Sealing canning jars in hot water bath

An easy guide to water bath canning for beginners – this at-home canning technique is perfect for preserving jams/jellies/preserves, fruits, pickles, and tomato products for up to a year of locked-in freshness and flavor!

I won’t lie – when I was first introduced to water bath canning as a method of canning food, I was utterly overwhelmed. You hear all these stories of canning gone wrong, botulism, exploding jars, items refusing to seal – and it’s enough to put anyone off. But then I started to read more into it and spent time researching. Ultimately, I became fascinated with learning how to water bath can!

Having compiled a year+ of research and personal experience, the below is my ultimate hot water bath canning for beginners guide. This includes what is water bath canning, how it works, the home canning supplies you’ll need, what you can safely water bath can, and my top tips for the best results every single time!

Top Tip: This guide has a LOT of information. If you’re looking for advice on a specific topic, press CTRL+F / CMD+F on your keyboard and type in your keyword.

Table of contents

• What is Water Bath Canning?
  • How does canning preserve food?
  • What Are High Acid Foods?
    • Some examples of high acid foods include
      • *For all tomato products, you’ll need to add an acid. The general guidelines are:
• Home Canning Supplies Needed
  • Optional Extras
• Top Tips for The Best Home Canning Results
• How to Water Bath Can: Step-By-Step!
  • Step 1: How to sterilize canning jars and countertops?
  • Step 2: Fill and close the jar
  • Step 3: Process the jars
  • Step 4: Remove the jars from the pot
  • Step 5: Leave to cool and store
• The Hot Water Bath Canning Steps Summarized
• FAQs
• More How-To Guides

What is Water Bath Canning?

Home canning (also called bottling) refers to the process of preserving fresh, ripe, in-season foods (at their highest quality) for a cost-effective method of locking in the freshness for long-term storage. There are two home canning methods, including pressure canning and water bath canning. The methods ensure that fruits, veggies, and meats are packed into separate sterilized jars and then go through a heat process. This process not only helps kill harmful organisms but also provides a vacuum seal that slows down the spoilage process.

The two methods of canning vary depending on what you want to preserve: with pressure canning working best for low-acidity foods (veggies and meats), and water bath canning working best for acidic foods – like pickles, jams/jellies/preserves, certain fruits, tomato sauce, salsa, etc.

For this post, we’ll be exploring the water-bath canning method (also called boiling water bath canning and hot-water canning). This is the easiest method of canning, processing jars in boiling water. The result is a vacuum seal and months (if not a year+) of locked-in freshness.

How does canning preserve food?

As we know, food spoilage is primarily caused by oxidization and bacteria (including molds, yeasts, etc.). Unfortunately, no matter how clean you are, many bacteria/germs are naturally occurring in the environment. Also, many of the items we hope to preserve make for the perfect environment for that bacteria to thrive.

Luckily, hot water bath canning places the jars in a boiling water bath (at 212ºF/100ºC) for a specific processing time to destroy the harmful microorganisms. At the same time, we’re sealing the jars to make sure that no new air (and germs!) can re-contaminate it. Voila!

What Are High Acid Foods?

This is possibly the most important question to ask yourself to begin, as different foods will require different preservation methods. When we talk about high-acid foods, we’re referring to foods with a pH level of 4.6 or lower.

For some ingredients that aren’t naturally at the correct pH level (like tomatoes), recipes have you add acid (though isn’t possible with everything). This is usually in the form of citric acid, lemon juice, or vinegar, to reach the correct level before canning.

Why is this important? Because water bath canning can only heat foods to boiling point (212ºF/100ºC). However, low acid foods require higher temperatures (around 240ºF/116ºC) to adequately kill harmful bacteria and eliminate the risk of botulism.

Some examples of high acid foods include

• Jams/Jellies and preserves,
• Tomatoes – whole, sauce, juice, puree, etc. (usually with added acid*),
• Relish (with added acid),
• Salsa,
• Pickles,
• Fruits – including apricots, apples, berries, peaches, pineapple, plums, pears, rhubarb, strawberries, etc.

And what are low-acid foods I (don’t) hear you asking? Things like meats, soups, vegetables, etc. Any items like this MUST be preserved using the pressure canning method and NOT hot water bath canning. If you’re feeling confused about any ingredient, refer to the USDA’s Guide to Home Canning.

