Sweet and smooth, perfumed with warming spices, pumpkin butter is a real autumnal treat. People naturally want to give their homemade pumpkin butter as a food gift.Yet year after year, people are disappointed to learn that they cannot can it at home, neither by water bath canning nor by pressure canning. The same holds true for unsweetened purées of pumpkin and winter squash. Pumpkin butter and purée can, however, be safely frozen.
Why Pumpkin Butter Can't Be Canned Safely
The reasons for this have to do with two of the major factors for safety in canning: Acidity and viscosity.Pumpkin and squash are low-acid foods.In order to be safe for water bath canning, food must have a pH level of 4.6 or lower, preferably 4.2 to account for variation, in order to suppress the growth of c. botulinum bacteria that can cause botulism poisoning. Since pumpkin and squash not only are low-acid but also can have highly variable acidity by the variety and by how they were grown and harvested, there is no clear amount of acidification to recommend across the board.According to theNational Center for Home Food Preservation, even when acidified with vinegar or lemon juice, "pumpkin butters produced by home canners ... have had pH values as high as 5.4. In fact, the pH values seemed to be extremely variable between batches made by the same formulation."
Low-acid foods can be pressure canned, and in fact, it is possible to pressure can pumpkin, so long as it is cubed and packed in water. Pressure canning reaches temperatures sufficient to destroy the c. botulinum bacteria. As for purées and butters, again according to the NCHFP, studies "indicated that there was too much variation in viscosity among different batches of prepared pumpkin purées to permit calculation of a single processing recommendation that would cover the potential variation among products." In short, different squashes have different densities, and if a purée were too viscous, there may not be sufficient heat penetration during the canning process to kill off any pathogens in the center of the jar—even in a pressure canner.
What About Pumpkin Butter Sold at Farmers Markets?
So why, then, do you see canned pumpkin butter for sale from small-batch food producers at places like farms and farmers' markets?How do they get away with it?In short, it is technically possible to formulate a recipe that is both sufficiently acidified and has a suitable viscosity; it is not, however, possible to create one that works for all squashes in all kitchens all the time.
Wendy Read of Sunchowder's Emporia, an independent preserves maker that markets a pumpkin butter, explained how. It turns out that the FDA has a code of regulations in place specifically for food vendors who are acidifying low-acid foods, which includespumpkinbutter but also things like pickles.
In order to get permission to sell acidified foods, a vendor must submit what's called a "scheduled process," basically outlining not only the recipe but also detailed information on how the foods will be prepared, packed, and processed. This goes to an FDA-approved food safety and stability testing facility for review. Once approved, they send a Process Authority Letter, which enables the vendor to begin producing the food. However, that vendor must then carefully document a litany of things each time they produce a batch—ingredients, pH, fill temperature, processing times, cooking and cleaning procedures, and type and size of the container—to confirm that they are adhering to the approved process. If they vary from the process in any way, they must get an entirely new Process Authority Letter to continue. So you see, this is certainly more than the average home canner can take on for a simple food gift.
Lest you think this is too absurdly onerous a procedure, keep in mind that in August 2014, a California company's jarred sauce was recalled after two people in Ohio were hospitalized with botulism. While it's true that there are only about 20 or so cases of food-borne botulism recorded in the U.S. each year, and only 11 people died of it between 1990-2000, with safe practice it can be prevented altogether.
FAQs
Home canning is not recommended for pumpkin butter or any mashed or pureed pumpkin or winter squash.
Can pumpkin butter be safely canned? ›
Home canning is not recommended for pumpkin butter or any mashed or pureed pumpkin or winter squash.
Why is it not safe to can pumpkin puree? ›
There are no research-tested pressure canning recipes for puréed pumpkin that prove the amount of heat penetration into the center of the product is adequate to eliminate the risk of Clostridium botulinum, which can cause botulism toxin and be deadly.
Is it safe to pressure can butter? ›
Butter, milk and cream (like meat and vegetables) are low-acid products that will support the outgrowth of C. botulinum and toxin formation in a sealed jar at room temperature. Low-acid products have to be pressure-canned by tested processes to be kept in a sealed jar at room temperature.
