Category Archives: Freezing

Do Those Sprouts Really Come from Brussels?

Probably not. Brussels sprouts may be grown in your very own home garden and still qualify as Brussels sprouts, though they are very popular and may have originated in Brussels, Belgium. Whether you actually have Brussels sprouts growing in your garden right now might depend on where you live and what the weather has been like this year, but as long as you have access to a grocery store with a healthy selection of seasonal vegetables, you can probably find some sprouts nearby. The best time to buy Brussels sprouts is between September and March. Brussels sprouts are notable not just for their unusual appearance, but also for their hardiness in cold weather. They are even said to be best when harvested after a couple of good freezes.

So it may not be surprising then that freezing Brussels Sprouts is a highly recommend method of preserving them. They will maintain best quality for up to 12 months in a 0°F freezer. To prepare them for freezing, select green, firm, and compact heads, removing any insects and course outer leaves. Wash well, then sort into small, medium, and large sizes if size variance is notable. Water blanch small heads for 3 minutes, medium heads for 4 minutes and large heads for 5 minutes. Cool them quickly in cold water or an ice bath, drain thoroughly, and package with no headspace. Then simply seal the containers and place in the freezer. To have properly proportioned serving sizes straight from the freezer and ready to be cooked, note that 5-6 sprouts equal one serving and/or one pound equals four servings.

If you’re feeling adventurous, then you might like also to try canning Pickled Brussels Sprouts. You may not have tried these before — the brine imparts flavor that is typical of many vegetable pickles while the texture is certainly more difficult to come by. Brussels Sprout pickles are made by boiling the clean sprouts in salt water (4 tsp canning salt per gallon), then cooling them while you prepare the brine that will be poured over the sprouts once they are in jars; the brine is a mixture of vinegar, sugar, onion, diced red pepper, mustard seed, celery seed, turmeric, and hot red pepper flakes. For the complete recipe, detailed instructions, and canning process time, see the recommendation in the link above. The same recipe and canning process is used for cauliflower too, so if you have some cauliflower flowerets around you could make both kinds (note that Brussels sprouts need to boil in the salt water for one minute longer than cauliflower).

Some of the information in this entry comes from Buying, Using, and Storing Vegetables from the University of Georgia.

Going Nutty Over Advice for Preserving Nutmeats?

This time of year, you might be eager to find the best way to make your bounty of pecans, almonds, chestnuts, walnuts or peanuts last through the holiday season and beyond. While canning is a go-to for preserving, let’s not forget that some foods don’t fare so well as a canned product. USDA has never had a home canning recommendation for canning a pack of only nut meats, and the NCHFP website only has a recommendation for canning green peanuts from past work at the University of Georgia.

A previously (and no longer) recommended canning process for “canning” dry nutmeats found in So Easy to Preserve from the University of Georgia is no longer included in the new edition of the book. It was actually just a way to create a vacuum-sealed jar and there was no documentation for any microbial sterilization that might have been taking place. Questions about the risk (even if a low risk) of some bacterial growth if condensation of moisture occurred inside the jars from canning in boiling water led to re-consideration of this advice for sealing jars. Compared to when this was first published years ago, now there are other ways to vacuum pack dry, shelled nut meats at home without heating in boiling water.

Nuts tend to store very well by proper drying and storing in air-tight containers in a cool location. Refrigerated (at 32-45°F) nuts will maintain quality for one year and frozen (at 0°F) nuts will maintain quality for 1, 2, or even 3 years depending on the type of nut. See this publication from the University of California for more specific information about harvesting and storing different types of nuts.

While we know of no tested recommendations for canning pecan pie filling, another common request, you can easily make your pecan pies as usual, cool rapidly, and then freeze briefly before packaging for long term freezer storage (pies will be easier to wrap after freezing). Stored at 0°F, frozen pecan pies are expected to last 3-4 months.

Conserves are a delicious way to use up smaller quantities of nuts. By definition, conserves are jam-like products that contain nuts, raisins, and/or coconut. These conserve recipes allow you to choose your preferred nut type: Apple Conserve, Apricot-Orange Conserve, Cranberry Conserve, Damson Plum- Orange Conserve, Grape Conserve, and Plum Conserve.

