Potatoes are a staple crop for many home growers. But many struggle when it comes to an understanding of how to store their potatoes over the winter months. Keeping potatoes in a traditional root cellar can be a great option. But the conditions required can be challenging to maintain. Home-canned potatoes are another preservation solution. But how long will home-canned potatoes last?
When potatoes are canned commercially, they are generally said to be safe for 3-5 years. But home-canned potatoes will typically last a year to 18 months. This is far longer than they will typically last when stored traditionally in a root cellar or cold store.
Though if the correct procedure has been followed, they may be safe to eat after this time, the quality will likely begin to degrade after a year or so.
However, it is important to understand that home-canned potatoes will only last this long if you have chosen the right potatoes to can, selected the right canning jars to keep them in, and followed the canning procedure to the letter. It is also crucial that you store canned potatoes in optimal conditions. Read on to make sure your home-canned potatoes are safe to eat and last as long as possible.
Choosing the Right Potatoes To Can
Canning is a particularly good solution for small potatoes, and for certain potato varieties that will not store very well in a root cellar or cold storage area. But the goal is to choose potatoes that will maintain their integrity in the canning solution. This means that overly starchy potatoes are not ideal. Those varieties that break down easily when cooked are not ideal for processing in this way.
- Choose firm-fleshed potatoes of the waxy or boiling kinds, rather than those good for mashing.
- Most red-skinned potatoes work well.
- White round potatoes with thin skins are also often ideal.
- New potatoes can better than starchier mature potatoes left in the ground for longer.
- Any potatoes that make a good, firm potato salad work well for home canning.
Potatoes should be peeled before use, for safety reasons. There is a higher risk that botulism and other pathogens can be introduced if you use unpeeled potatoes.
The quality of the potatoes you use will also have a bearing on the quality of the canned product and how long it will last. Don’t use any potatoes with green on them, or any with rotten or blemished areas.
Using the Right Canning Jars
Before we get onto the procedure for home-canned potatoes, it is also important to think about the vessels you use. Selecting the right canning jars is crucial to making sure your home-canned potatoes last as long as possible.
Many who are new to home canning opt for cheap canning jars, rather than the somewhat more expensive brand name options. But sadly, when it comes to canning jars as when it comes to so many other things – you often get what you pay for.
Using low-quality canning jars is counterproductive because it can lead to a lot of wastage. You may experience breakages, or jars may fail to seal. Seals on inferior lids may also be more prone to breaching or degradation during storage. It is important to purchase high-quality jars and canning equipment (from tried and tested manufacturers) to get the best results. Remember, the canned potatoes will only last as long as the jars and seals remain intact.
How To Pressure Can Potatoes Correctly
First of all, it is important to note that pressure canning is essential. It is not safe to can potatoes using water bath methods alone. Safety is paramount, and as a low-acid food, potatoes must be pressure canned to avoid any negative health consequences.
Potatoes can be canned in chunks of around 0.5 inch (1.3 cm) cubed. Alternatively, small potatoes (1-2 inches or 2.5 to 5 cm) can be left whole. To can your potatoes:
- Wash, peel, wash again and chop the potatoes and boil (approximately 2 minutes for cubes, 10 minutes for whole potatoes).
- Prepare your jars (1 US pint or 1 US quart size or around 500 ml). As a very rough rule of thumb, 2.25 lbs (1 kg) of potatoes will fill 1 US quart jar.
- Boil more water to use as canning water in your jars. It is best not to use the water used for boiling the potatoes. It is full of starch and could cause density issues for the tested processing times.
- Drain the boiled potatoes and pack them into your jars. Leave 1-inch (2.5 cm) headspace.
- For best results, add salt to the canning water. This is optional, but not only adds flavor but also helps the potatoes maintain good texture during the canning process. 1 tsp per quart jar is recommended.
- Top up the jars with the water/saltwater. Be sure to maintain the 1-inch (2.5 cm) headspace.
- Get rid of air bubbles around the edges of the jars.
- Wipe the jar rims (vinegar is ideal).
- Put the lids on.
- Pressure can at 10 pounds (weighted gauge) or 11 pounds (dial gauge) below 1000 ft. Adjust pressure accordingly based on your altitude.
- Process pint jars in the pressure canner for 35 minutes and quart jars for 40 minutes.
- Leave the jars to cool, remove the rings, and make sure they are sealed.
- Use any jars that have not sealed properly right away, and take the rest to a suitable storage area.
Storing Home Canned Potatoes
While it is crucial to choose the right potatoes and jars and to follow the correct canning procedure, it is even more important to make sure you store your home-canned potatoes in the right place. Storage is crucial if you want your potatoes to last, in good condition, for as long as possible.
Canned foods should ideally be stored at temperatures between 50 and 70F (10 and 21 degreed Celsius). It is important to keep them out of direct sunlight. And you should avoid storing them where temperatures fluctuate excessively. They should not be allowed to freeze, but nor should they be exposed to extremes of heat. Don’t place them near hot pipes, a furnace or stove, for example.
At prolonged storage temperatures above 75 F (24 degreed Celsius), nutrient loss in canned foods will accelerate, so while they may still be safe and taste fine, they will not be as good for you. Never store your canned potatoes where temperatures rise about 95 degrees F (35 degrees Celsius).
The storage location should be dry, and you should aim to keep humidity low. Dampness and high humidity can corrode metal lids and break seals, allowing food to be contaminated or spoiled. Though difficult to achieve in many areas, a humidity of below 15% is ideal.
It is best not to double stack your jars. Try to place them in a single layer on your shelves. I recommend storing the jars with the rings off. Store the rings separately.
If kept in an ideal location, you should be able to keep enjoying your harvest of potatoes from this year right through to next summer and beyond.
How Long Will Opened Home Canned Potatoes Last?
Once opened, the home-canned potatoes should be refrigerated and used within 3-4 days. If you cannot use them within this time, you can freeze them in an airtight container, and they will be the best quality for around two months.
The great thing about home-canned potatoes, however, is that it is easy to use them up as soon as you open the jar. They are a great convenience food that can be used for quick mashed potatoes or added to soups, stews, or a range of other recipes.
Canning potatoes is not right for everyone. But it can be ideal in areas where it is difficult to obtain the right conditions for storing potatoes long-term. If you don’t have a root cellar, it is a great way to make sure that you avoid waste and can enjoy this staple food throughout the whole year.
It is important not to can more than you can use in a year or two. Practice good organizational skills, and rotate the canned goods in your pantry so that you use by the oldest food first. Remember, canned potatoes may be safe and good to eat for one year to 18 months, or even longer. But the longer you store them, the more they may deteriorate in terms of texture, flavor, and nutritional value.
Safety is crucial – always follow the instructions for canning to the letter, following expert advice. And if in doubt – chuck it out. We should never take any chances when it comes to canned goods.