*For all tomato products, you’ll need to add an acid. The general guidelines are:

Per each pint of tomatoes, add one of the below:

• 1 tablespoon bottled lemon juice (which has a consistent pH level),
• 2 tablespoons vinegar,
• ¼ teaspoon citric acid.

You may need to add a little sugar to the tomatoes to balance the acidic flavor.

Tip: When adding extra acid to canning foods, you don’t necessarily have to mix it into your food. In many cases, you can add the acid directly to your jars before filling them.

Home Canning Supplies Needed

• Jars: the most popular jars for canning in the US are mason jars (in the UK, Kilner jars). However, you can also use rubber-top clip jars (though I don’t often use this type). There are two main types of jars: regular and wide mouth. The latter is easier to fill but more expensive, so either will work. I recommend collecting reusable jars in several sizes: 4 oz, half-pint, pint, pin-and-a-half, and quart jars.

Not all jars are safe for water bath canning, though (i.e., some are freezer specific or decorative). Ensure you use jars that are marketed to withstand the boiling water bath process.

• Lids: there are two main types of lids that I like to use. The first is a reusable lid with dimple. When you’ve achieved a successful vacuum seal, it will no longer move up and down or make a popping noise. Alternatively, you can use canning lids that come with two pieces (a band/ring and flat lid bit). The only downside is that, while the rings are reusable, the actual lids are not. Though you can purchase reusable canning lids now, too (phew!).
• Canning tongs: it’s best to use secure-grip jar lifting tongs, which are like extra-large tongs with rubber at the bottom that grip the jar, so it doesn’t slip (which could ruin the canning process and/or splash hot water on yourself). Alternatively, you could use other types of kitchen tongs, but it won’t be as secure.
• A large pot and rack: there are specific water-bath canners available, which are essentially just a large pan with a rack (though they sometimes contain an altitude gauge, which is helpful to know which canning zone you’re in). Alternatively, you can use a large, heavy-bottomed pan (a large stockpot, 16+ quarts capacity is best) with a lid. You’ll also need a heat-proof wire rack or a silicone trivet to fit the bottom of the pan. It is needed so the cans aren’t directly on the bottom of the pan getting direct heat from the burner.
• Kitchen towels: Okay, kitchen towels or micro-fiber cloths aren’t canning specific, but very handy when canning. You can set your hot jars on one and use them to wipe away spills on the side of the lip before sealing, etc.

Optional Extras

These home canning supplies aren’t necessary but can be helpful.

• pH strips: specifically for foods where you’re having to add extra acid to reach the correct pH level. You can buy pH strips to make sure that they’re below 4.6.
• Funnels: home canning relies on a 100% sterile environment. To avoid mess when filling your cans, I recommend using canning funnels. Use funnels made from non-reactive materials (silicone, plastic, or stainless steel). ALTERNATIVELY, you can use a non-reactive ladle.
• Bubble remover: you can use specific tools to remove air bubbles from your filled jars (also called a “headspace tool”). However, I’ll be honest – I use a chopstick, plastic/wooden knife, skewer, or handle of a silicone spoon.
• Magnetic lid wand: a magnetic lid wand can pick up single lids to place on your jar before sealing with the ring. That way, you don’t have to touch them and accidentally touch the inside of the lid.
• Citric acid: some foods need additional acid to help bring the pH level to the correct number. While you can use vinegar/lemon juice, citric acid is another option that’s easy to have on hand at all times.
• Timer: you can use the timer on your phone if you don’t want to purchase a separate one. But make sure you have access to an accurate timer, and there are several stages where you need to time things while hot water bath canning, including the processing time and the 5 minutes resting time after.

