I know it’s tempting to use a pressure canner for canning. They are so good at doing just about everything in the kitchen effectively replacing a slow cooker, steamer, rice cooker among others.
And as a pressure cooker they perform so great but you should know that pressure cookers may not be the best bet for canning foods.
There are certain types of foods that you might be able to preserve in an electric pressure cooker but not all.
First lets learn a tiny bit about how a pressure cooker works.
- How Pressure Cookers Work Compared to Canners
- Can you use Electric Pressure Cooker for canning?
- What is Food Canning?
- Why food canning is needed?
- Food acidity matters
- How Does Canning Work?
- What is the Safest Way to Can Foods
- All you Need to Know about Canned Foods
- Why Electric Pressure Cookers are not Recommended to Can Food
How Pressure Cookers Work Compared to Canners
Pressure cookers (pressurized cooking pots) cook food with a combination of steam and heat. Most of the cooking power is provided with high heat that develops steam inside the pot. It contains a valve meant to seal the steam and creation of high pressure. It raises the boiling point of liquid inside the cooker and turns the moisture present in food into steam.
Pressure canners are essentially the same except they are larger and better at maintaining the highest temperatures and levels of pressure inside the pot. This is what is needed to safely preserve foods in cans.
Here are a few examples of top pressure canners – note none are electric pressure cookers.
All fruits, vegetables and meat contain water, and cooker is only transferring heat from external source to the food while cooking. As soon as food gets heat, molecular changes happen resulting in cooked food. Basically, the working of pressure cooker depends on the changes resulting from heat and transfer of water molecules.
In order to understand the working of pressure cooker, assume the fact that water boiling at low temperature at higher altitude. It happens because of the lack of enough pressure that makes water boil at low temperature. Water boiling at low temperature makes food to dry out quickly, burn and makes it difficult to cook. It is the reason why food take much longer time for cooking at high altitudes.
However, the opposite technique is applied to work with pressure cookers. It tends to increase the temperature of water and reduces time for cooking. There is no way steam can escape in pressure cooker, there is no water loss and food is cooked without losing any heat. This is the biggest advantage of using pressure cooker that you can quickly cook food saving time and energy. Pressure cookers are not only used for quick cooking but also for canning food.
Can you use Electric Pressure Cooker for canning?
Pressure cookers have certainly been around for a long time and they have made lives easy with reduced cooking time. One can cook anything in pressure cookers such as rice, stew, meat or vegetables. For sure, they have eased our lives as cooking has become a matter of minutes. Restaurants use stove top pressure cooker, and normal pressure cookers have been replaced with the invention of electric pressure cooker.
Despite of all the time saving and quick cooking benefits, the electric pressure cooker is still not the answer for healthy food preservation of low acid foods. High acid foods such as fruits that can be water bathed may be done in an electric pressure cooker in small quantities but low acid foods need a larger, dedicated pressure canner.
What is Food Canning?
Some low acid foods including meat, vegetables and beans are preserved with a canner. The traditional method of canning used water bath and made food hot like boiling water and not suitable for preserving it. With pressure canning, temperature is increased at high level to kill all bacteria for preservation.
It requires placing of jars and containers of food and heating them at enough temperature to kill all micro-organisms that spoil the food. During the canning process, air is driven out and it a vacuum is formed as it cools down. This vacuum prevents any air entering into the food and prevents micro-organisms away.
Why food canning is needed?
It is an art to preserve food, but this art has been fading with the passing time. However, there are still many people who have been indulged in preserving food with canning. Food canning gives high quality food restoring the real taste and flavors, mean while saving a lot of money. There are many reasons why people love preserving food.
Preserving harvest: Gardeners understand the importance of preserving harvest, as they wait for months when their garden start producing fruits and vegetables. Sensibly canning the harvest prevents wasting of food and enjoying it throughout the year.
- Affordable: Canning seasonal food allows you to enjoy food throughout the year. By doing so, you are able to save money and enjoy high quality food around the year.
- Environmental impact: Preserving your own food with canning is a great way to play your role towards the environment. When you have home grown food, there is no need to rush to grocery stores as you can enjoy your canned food. It also helps in reducing packaging waste and reusing canning jars.
- Healthy and quality food: Homemade food is health and tasty. There is no match to quality of homemade food. You can easily carry out canning to enjoy healthy and quality food. This method gives you fresh food without artificial preservatives and harmful chemicals.
Food acidity matters
Before you really start canning your food, you must know about food acidity to avoid high and low heat setting problems. There are two types of foods i.e., low acid foods and high acid foods.
- Low acids foods: Meat, vegetables, and even tomatoes are referred as low acid foods. These foods are lacking the amount of acidity that is needed to prevent growth and survival of bacteria. Clostridium botulinum, home canning bacteria, generate toxins from the spores that result in food poisoning. Botulism spores get a flourishing environment in low acid foods when there is no air, at room temperature and lack of moisture. On the other hand, spores of Clostridium botulinum only last a boiling water bath and are fully destroyed when processed at a temperature of 240 degrees Fahrenheit. Read more – Does pressure cooking kill bacteria? & Does is kill botulism?
