Newsflash

Newsflash

Home Canning Safety: Why the Type of Bottled Lemon Juice Matters

You may have noticed more brands of bottled lemon or lime juice labeled "not from concentrate" appearing on grocery store shelves. These products may be great for cooking and everyday use, but they are not the correct choice for home canning. We know many of you have questions about these newer products and about sulfite-free options, so here’s what we can and can’t recommend.

For canning, always choose bottled lemon or lime juice made from concentrate.

Why?

Acidity is one of the key factors that determines a safe canning process and helps reduce the risk of botulism, so getting it right matters.

Bottled lemon or lime juice from concentrate is required to meet a guaranteed acidity level, so you know exactly how acidic it is every time. Juice that is not from concentrate doesn't come with that same guarantee. It may be just as acidic, but there's no way to know for sure, and it can vary more from bottle to bottle depending on factors like the fruit's maturity and variety.

Since food safety in canning depends on getting the acid level right, it's best to stick with a product that has a guaranteed acidity: bottled lemon or lime juice from concentrate.

Curious why we don't recommend testing acidity at home with a pH meter instead? Read our Newsflash on home pH testing.

What about juice labeled “5% acidity”?

Some not-from-concentrate brands print an acidity percentage on the label, and others don’t. The federal standard for lemon juice sets a minimum acidity only for juice made from concentrate. For not-from-concentrate juice, an acidity claim is voluntary. It has to be truthful, but there’s no required testing schedule or FDA verification behind it, and natural juice can still vary from batch to batch. Our tested canning recipes were developed using bottled juice from concentrate. Because of that, we can’t say a not-from-concentrate juice is equivalent, even when the label lists an acidity.

What if I’m sensitive to sulfites?

Most bottled lemon juice from concentrate contains sulfites as a preservative. If you need to avoid them:

• Tomatoes: Use citric acid instead of lemon juice. It’s sulfite-free. Vinegar can also be used, but it may change the flavor.

• Other recipes: Use citric acid or vinegar only when the tested recipe lists them as an option. If lemon juice is part of the tested recipe, as it is in some salsas, don’t swap in a different acid.

• Jams and jellies: Select a recipe that doesn't contain lemon juice or consider making freezer jam. In freezer jam, lemon juice helps the pectin set, but isn’t needed for safety, so fresh-squeezed or not-from-concentrate juice is fine to use. Note: Commercially produced pectin can contain a low level of sulfites. Please check with the pectin manufacturer to ask about sulfite content. For a product free of addd sulfites, choose a recipe without added pectin and without lemon juice, such as our berry jam without pectin. 

• There is at least one brand of organic bottled lemon juice available that is made from concentrate. Always double-check the label to make sure the juice is both from concentrate and sulfite-free.

Why can’t you just recommend a substitute?

Swapping one acid for another isn’t a simple one-to-one change. Acids differ in strength and in how they behave in a recipe, so any new recommendation has to be tested in the lab with the actual recipe. That kind of research takes months to years. Until then, the safest choice is to follow your tested recipe as written or choose a tested recipe that uses the acid you prefer.

The safe choice

• Check the label: look for "from concentrate" or "reconstituted."

• Use bottled lemon or lime juice from concentrate any time a recipe calls for it to acidify food (like tomatoes or salsa) or to help jams and jellies set (Freezer jams are the exception; see above).

• Never substitute fresh-squeezed juice or juice "not from concentrate" in a canning recipe.

• Not sure how much to use? Always follow the amount listed in your tested recipe. For tomatoes, see our acidification directions.

Newsflash

Using Frozen Tomatoes in Home Canning

Key instructions for using frozen tomatoes in home canning:

Freezing ruptures the cellular walls of tomatoes, causing them to collapse and lose structural integrity upon thawing. This process significantly alters the texture, yielding a softer, mushier consistency that makes whole or halved tomatoes and salsas unappealing. To achieve optimal quality, incorporate thawed tomatoes, and their juices into a validated tomato or spaghetti sauce recipe, where structural changes will not compromise the final result.

• Keep All Released Liquid: Tomatoes release a significant amount of juice as they thaw. Include 100% of this liquid in your preparation; it is accounted for in research-tested recipes and essential for correct acidity and volume.

• Use Hot Pack, Not Raw Pack: Thaw tomatoes in the refrigerator, then heat all solids and liquids before jar packing. Do not raw pack thawed tomatoes since this leads to potentially overpacking and under processing, given they lose water during the thawing process.