Top Tips for The Best Home Canning Results

• Check the jar rims before using: to check for any chips/nicks around the lip that could compromise the sealing process.
• Make sure to sterilize EVERYTHING: the enemy of home canning is bacteria. So make sure to follow the steps below to ensure all the tools AND the workspace are thoroughly clean. There is an exception, though – screw band canning rings don’t technically need sterilizing as they will never come in contact with the food.
• Ensure the jars and lids are 100% dry before filling: as any moisture can cause faster food spoilage. 
• The jars must be hot before adding to the canning pot: if they aren’t, they can become “shocked” from the quick temperature change and crack/break. Follow the hot water bath canning method below for all the tips and tricks.
• Make only as much food as you can fit in the canner: if you end up with any extras that won’t fit, you can refrigerate those jars and eat the content in their non-preserved shelf-life (usually 3-5 days).
• Measure the headspace: the exact amount is variable though the rough guideline are ¼ inch (0.5 cm) for jams/jellies/marmalade/relish and ½ inch (1 cm) for fruits/pickles/ tomato products. Don’t leave too much headspace, though, as it can form a “false seal” and can become unsealed over time.
• Remember, the processing time is variable: this home canning for beginners guide contains all the best information for newbie home canners. However, it’s important to note that the processing time for your food item is variable based on the altitude, hot vs. raw packing method, and item and size of jar you’re canning. Please refer to the National Center for Home Food Preservation’s guide to ensure that you’re using the correct processing times and procedures.
• Leave the jars untouched for 24 hours after processing: technically, some recipes will only require 12 hours, but I always leave them for the total 24 hours. During this time, the lids will properly seal, dry, and cool down. If you touch them beforehand, you may accidentally create a “false seal”, where they appear properly sealed (but aren’t!).
• Remove the lid rings when storing: they can also cause a false seal. When storing without the rings, you’ll be able to see if the lid is at all loose (or comes off) when picking it up before enjoying the food (if so, then DON’T eat it).
• Follow the recipes: home canning IS an exact science, so follow recipes (especially those provided by the National Center for Home Food Preservation).

How to Water Bath Can: Step-By-Step!

Step 1: How to sterilize canning jars and countertops?

To clean the working area, I first like to wipe the countertop and stovetop with soapy water.

At the end of the canning process, the jars must stay on a clean surface and be left undisturbed for 24 hours. So, keep this in mind if you plan on using kitchen counter space as it may impact your cooking ability for the following day.

Then, it’s time to sterilize the tools (jars, lids, tongs, pot, inner rack, funnel, etc.). To do so, start by washing the items in hot, soapy water. Then, rinse well and place the jars into boiling water – this will help to keep them warm until they’re filled (so they aren’t “shocked” when transferred to the canning pot and crack) – or for at least 10 minutes.

The lids and extra tools don’t need to be boiled, just place them in a container and pour over some of the boiling water for the pot, then transfer them with clean tongs to a clean towel to thoroughly dry.

When they’re ready to fill, you’ll need to use a clean kitchen towel to dry the inside of the jar THOROUGHLY before adding the food.

Step 2: Fill and close the jar

Once the jars are ready, you can fill them with your food of choice. Make sure to leave the correct amount of headspace. To avoid messy spills, use a funnel.

Once the jars are filled, make sure to eliminate any air bubbles, as these will impact the shelf life and can increase the headspace, and cause a “false seal.” Either use a bubble tool or a sterilized chopstick/plastic knife to press into the corners and anywhere bubbles may be. You can also lightly tap the jar against your countertop to bring any air bubbles to the top of the jar.

Depending on the product, you can add extra protection for the home-canned food with a thin layer of olive oil. Then wipe the lip of the jar with a clean tea towel/napkin. Finally, close the jar until finger-tight (securely screwed until the point of resistance, but not too tight that air can’t escape during the processing).

Step 3: Process the jars

Meanwhile, as you were filling the jars, place the rack inside your canning pot and fill the pan halfway, bringing the water to a boil (remember that adding the cans will cause the water to rise, so you don’t want to overfill it at this point).

To test exactly how much water you need for your pot before using it for the first time, you can fill your jars with water, place them in your pot and then add enough water to cover the jars by at least an inch. Then remove the jars and see how much water is in the pot. That’s how much you’ll need to add every time! It’s a good idea to boil the kettle simultaneously, though in case you need a little extra water during the processing.

Once the water is boiling, use the canning tongs to carefully place the jars inside the boiling canning pot, ensuring they remain vertical the entire time. Repeat this with as many jars as you can fit into the pot without any touching. They should be covered by at least an inch of boiling water on the top, too. If the processing time is 30+ minutes, then make sure that they’re covered by 2 inches!

