When conserving food in jar, why is the jar turned on its head when cooling?

I am talking about the process, where you cook food, for example, a vegetable and conserve it in a jar. The jar can then be stored in a non-refrigerated area.

Many recipes include adding salt, vinegar or some other preservative to the jar.

The process I am talking about only uses water and heat.

I am trying to do this for a third year, each time I have multiple jars going bad.

Most tutorials include the filled jar being heated up (in a water bath) and then (or even while heating) being turned on its head and being let to cool in this position until it is ready to be stored away.

Most tutorials mention, that there is a vacuum being formed, and the jar being on its head somehow helps the process.

It looks something like this:

The way I understand it is that during the heating process the air in the jar expands and escapes the jar, which reduces the air.

What I don't understand is why this is necessary, obviously there is no perfect vacuum and why the jar needs to be turned on its head?

Also, since the jar is cooked and all bacteria killed, why is air a problem?

food-preservation

Best Answer

Generally turning a jar upside down after filling is a alternative to a proper hot-water bath, not an addition to it. This is known as the inversion method, and is used by many cooks of jams, jellies, mustards, and other very-low-risk canned foods.

The idea of inversion canning is that, by forcing the air in the jar through the hot liquid, you can kill and bacteria in the air (and on the inside of the lid). It is not considered safe by experts, because there are numerous ways that bacteria can survive the process.

If you are doing "proper" canning, that is heating up the lidded jar to 85C or above, the sealing, inverting the jars is in fact a bad idea as it could result in liquid preventing the jar lid from sealing properly. The Ball jar corporation says “Do not invert. move or store jars while cooling, as this may cause seal failure.” At the least, it's unnecessary.

Pictures about "When conserving food in jar, why is the jar turned on its head when cooling?"

When conserving food in jar, why is the jar turned on its head when cooling? - Free stock photo of almond milk, almonds, bottle

When conserving food in jar, why is the jar turned on its head when cooling? - Clear Glass Jar With Brown Liquid on Brown Wooden Table

When conserving food in jar, why is the jar turned on its head when cooling? - Green Fruit and Veg Smoothie Served in Jar with Straw

Are you supposed to turn the jars upside down when canning?

What is this? Ball recommends against it for seal quality reasons. They say, \u201cDo not invert, move or store jars while cooling, as this may cause seal failure.\u201d For any other type of canning (besides jams and jellies)\u2013vegetables, pickles, tomato sauces, fruit, etc.

Why store jars upside down?

She said: \u201cA great tip to stop food in jars from going mouldy once you open them is to store them upside down in the fridge. \u201cIt seals them and stops them from going bad, which saves you time and money.\u201d

Why is head space important in canning?

Headspace is the distance between the surface of food and the underside of the lid. Leaving the specified amount of headspace in a jar is important to assure a vacuum seal. If too little headspace is allowed the food may expand and bubble out when air is being forced out from under the lid during processing.

Why do you store pickles upside down?

Think of it like an hourglass that will keep items submerged in their juices but can be turned upside down so the liquid collects on the bottom and your pickled onions, jalape\xf1os, or whatever else you have in there is exposed and easier to pick up then fishing in a jar.

Preserving : 11 Tips you MUST know !

More answers regarding when conserving food in jar, why is the jar turned on its head when cooling?

Answer 2

I agree with the above response, in that it is safer to sterilise by immersing the entire jar in boiling water. However, in answer to your question, the idea is to sterilise the lid and inner rim of the jar after sealing by getting them to >85°C for 10 mins. This only works if you make sure you bottle your preserve when far hotter than 85°C so that it takes longer than 10 mins to drop below that temp. Assuming you have steam or oven sterilised your jars before bottling, you are only killing the stray bug that floats into the jar in the brief moment when you open it and pour in the preserve before replacing the lid.

Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.

Images: FOX, cottonbro, ROMAN ODINTSOV, Lisa