How to pressure can pumpkin puree in a jar? ›
Process filled jars in a pressure canner at 10 pounds pressure for 55 minutes for pints and 90 minutes for quarts, adjusting for altitude. Remove jars and cool. Check lids for seal after 24 hours. Lid should not flex up and down when center is pressed.
Can you can pumpkin without a pressure canner? ›
It must be pressure canned to prevent botulism. It is not recommended to can pumpkin puree as it is too dense to heat thoroughly and kill all the bacteria. Pressure Canning is easy to do.
Why can you can apple butter but not pumpkin butter? ›
When cooked down into a butter, pumpkin flesh becomes quite dense, making it difficult for the heat produced in a canner to penetrate fully through the contents of the jar. This means that even in a pressure canner, the interior of the jar may not reach the 240 degrees needed to kill those pesky botulism spores.
Is 100% canned pumpkin the same as pumpkin puree? ›
Canned pumpkin (labeled as "100% pure pumpkin") is a purée of pumpkin that is sometimes mixed with other kinds of winter squash. It is unsweetened and does not contain any added spices. Canned pumpkin and pumpkin puree are the same thing, and you'll often see the terms used interchangeably in recipes and cookbooks.
How long does pumpkin butter last after opening? ›
This pumpkin butter makes an excellent hostess gift. Spread it on toast and muffins, add it to baked goods, or drizzle it over vanilla ice cream. Keep it in the refrigerator for up to three weeks.
Is canned pumpkin puree bad for you? ›
Canned pumpkin offers the same health benefits as fresh pumpkin, making it quick and easy to add pumpkin to recipes year-round. Pumpkin seeds are typically roasted and sold separately as a snack or topping.
botulinum and toxin formation in a sealed jar at room temperature.” She explained that fats can protect botulism spores and toxins from heat if they are in a product during a canning process. This is why canning milk, butter and/or the addition of milk or butter to other products to be canned is not recommended.
What vegetables Cannot be pressure canned? ›
All vegetables, except tomatoes, should be canned in a pressure canner at 10 pounds pressure (240°F). You may can tomatoes in either a water bath canner or a pressure canner, but you should always hot pack them.
Does pressure canning prevent botulism? ›
Scientifically proven pressure canning processes are designed to destroy C. botulinum spores. To Prevent Botulism from Home-Canned Low Acid Foods: In home-canning vegetables, make sure you use proper equipment, proper containers and up-to-date procedures.
Is it better to can or freeze pumpkin puree? ›
Fresh and opened canned pumpkin purée only lasts for a week stored in the fridge, but stored in the freezer it will last for months. Freezing pumpkin purée in the increments you use most makes it easier to store, thaw, and eventually use.
Do you have to blanch pumpkin before canning? ›
Blanch the pumpkin pieces.
Place the pumpkin cubes in boiling water for about two minutes. As they go through this blanching, use hot water to heat your glass cans to avoid an overwhelming temperature shift when you add the hot pumpkin pieces. A drastic change in temperature could cause the glass to crack.
Is pumpkin puree in a can? ›
First and foremost: what is pumpkin puree? Canned pumpkin and pumpkin puree are the same thing. These terms are often used interchangeably in recipes, though you may also see the term solid-pack pumpkin. All these terms mean 100% steamed and pureed pumpkin—no extras, no add-ins—not even in the canned variety.
Does pumpkin seed butter go bad? ›
The shelf life of pumpkin seed butter varies depending on whether it's opened or unopened and how it's stored. Unopened storebought pumpkin seed butter can last up to a year or more when stored in a cool, dark place. Opened storebought jars should be consumed within three to six months when refrigerated.
How long does store bought pumpkin butter last in the fridge? ›
Shelf Life: Store in a cool dark place unopened up to 2 years; Refrigerate after opening and use within 3 months.
Can butternut be canned? ›
As for all low-acid foods, a pressure canner is absolutely required to home can butternut squash (and all squashes.) If you don't have a pressure canner and still wish to preserve it, freeze it instead. See here for canning other winter squash, and pumpkin.