Once all the jars are placed, cover the canning pot with a lid and bring it back to a rolling boil (you can lift the lid occasionally to check, as it may take up to 10 minutes). Then start the timer (only AFTER it’s back at a rolling boil!) for the correct processing time (refer to the recipe notes for the exact times). The processing time will vary based on what you’re preserving, the altitude, and whether you’re hot-packing or raw-packing (read FAQs).

Check on the water level occasionally in case it needs topping up.

Step 4: Remove the jars from the pot

After the processing time, switch off the heat and remove the lid of the pot. Let the jars sit inside the water for a further 5 minutes. This will allow the pressure to stabilize and prevent siphoning.

Then, using the canning tongs, carefully lift the jars out of the pot. Lift them vertically, please! It doesn’t matter if there is water sitting on top of the lid, it will dry. Place them on a heat-proof flat surface with space in-between (I used a wooden board, you could use a kitchen towel-covered worktop) and allow them to dry fully.

If the bands around the lids look loose at this point. That’s normal- don’t touch them or re-tighten them. During the processing, oxygen will escape the jar, which will then cause a seal when fully cooled; at that point, the ring has done its job and can be removed.

Step 5: Leave to cool and store

Leave the jars undisturbed for at least 24 hours before handling. At that point, you can check that the jars are properly sealed. With button lids, you may hear the button “pop” once during the cooling time; this is it sealing – and will no longer be pressable. For lids that you tightened with a ring, you can now remove the rings and check the cap is tightly sealed by pressing on the center of it – if it feels secure, with no give/wobble, they’re properly sealed.

If any jars aren’t properly sealed, these can either be reprocessed within 24 hours with new lids (and jars if necessary) or transferred to the fridge to use within several days (or freezer for longer).

Finally, rinse the jar and dry it. Then label the jar with the item and date, then store the jars in a cool, dark location like a kitchen cupboard or pantry (these are now shelf-stable, so don’t require refrigeration) for up to a year!

Don’t store the jars above 95 ºF/35 ºC, near any furnace/range/hot pipes, or in any damp environment. If you do, it may break the seal and cause food spoilage.

The Hot Water Bath Canning Steps Summarized

I know, I know, this is a LOT of information. So here is a quick summary of the process, if needed.

• Clean your workspace and sterilize the canning equipment in hot soapy water.
• Ten minutes before required (at least), boil the jars in your prepared canning pot (with the rack at the bottom) to kill off remaining germs and keep them warm (a must to avoid any temperature shock).
• Fill each jar with your food item either using a NON-REACTIVE ladle or ladle and canning funnel (for cleaner transferring). Make sure to leave the correct amount of headspace in each jar!
• Then, carefully wipe the lip of the jar with a clean towel/napkin and close the lid band until finger-tight (no further!)
• Carefully transfer the jars (upright so no food touches the lid!) to the canner. Make sure the jars are covered with 1-inch of water (2-inches for processing times above 30 minutes).
• Then cover with a lid, and bring back to a rolling boil over high heat. Then, start your timer and process for the time provided in the recipe. Check on the water level occasionally, so it’s always high enough (keep a boiled kettle of water on standby!)
• Once processed, remove from heat, and allow jars to sit in water for a further 5 minutes. Then carefully remove (upright again) and transfer to a heat-proof wooden board or clean kitchen-towel-lined work surface.
• Leave the jars undisturbed for between 12-24 hours until fully dry and sealed. DON’T touch them before then as it can interrupt the sealing process and/or cause a “false seal.”
• Finally, check the jars are properly sealed, then rinse, label, and store them for up to a year or fresh and delicious food!

FAQs

Can I reuse canning jars?

Yes, you can use canning jars endlessly as long as they are chip/crack-free. However, that’s not always the case for the lids. When using canning lids that are a flat disk (tin-plated), these are single-use only (but can be upcycled for various crafts). However, the canning rings are usable until they rust/damage.

What canning jar is best to use?

There are two main types of jars: regular mouthed and wide mouth. Wide mouth jars are generally easier to fill and remove larger foods from but also cost more. For that reason, I use regular-mouth jars for sauces and other liquids. Meanwhile, wide-mouth jars and kept for pickles, fruits, and other larger items.

Do I need to pre-sterilize the jars?

Actually, no – but only if you live 1001+ feet above sea level when the processing time is longer.

How do I adjust the canning process time by altitude?

