Can I use a glass mason jar or an empty tin can as a DIY cooking pot?

Question

I'm talking about a small gas or alcohol stove, for example like this:

Images from: https://www.rei.com/blog/camp/diy-how-to-make-an-alcohol-stove-from-soda-cans

Since the stove is DIY, I was thinking how to make the pot DIY, too.

If I'd use a glass mason jar instead of a cooking pot - would the glass shatter? After all, glass cookware does exist and test tubes are being held directly into the flame of a burner, too. But maybe that's just a special kind of glass?

What about using an empty tin can? What metal is that? Is that material safe for food? I read about a plastic lining on the inside that might turn out problematic. But apparently I can just "burn it off"?

Any other ideas?

The reason for my question (and subsequently a constraint for any answers) is my very low budget. I do have pots at home, but they are very heavy and... well, I need them at home. Obviously, there are camping cooking pots that would work very well, but they are expensive.

I'd appreciate your insight. Thank you very much.

Answer 1

Glass labware is borosilicate glass, commonly known as pyrex. Glass cookware is often also borosilicate, but the name "pyrex" is also used for tempered glass products, at least in the USA. Lab beakers are much thinner than cookware. This makes them better able to resist thermal stress, which is caused by the temperature difference between inside and out.

Regardless of whether you could cook in a mason jar on such a stove, I wouldn't. You've just made a nice light stove - why carry something so heavy to cook in? It's also something that's likely to be totally destroyed if dropped on a rock, leaving you with no cooking pot.

My DIY alcohol stove and its windshield/pot stand fit inside an enamel mug - that's my cooking pot (I ordered a titanium mug but the dimensions were misleading and the stove doesn't fit). These can be quite cheap.

With food cans you have to be a bit careful. Many (especially acidic) foods use cans with a plastic lining, which can take boiling water temperatures but not much more, and may not do well if reused repeatedly. People talk about burning it off, but the smoke and residue are quite likely to be toxic - and there's no way to be sure.

Aluminium drinks cans, cut open, are a bit too easily squashed to pick up full of boiling water, even if you do something about the sharp edge.

Answer 2

According to Anne Radcliffe's article Mason Jars Are All the Rage But Here's Why You Should NEVER Cook in One at yummymummyclub.ca -- the title alone suggests "no, don't do it"

Essentially, canning jar glass cannot handle the sudden temperature changes found when baking. I'd say that, if used on a stove burner, the temperature changes would be even more sudden, but I'm no expert on that.

Glass expands when heated, like many materials. When it cools, it contracts. Objects that are heating or cooling usually do so unevenly due to a number of factors, including what may be touching it or even just the flow of air around it. But what many people don't know is that this causes the material stress.

To some degree, glass can handle the stress placed on it by heating and cooling, as long as it doesn't happen too rapidly and from extreme hot (such as an oven) or cold (like a freezer). Your glassware doesn't usually break when it comes out of the dishwasher and finishes cooling down in the cupboard... but it will, if you take it fresh out of the dishwasher and put it under the tap for a cold drink. Cracking from the sudden temperature change is called thermal shock.

But there are different types of glass, and different types of glass have different strengths. The different strengths come from how the glass was made and what it was made from.

Pyrex, which is oven-safe, is made of tempered glass--also known as safety glass. But even Pyrex has its limitations, and it is still vulnerable to thermal shock. If you've ever set a hot Pyrex dish on a cold surface, you may have had to duck for cover. Like all safety glass, in conditions that cause it to break, it shatters explosively into many small, blunter - mostly harmless - fragments, designed to help protect you from getting cut badly.

Mason jars are commonly made of annealed glass. When annealed glass fractures, it will shatter into irregular, very sharp pieces and miniature shards. This can cause you minor injury if you're holding it at the time, or it can crack small fragments of glass into your food. You should discard any food or drinks contained in a glass in which a crack has formed. When you use mason jars for canning, you should never pour hot food into a cool jar.