78
votes
What is the code for the rings stamped on the top of canned food?
There’s no hidden code in the rings, they are just there to stabilize the thin metal.
A flat sheet is weaker and more flexible than one with ridges - the same reason why roof and wall metal is usually ...
64
votes
Accepted
How can I get a very thick or viscous paste (e.g. caramel, ganache, thick mayonnaise) into small-necked squeeze bottles without heating it up?
What about a piping bag? Fill the bag with a spatula, pipe into the bottle.
42
votes
Does cooking food inside a pressure cooker and then leaving it locked preserve it similar to canning?
When you take the pressure cooker off the heat, it's filled with high-temperature, high-pressure steam. As it cools, that steam condenses, leaving a vacuum. Pressure cooker valves are designed to ...
38
votes
Accepted
Why is a pressure canner needed when canning?
Physics stops you from heating up liquids that consist of mostly water to temperatures above (roughly) 100 C.
The temperature of your heating element can be set higher, but neither the temperature ...
36
votes
How can I separate the lid from a can that has a pull-tab/ring without flinging food everywhere?
For most of the removal, leverage rather than brute force will give more control, so you don't accidentally pull the last bit off.
At the end while pulling gently on the ring, rock the lid from side ...
34
votes
Accepted
What is the process of storing food in toothpaste'ish tubes?
Tubes like that are assembled with the bottom open (so at that point it's a cylinder, closed at the cap end), filled, and then folded and heat-sealed at the bottom. The filling is done with a rigid ...
33
votes
Accepted
Repackaging shelf-stable products
Exposure to germs is the problem, once you open these they are exposed and the clock starts. If you vacuum seal you are vacuum sealing the germs in with the food, and not taking steps to kill the ...
27
votes
What is the code for the rings stamped on the top of canned food?
Actually, there can be encoded information stamped into the can ends, but it's probably not what you're thinking it is.
The presses which make the ends from sheets of metal usually contain multiple ...
26
votes
Accepted
Canning with candles
The short answer is: No.
The more elaborate answer is that certain bacteria are anaerobic and food needs to be heat treated to ensure it can be safely stored. Especial mention: Clostridium botulinum ...
24
votes
Accepted
Does canned tuna contain preservatives?
The preserving effect of canning is based on
removing all bacteria and fungi (normally present at least to some extent even in perfectly safe food) by a combination of heat and pressure over a ...
24
votes
Canning tomato sauce for the refrigerator
As you state, you have not followed any canning procedures, so you don't get any more storage time than the standard recommendation. Glass vs plastic doesn't matter. So, I would just recommend ...
24
votes
Does this tinned food need to be cooked?
All tinned foods which are not dry (like flour or coffee grounds) have been sufficiently cooked and are safe to eat directly after opening. Once opened, leftover contents should be treated like any ...
24
votes
Can I cook with the olive oil from canned sardines?
Yes, you can use the oil for other purposes, although due to the strong fish aroma and taste it would probably best be used only in a fish dish. I frequently use the oil from anchovies to fry onions ...
23
votes
Can you can items using a deep frier instead of a pressure canner?
In theory, it may be possible to kill all of the contaminants inside your jars using a deep fryer. However, I would not call it "safe," since there is possibly more risk of getting hurt from ...
20
votes
Accepted
What to expect from canned bear meat?
Canned foods are by their very nature cooked once they're in the can. That's how they keep so well. It is possible to grill canned meat if you dry it first, and it may benefit from a little browning ...
20
votes
Accepted
Why does processed meat contain preservatives, while canned fish needs not?
These are two different ways to preserve food.
The canned salmon was boiled and then sealed into a can while it was still boiling sealed into a can and boiled under a specified combination of time ...
20
votes
Can you save canning jars after you've realized they've been improperly sealed for a month?
Food spoils, glass doesn't, so as long as the jars are cleaned thoroughly they are perfectly safe to use. If you are very concerned then you could sterilize them as well using a bleach solution, or by ...
20
votes
Accepted
Can you can items using a deep frier instead of a pressure canner?
That’s a nice thought, but physics make it impossible. It’s not about the external temperature, but about internal temperature, in the jars.
The contents of the jar are (hugely simplified) water, ...
19
votes
Does this tinned food need to be cooked?
As people have mentioned, canned meats are cooked as part of the canning process, so it’s safe to eat as is... but it’s not always ideal to do so.
In many ways, it’s like a chicken hot dog right out ...
18
votes
Accepted
How prevalent was foodborne botulism before stricter food safety guidelines?
Summary:
It's impossible to give a good statistical answer to this question, since historically botulism was associated with only certain foods, and diagnosis was mostly based on symptoms occurring ...
16
votes
Accepted
What do to with cans that you just dented?
If you just damaged previously unharmed cans and they don’t show signs of leakage, the cans should be perfectly safe, even if you store them at room temperature.
The US Department of Agriculture ...
15
votes
Accepted
Should I throw away a jar of olives that fizzed and bubbled upon opening?
Short answer:
Yes, throw it away.
Long answer:
Bubbling, fizzing, pressure etc. indicates some kind of microbiological activity that is unwanted for properly canned food - canning should eliminate ...
15
votes
Accepted
Should I sterilize new canning jars?
You should sterilize your jars and lids before every use.
The dust that gets on them between uses and even in the box is enough to warrant sterilizing.
It doesn't take long. Running them through a ...
15
votes
How can I get a very thick or viscous paste (e.g. caramel, ganache, thick mayonnaise) into small-necked squeeze bottles without heating it up?
Edited: Concerns were expressed about such items being suited for food use. I've added comments in the text on "Food Grade" items plus a note at the end.
How can I get a very thick or viscous paste ...
14
votes
Does cooking food inside a pressure cooker and then leaving it locked preserve it similar to canning?
The (old-fashioned Central European) pressure cookers I've worked with have outlet valves which in pressure cooking position let gas out (at defined pressure), but not in. These cookers do have an ...
13
votes
Accepted
Does this tinned food need to be cooked?
From Grab Grocery:
Precooked beef luncheon meat with the addition of chicken essence in 340g preserved cans. Robert beef luncheon meat is a wholesome meal cooked and slaughtered as per halal dietary ...
13
votes
How can I separate the lid from a can that has a pull-tab/ring without flinging food everywhere?
This answer is not ideal, as it avoids the use of the pull-tab altogether:
Use a regular can opener instead. No flinging of food involved!
13
votes
Accepted
Is this process of canning jars safe?
No, it is not.
Diced tomatoes and tomato sauce can be low-acidity foods, Nearly all recipes call for adding an acid. Without adding an acid and proper processing of jars, you risk botulism and a few ...
12
votes
Why does processed meat contain preservatives, while canned fish needs not?
Canned salmon is sterilized. Sterilization uses heat to render a product safe. Cured hams are preserved with salt, and nitrites in some cases. Some hams are also cooked. Furthermore, some fish is ...
12
votes
Accepted
For Pressure Canning, can I use any other jar than Ball’s Mason Jar?
The important part of the system are the lids. The ideal lids are the Mason-type (no matter which company produced them), with a flat top and a separate side piece with thread.
Another type that ...
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