While the processing time is variable based on the recipe and size of the jar, there is a general rule of thumb for altitude adjustment:

1001-3000 feet = Increase by 5 minutes
3001-6000 feet = Increase by 10 minutes
6001-8000 feet = Increase by 15 minutes
8001-10,000 feet = Increase by 20 minutes

What is hot-packing vs. raw-packing?

Raw-packing fills the jars with freshly prepared, unheated food (while the jar is hot), then topping up with hot water, juice, or syrup. In comparison, hot-packing fills jars with food that’s been boiled and simmered for several minutes before being added to the jar.

Raw-packing is most often used with pressure canning, and the excess air in the jar (because of the raw ingredients) can make the contents discolor within several months. Hot-packing is the most-used method for hot water bath canning and yields better colored and flavored foods.

Note that, no matter which method is used, the canning liquid used with the foods will need to be boiling before being added to the jar!

How do you open sealed jars?

When using canning jars that don’t twist, you may be wondering how you access the food when it comes time. It’s simple; use a spoon or blunt knife to insert between the lid’s seam and the jar thread closest to the cap (the bits protruding that you use to twist a lid onto). Once in place, simply twist the spoon or knife slightly, and the lid should pop right up.

If that doesn’t work, you can use a nail or screw and hammer to make a small hole in the center of the lid (as they’re single-use anyway) and will break the vacuum seal.

How do you know if canned food is spoiled?

The easiest way to do this is by checking the seal of the lid (when using the flat screw band type lids (without the band).

Next, you can inspect the food, ensuring there are no rising air bubbles in the food or unnatural color. Then, when opening the jar, look for any mold growth on top of the food (or under the lid). Also, sniff to ensure it doesn’t smell “off.”

More How-To Guides

• Make chocolate from cocoa beans (bean to bar chocolate)
• Temper chocolate
• Pasteurize eggs (3 ways)
• Make unrefined cane sugar and jaggery
• How to make tempeh
• Flaky salt (plain and infused)
• Clean and care for a wooden cutting board
• How to Make Red Chili Paste (+ Water Bath Can It)
• Simple Fig Jam Recipe (Fig Preserves – No Pectin)

Also, you might like my list of the best kitchen tools I have – I have a lot of recommendations there.

If you try this method for water bath canning, I’d love to hear your thoughts/questions below. Also, I’d appreciate a recipe card rating below, and feel free to tag me in your canning experiments on Instagram @Alphafoodie!

A Step-by-Step Guide to Water Bath Canning for Beginners

An easy guide to water bath canning for beginners – this at-home canning technique is perfect for preserving jams/jellies/preserves, fruits, pickles, and tomato products for up to a year of locked-in freshness and flavor!

5 from 4 votes

Course: DIYs

Shelf life: 1 Year

Prep Time: 40 minutes

Water Bath Canning (varies): 15 minutes

Total Time: 55 minutes

Author: Samira

Suggested Equipment

• ▢

  NEEDED

• ▢

  Glass jars

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  Canning tongs

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  Canning pot

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  Microfiber cleaning cloth

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  EXTRAS

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  pH strips

• ▢

  Canning funnel

• ▢

  Bubble Remover

• ▢

  Magnetic lid wand

Instructions

Step 1: How to sterilize canning jars and countertops?

• To clean the working area, wipe the countertop and stovetop with soapy water.At the end of the canning process, the jars must stay on a clean surface and be left undisturbed for 24 hours. So, keep this in mind if you plan on using kitchen counter space as it may impact your cooking ability for the following day.

• Sterilize the tools (jars, lids, tongs, pot, inner rack, funnel, etc.). To do so, start by washing the items in hot, soapy water. Then, rinse well and place the jars into boiling water – this will help to keep them warm until they're filled (so they aren't "shocked" when transferred to the canning pot and crack) – or for at least 10 minutes.

• The lids and extra tools don't need to be boiled, just place them in a container and pour over some of the boiling water for the pot, then transfer them with clean tongs to a clean towel to thoroughly dry.

• When they're ready to fill, you'll need to use a clean kitchen towel to dry the inside of the jar THOROUGHLY before adding the food.

