBQ Whisperer. He is also the author of the New York Times Best Seller "Meathead, The Science of Great Barbecue and Grilling", named one of the "100 Best Cookbooks of All Time" by Southern Living.


If you help us, we’ll pay you back bigtime with an ad-free experience and much more!

Millions come to AmazingRibs.com every month for quality tested recipes, tips on technique, science, mythbusting, product reviews, and inspiration. But it is expensive to run a website with more than 4,000 pages and we don’t have a big corporate partner like TV network or a magazine publisher to subsidize us.

Our most important source of sustenance is people who join our Pitmaster Club, but please don’t think of it as a donation. Members get 21 great benefits. We block all third-party ads, we give members free ebooks, magazines, interviews, webinars, more recipes, a monthly sweepstakes with prizes worth up to $2,000, discounts on products, and best of all a community of like-minded cooks free of flame wars. Click below to see all the benefits, take a free 30 day trial membership, and help keep this site alive.


Post comments and questions below

grouchy?

1) Please try the search box at the top of every page before you ask for help.

2) Try to post your question to the appropriate page.

3) Tell us everything we need to know to help such as the type of cooker and thermometer. Dial thermometers are often off by as much as 50°F so if you are not using a good digital thermometer we probably can’t help you with time and temp questions. Please read this article about thermometers.

4) If you are a member of the Pitmaster Club, your comments login is probably different.

5) Posts with links in them may not appear immediately.

Moderators

  Max

Click for comments...

illustration of galvanic corrosion experiment

To demonstrate galvanic corrosion, Blonder filled two steel muffin tins halfway up with unadulterated pureed canned tomatoes, which is acidic. Then he suspended a 1/2″ wide strip of aluminum foil above each cup and lowered the ends of the foil into the sauce. One strip was “isolated”, that is, not directly connected to the steel. The second strip was connected to the steel cup with a short length of wire. The wire is just like the aluminum foil touching the steel pan.

After cooking in a 325°F oven for an hour, he removed the strips. They were both unaffected. He then added 1/4 teaspoon of salt to each cup, and repeated the experiment. This time, the isolated foil remained unaffected but the connected strip etched completely through at the surface, disconnecting a tab of foil (at right).

He explains that “The foil severed at the surface because the galvanic current is most concentrated at this point and the temperature is a bit higher than lower in the sauce. Once the current enters the tomato sauce, it spreads out and dissipates.

Close examination of the disconnected tab showed it was riddled with holes (shown with backlighting, below).

Spotlight

These are not ads or paid placements. These are some of our favorite tools and toys.

These are products we have tested, won our top awards, and are highly recommend. Click here to read how we test, about our medals, and what they mean.

Use Our Links To Help Keep Us Alive

A big part of this site is our unbiased equipment and product reviews. We love playing with toys and we have no problem calling them the way we see them. Some companies pay a finder’s fee if a reader clicks a link on AmazingRibs.com and buys a product. It has zero impact on our reviews, zero impact on the price you pay, and the sites never tell us what you bought, but it has a major impact on our ability to keep this site alive! So before you buy, please click our links. Here’s a link that takes you to a page on Amazon that has some of our favorite tools and toys: https://tinyurl.com/amazingribs


Our Favorite Backyard Smoker

The amazing Karubecue is the most innovative smoker in the world. The quality of meat from this machine is astonishing. At its crux is a patented firebox that burns logs above the cooking chamber and sucks heat and extremely clean blue smoke into the thermostat controlled oven. It is our favorite smoker, period.
Click here for our review of this superb smoker


If you have a Weber Kettle, you need the Slow ‘N’ Sear


The Slow ‘N’ Sear turns your grill into a first class smoker and also creates an extremely hot sear zone you can use to create steakhouse steaks.
Click here for our article on this breakthrough tool


Digital Thermometers Are Your Most Valuable Tool And Here’s A Great Buy!

A good digital thermometer keeps you from serving dry overcooked food or dangerously undercooked food. They are much faster and much more accurate than dial thermometers. YOU NEED ONE!
Click here to read our complete review



Surely you know somebody who loves outdoor cooking who deserves a gift for the holidays, birthday, anniversary, or just for being wonderful. There he is, right in the mirror! Here are our selections of best ideas, all Platinum or Gold Medalists, listed by price.

Click here to see our list of Gold Medal Gifts


Grilla Pellet Smoker proves good things come in small packages

We always liked Grilla. The small 31.5″ x 29.5″ footprint makes it ideal for use where BBQ space is limited, as on a condo patio.
Click here for our review on this unique smoker


Compact Powerful Sear Machine For Your Next Tailgater


Char-Broil’s Grill2Go x200 is a super-portable, fun little sizzler made of heavy, rust-proof cast aluminum. The lid snaps shut. Grab the handle and you’re off to the party! Char-Broil’s TRU-Infrared design produces searing heat while reducing fuel consumption. A 16 ounce LP gas canister is enough to keep you flipping burgers for hours.

Click here to read our detailed review and to order


Heat Resistant Gloves With Extra Long Sleeves Hold The Hot Stuff

If you’re using oven mitts at the grill, it’s time to trade up. Say hello to these suede welder’s gloves. They’re heat resistant enough to handle hot grill grates, and flexible enough to handle tongs. The extra long sleeves even let you reach deep into the firebox to move hot logs without getting burned. Our Fave.

Click here to read our detailed review

Click here to order from Amazon