- High acid foods: Fruits are included in high acid foods. Whereas, tomatoes with natural acids need lemon juice, vinegar and citric acid to increase their level of acidity for processing and preserving. Foods with less amount of vinegar, pickled vegetable and fermented foods are also called as high acid foods. These foods can easily be processed and canned with boiling water method.
How Does Canning Work?
When talking about food preservation, there are various methods killing bacteria and restoring natural flavors. Here are some two popular methods, you can use to can food.
Water bath canning
It is the simplest method to can food requiring filling of jars with acidic food, covering and boiling them in an open pan until a vacuum seal is formed under its lid. This process forces air out of the food and creates a vacuum giving a perfect acidic environment where bacteria can no longer survive and grow.
You can use this method to can a variety of food such as jams, jellies, pickles and tomatoes. Water bath canning is safe as jars are covered and heated with boiling water and cooked or a specific time.
It is an advance method of canning food requiring you to need to learn skills and possess special equipment. It is suitable for canning vegetable, meat, poultry and seafood. In this method, jars containing food are placed in water inside a pressure cooker and heated up to 240 degree Fahrenheit.
High temperature required for canning is only achievable with pressure cooker. People use pressure canning method because of the presence of Clostridium botulinum, as it needs extremely high temperature to be killed. If high temperature is not maintained, the spores continue to grow, spoiling the preserved food.
What is the Safest Way to Can Foods
People have been using water bath as well as pressure canning methods. But, water bath canning is the most recommended method. Although, there are instructions mentioned on the manual of electric pressure cooker, but pressure canners are specially designed for this purpose. These are heavy pots containing a lid with a vent, safety fuse and pressure gauge.
All you Need to Know about Canned Foods
When you are planning to can food, you need to know basics about equipment used, ingredients to can properly, process to carry our preservation and safety issues. Here is a guide for your ease.
Canning equipment: Pressure canning require you to purchase special equipment, without that you cannot can food. On the other hand, water bath canning requires some inexpensive equipment that is easily available and handy. All you need is a pot, that can hold enough water to cover the jars and leaves some space for boiling water. Other than pot, you need jars and jar lifter. There is an option of buying new as well as old ones, as per your convenience.
When talking about pressure canning, there is an option of buying new pressure cookers or used ones.
Canning ingredients: You should always use fresh food including fruits, vegetable, herbs and spices. It is good if you buy them fresh every time you want to can food. Buying herbs and spices in bulk can help you in saving money.
Canning process: The process of canning is sequential and needs some preparation beforehand such as cleaning jars and arranging them in a row on the counter. You can simply prepare all the ingredient (including herbs and spices), fill the jars with ingredients, wipe them, screw the lids, boil them in water tub, remove and let them cool. Make sure you are satisfied with the seal formed with the canning method.
Canning safety: There is no risk and harm related to canning. All you need is to sanitize cans to be on the safe end. Your ingredients especially fruits and vegetable must be washed and dried.
Why Electric Pressure Cookers are not Recommended to Can Food
There are many reasons that makes electric pressure cooker not suitable to can food, such as:
Temperature: When using a pressure cooker, pressure is more important instead of temperature. But canning is all about temperature. Once pressure cooker reaches require pressure for canning, it cannot guarantee even heat is provided to food inside the jars. Therefore, there is no certainty if canning is taking place properly by killing all the bacteria, as it should be. Just giving an external pressure is not sufficient for canning. It is necessary to make sure air is mixed well with steam, and temperature is lower than the pressure of steam. Moreover, there is need to adjust pressure settings to ensure accurate canning results.
Pressure: One of the biggest concerns using an electric pressure cooker for canning, is the pressure for low acid foods. Canning of low acid food needs to rely on combination of heat and pressure. This combination is crucial during the actual canning process as well as for cooling the canner and jars. Although, heat is turned off, food still remains under high temperature that is good for killing bacteria, but it reduces the cooling time. There is no way of finding out the time when pressure inside the pressure cooker is reduced and cooling has started.
Heat distribution: A balance and a good combination of temperature and pressure is needed inside the canner for proper processing. There is no way to track the actual temperature inside the jars when canning is carried out in electric pressure cookers. All that matters, for canning, is the even heat distribution inside the jars to completely destroy bacteria. Positioning the jars and flow of steam also affect temperature inside the canner.
Spoilage: Using high quality products, fresh ingredients, correct positioning of jars and right procedure gives ultimate results of can food. However, canning failures are seen in form of food spoilage, when temperature is not adjusted inside the pressure cooker.
So what’s the deal here? If they both work in basically the same way, can an electric pressure cooker be used for canning in the place of a pressure canner?
Well, yes and no. Or, more accurately, it depends on the precise model you’re talking about.
On the whole, pressure cookers are not suitable for canning. This can either be for very practical reasons such as the fact that they are typically smaller appliances and so are unable to hold jars in the same way as a pressure canner, or it can be for important safety reasons: some pressure cookers just will not be tested to work in the canning process, and you should exercise caution before trying to can with a device that isn’t intended for the task.
Always follow the manufacturer’s instructions and, when in doubt, you should be able to contact them for advice in this regard.