Step 2: Fill and close the jar

• Once the jars are ready, you can fill them with your food of choice, leaving the correct amount of headspace. To avoid messy spills, use a funnel.Once filled, make sure to eliminate any air bubbles, as these will impact the shelf life and can increase the headspace, and cause a "false seal." Either use a bubble tool or a sterilized chopstick/plastic knife to press into the corners and anywhere bubbles may be. You can also lightly tap the jar against your countertop to bring any air bubbles to the top of the jar.Depending on the product, you can add extra protection for the home-canned food with a thin layer of olive oil. Then wipe the lip of the jar with a clean towel/napkin, and close the jar until finger-tight (securely screwed until the point of resistance, but not too tight that air can't escape during the processing).

Step 3: Process the jars

• Meanwhile, as you were filling the jars, place the rack inside your canning pot and fill the pan halfway, bringing the water to a boil (remember that adding the cans will cause the water to rise, so you don't want to overfill it at this point).To test exactly how much water you need for your pot before using it for the first time, you can fill your jars with water, place them in your pot and then add enough water to cover the jars by at least an inch. Then remove the jars and see how much water is in the pot. That's how much you'll need to add every time! It's a good idea to boil the kettle simultaneously, though in case you need a little extra water during the processing.

• Once the water is boiling, use the canning tongs to carefully place the jars inside the boiling canning pot, ensuring they remain vertical the entire time. Repeat this with as many jars as you can fit into the pot without any touching. They should be covered by at least an inch of boiling water on the top, too. If the processing time is 30+ minutes, then make sure that they're covered by 2 inches!

• Once all the jars are placed, cover the canning pot with a lid and bring it back to a rolling boil (you can lift the lid occasionally to check, as it may take up to 10 minutes). Then start the timer (only AFTER it's back at a rolling boil!) for the correct processing time (refer to the recipe notes for the exact times). The processing time will vary based on what you're preserving, the altitude, and whether you're hot-packing or raw-packing (check the FAQs for more info).Check on the water level occasionally in case it needs topping up.

Step 4: Remove the jars from the pot

• After the processing time, switch off the heat and remove the lid of the pot. Let the jars sit inside the water for a further 5 minutes – this will allow the pressure to stabilize and prevent siphoning.

• Using the canning tongs, carefully lift the jars out of the pot. Lift them vertically, please! It doesn't matter if there is water sitting on top of the lid, it will dry. Place them on a heat-proof flat surface with space in-between (I used a wooden board, you could use a kitchen towel-covered worktop) and allow them to dry fully.

• If the bands around the lids look loose at this point, that's normal – don't touch them or re-tighten them. During the processing, oxygen will escape the jar, which will then cause a seal when fully cooled; at that point, the ring has done its' job and can be removed.

Step 5: Leave to cool and store

• Leave the jars undisturbed for at least 24 hours before handling. At that point, you can check that the jars are properly sealed. With button lids, you may hear the button "pop" once during the cooling time; this is it sealing – and will no longer be pressable. For lids that you tightened with a ring, you can now remove the rings and check the cap is tightly sealed by pressing on the center of it – if it feels secure, with no give/wobble, they're properly sealed.If any jars aren't properly sealed, these can either be reprocessed within 24 hours with new lids (and jars if necessary) or transferred to the fridge to use within several days (or freezer for longer).

• Finally, rinse the jar and dry it. Then label the jar with the item and date, then store the jars in a cool, dark location like a kitchen cupboard or pantry (these are now shelf-stable, so don't require refrigeration) for up to a year!Don't store the jars above 95ºF/35ºC, near any furnace/range/hot pipes, or in any damp environment – or this may break the seal and cause food spoilage.

  How long do you leave jars in hot water bath?

  Start timer when water starts boiling. Every recipe is different, but you'll usually boil the filled jars about 10 minutes. Once finished, shut off heat and remove canner lid allowing steam to escape away from you. Let jars rest in canner for 5 to 10 minutes.

  Do you cover jars in a hot water bath?

  Once all the jars have lids and rings, lower them into your canning pot. Make sure the jars are fully submerged and are covered with about an inch of water (you need that much to ensure that they won't become exposed during boiling).

  Can I seal canning jars without boiling?

  While the old guidelines recommended dropping the lids in hot, simmering water before pulling them out and immediately sealing jars, Jarden now says it's not necessary to heat the lids in order to achieve a good seal.