• Watch Out for Overpacking: Because thawed tomatoes lose structural integrity and collapse, it is easy to pack too many into a single jar. Overpacking prevents proper heat penetration, which can leave harmful bacteria alive.

• Mandatory Acidity: Always follow a research-tested recipe and add the required amount of bottled lemon juice from concentrate, citric acid, or 5% acetic acid vinegar directly to each jar to ensure safe pH levels. See our tomato acidification instructions for details.

Newsflash

Atmospheric Steam Canning Statement

The National Center for Home Food Preservation considers atmospheric steam canning a safe method for processing high-acid foods, like fruits, jams, pickles, and tomatoes, when tested recipes and recommended processing guidelines are followed. Research shows that atmospheric steam canning provides enough heat to destroy microorganisms that could make you sick. However, some very heat-resistant microorganisms that cause food to spoil may survive the process. This means that, when atmospheric steam canning guidelines are properly followed, these surviving microorganisms are considered a potential food quality concern, not a food safety concern. In some cases, they could eventually cause the food to spoil, but they are not expected to cause foodborne illness.

 Approved atmospheric steam canning guidelines: 

●     https://www.ncrfsma.org/files/page/files/fn2065_steam_can_it_right_fillable.pdf 

●     Follow the manufacturer's instructions for the specific steam canner you purchased, including assembly instructions.

 Also follow these two extra steps every time you use atmospheric steam canning:

●      Before you start timing: Use a thermometer to check the temperature of the steam coming out of the vent hole on the side of the canner. Wait until there is a steady, strong column of steam, then insert the thermometer stem through the vent hole, making sure it does not touch any jars. Confirm the temperature reads 210-212°F (the exact number depends on your elevation) before starting your processing timer.

●      After the processing time is complete: Turn off the heat and leave the lid on. Let the jars sit undisturbed in the canner for 5 minutes before removing them.

September 2026

Newsflash

New Kombucha Recipe!

Interested in brewing your own kombucha at home?

Making kombucha can be a fun and rewarding way to enjoy a refreshing beverage while exploring the science of fermentation. But before you get brewing, it’s important to understand proper preparation and fermentation techniques to help ensure a safe, delicious final product.

Good news! The National Center for Home Food Preservation has published a research-based recipe for making kombucha tea at home. This recipe provides evidence-based guidance to help you brew kombucha while following recommended food safety practices.

Ready to brew? Check out the new kombucha recipe and give it a try!

Newsflash

Why Experts Say “No” to pH Meters in Home Canning

pH is a scale from 0 – 14 that measures how acidic or basic a substance is. Using a pH meter at home may sound like a good idea, but it can actually make your food less safe. Here’s why:

1. pH Meters Aren’t Reliable Enough for Home Use

· Home (consumer-grade) pH meters can give readings that are off by a large margin.

· Even a small error can make the difference between a safe and unsafe product.

· This is especially risky for acidified foods like salsa or pickled vegetables, where pH must be precisely below 4.6 to prevent botulism.

· It is not just the liquid portion of the product that must be measured. Measuring pH of solids and liquids must be completed with the correct procedures (i.e. drain solids, record weights, blends solids, dilute with distilled water if needed, etc.)

· Home pH meters cost between $10 and $150 and are less accurate while professional ones range from $1000 to over $5000.

2. Professional Meters Need Regular Calibration

· True food-testing pH meters must be calibrated daily with fresh, lab-grade buffer solutions.

· Most home users don’t have access to the correct calibration materials or the training to use them properly.

· An uncalibrated meter = inaccurate readings, which can lead to false confidence in unsafe products.

3. Temperature Affects Accuracy

· pH readings change with temperature.

· Measuring hot or cold samples can give false results unless the meter automatically compensates for temperature — most home meters do not.

4. Cleaning and Maintenance Are Critical

· The pH probe must be cleaned, stored, and maintained correctly.

· If not, the sensor can become contaminated or damaged, leading to wrong readings or even cross-contamination between samples.

5. pH Isn’t the Main Safety Factor for Low-Acid Foods

· For low-acid foods, the time and temperature combination during processing, not pH, determines safety.

· Using a pressure canner, tested recipes, and correct processing times are what protect against Clostridium botulinum (botulism).

· pH is one of the factors used to set the targets for the amount of heat required during water bath processing, pH itself is not the target. Recipe validation requires a heat penetration study in order to determine the processing time, not just a measurement of pH.

· thickness of the mixture and size of the pieces also affects safety.

The Safe Choice

· Always use research-tested recipes from trusted sources like the National Center for Home Food Preservation (NCHFP) or other Extension services.

· Follow directions for processing time, pressure, and elevation adjustments.

· If a recipe depends on acidity, rely on measured ingredients (like vinegar or lemon juice), not home pH meters.

· A pH of 5.0 in vinegar does NOT mean 5% vinegar to be used in canning.

Newsflash

Webinar Recordings Now Available

If you missed one of our webinars, you can now view the recordings in the Resources section. 

Botulism: Home Canning Enemy #1 with Dr. Scott Whiteside of Clemson University

Expanding Your Home Food Preservation Toolkit with Freeze-drying with Andy Hirneisen of Penn State University

Newsflash

February 13 Webinar - Expanding Your Home Food Preservation Toolkit with Freeze-Drying

NCHP is excited to host a webinar on February 13 titled Expanding Your Home Food Preservation Toolkit with Freeze-Drying.

This webinar will guide you through freeze-drying as a method of home food preservation.

Date: February 13, 2026
Time: 12:00–1:00 p.m. ET
Speaker: Andy Hirneisen, M.A., Distinguished Extension Educator and Team Leader, Retail and Consumer Food Safety, Penn State University

Register in advance for this webinar:

https://zoom.us/webinar/register/WN_qaDu2tR1Q-eEfGT4Wo9Z1w

After registering, you will receive a confirmation email containing information about joining the webinar.

A flyer is available for you to share

Newsflash

January 30 Webinar - Botulism: Home Canning Enemy #1

NCHP is excited to host a webinar on January 30 titled Botulism: Home Canning Enemy #1.

This webinar will focus on botulism risks associated with home canning and reinforce research-based practices critical for preventing Clostridium botulinum in low-acid foods. 

Date: January 30
Time: 12:00–1:00 p.m. ET
Speaker: Dr. Scott Whiteside, Food Systems and Safety Program Team, Food, Nutrition & Packaging Sciences Department, Clemson University

Zoom information:
Zoom ID: 929 8945 3125
Passcode: 641913

A flyer is available for you to share. 

 Calendar Reminder (link to .ics file download)

Newsflash

SAVE THE DATE! Two upcoming food safety webinars in the new year!

We're excited to host two upcoming food safety webinars in the new year! 

January 30 | 12-1 PM EST

Dr. Scott Whiteside of Clemson University will discuss botulism and what you need to know to keep your pantry safe.

February 13 | 12-1 PM EST

Andy Hirneisen, MA from Penn State Extension will guide you through freeze-drying.

A flyer with this save-the-date information is available for you to share.

Mark your calendars and stay tuned for more information! Sign up information will be coming in early 2026.

Newsflash

Low-acid additions can make your jams and jellies unsafe—Here’s why:

Low-acid additions can make your jams and jellies unsafe—Here’s why:

When it comes to home canning, safety is more important than flavor. Adding low-acid ingredients—such as jalapeños (and even pickled jalapenos) or other low acid ingredients—to jams or jellies that haven’t been tested with them can make the final pH unpredictable. These types of changes could raise the pH to a level where harmful bacteria can grow. While sugar in large amounts can help slow microbial growth, safe preservation depends on the exact ratio of fruit to sugar to low acid ingredients and sometimes added acid. Without a tested recipe that accounts for the peppers, there’s no guarantee the product will be safe for shelf storage. 

When canning, it is essential to use only recipes that have been scientifically tested and validated for safety. Below are two pepper jelly/jam recipes that meet these standards.

https://nchfp.uga.edu/how/make-jam-jelly/jellies/mayhaw-pepper-jelly-pectin/

https://enewsletters.k-state.edu/youaskedit/2017/08/15/peach-jalapeno-jam/

Please note: do not substitute the type of fruit in these recipes, as safety testing has not been conducted for variations.

A safe way to add extra flavor to your jams and jellies is by incorporating a small amount (1 teaspoon or less) of herbs or other flavorings into a tested fruit recipe. For example, basil can be added to strawberry jam, or vanilla to cherry jelly, without compromising safety. For more safe substitutions, please check out this guide: https://www.ndsu.edu/agriculture/sites/default/files/2024-03/fn2102.pdf

August 2025