Are you wondering why it’s ok to can nuts in conserves but not by themselves? The recommendation we withdrew was just one procedure for canning a jar of all nutmeats in a dry pack. There is nothing wrong with canning foods with nuts in them, if tested that way. Other recommendations (like conserves) were developed with a called for amount of nuts along with other ingredients which influence the characteristics of the final product. Let’s consider Apple Conserve, for example: Apples are an acid food and the lemon juice is a strong acid; if other ingredient proportions are kept as expected, the final product should remain acid enough for boiling water canning. Furthermore, in this conserve, the pectin and sugar combine with this acid and fruit to make a gel, which reduces the water activity of the final product. These characteristics make a difference in what the process recommendation should be, and were taken into consideration for that recipe when a canning process was determined.

Preserving Potatoes

potatoes

Not known for their fragility, potatoes are a robust, starchy tuber in the nightshade family (along with fellow Solanaceae family members tomatoes, eggplants, and peppers). Potatoes pack a nutritional punch, weighing in with substantial amounts of potassium, fiber, protein, vitamin C, Vitamin B-6, Magnesium, and a lesser but still notable amount of Iron.

It’s easy enough to store fresh white potatoes for up to 2 months in a cupboard kept at 50-70°F (sweet potatoes last only 2-3 weeks). But what if you want them to last even longer?

Interestingly, storing white potatoes in a refrigerator is likely to diminish their quality and they are expected to last only 1-2 weeks there. Alternatively, you could cook and mash them, stuff them, or scallop them for freezer storage, but again, they will retain best quality only for a few weeks in the freezer.

Drying is an option for making potatoes last longer. Wash, peel, then cut potatoes into 1/4-inch thick shoestring strips, or cut into 1/8-inch thick slices. Steam blanch the prepared pieces for 6-8 minutes or water blanch them for 5-6 minutes. Plan for a drying time of 8-12 hours in a dehydrator and up to twice as long in an oven, depending on circulation. If you dry sweet potatoes and want to rehydrate them for a recipe, combine each cup of dried pieces with 1-1/2 cups water and let them soak for 30 minutes.

As for canning potatoes, our recommendation is to peel potatoes before canning. That style of preparation is how the research was carried out to determine the recommended processing, and in order to know that the peeling does or does not make a difference, research would need to be done with unpeeled potatoes. Different assumptions might be needed in assessing just how many spores of C. botulinum or other bacteria might be present at the start of the process and what amount of heat might be needed to meet standards for the risk of possible survivors. We do not know of research of canning potatoes with peels left on, so we recommend the preparation steps provided with the process recommendation, especially because there is a possibility that the deviation could result in a less safe situation. Also due to safety concerns, it is important to use potatoes that are only 1 to 2 inches in diameter if you are canning them whole.  These are sometimes described as “new” potatoes; the idea is to use less mature, smaller potatoes which tend to be less starchy than older, “grown-up” potatoes.

White potatoes for canning should be the “waxy” or “boiling” kind.  Different types of potatoes have different amounts and types of starches and they react to heating differently.  You want a potato that keeps its shape and texture well after a lot of heating, and not one that falls apart, becomes “fluffy” after cooking, and is better for mashing. Most red-skin potatoes are of lower starch than baking potatoes  and work well for canning. Many white round potatoes with thin skins fall into this category with red-skin potatoes too. Russets are not good for canning but are  good for baking (they have a high starch content).  Yukon Gold may not be the best potatoes for canning.  While they seem good for boiling, they do tend to fall apart when overcooked.  From what we have read, there is a wide variety in the types and amounts of starches in blue potatoes, so not all blues are the same, just like not all white potatoes are the same in these characteristics.

Sweet potatoes can be slightly larger, but medium-sized potatoes should be cut to fit in the jar in uniform-sized pieces. Note that the sweet potato pressure canning process time is significantly longer than for white potatoes.

Sweet potatoes can have a sugar syrup for canning, if you like that style. But otherwise, all potatoes — white or sweet — should have fresh, boiling water prepared to pour over the preheated potatoes.  Do not use the cooking liquid.  That cooking water contains a lot of starch that comes out of the potatoes and the process time was determined using fresh boiling water to cover.  The added starch can create  a safety problem by slowing down heating of the potatoes in the canner, and it also creates a very unappealing pack with possible masses of gelled or congealed starches around the potatoes.  If you have spoilage, this makes it very hard to see the signs of some spoilage.

Corn-ucopia

Have you got a cornucopia of corn starting to come in? Or maybe you just really enjoy crunching on fresh kernels from a grocery store? Well, if you want that great flavor to last, then try one (or all!) of these methods of preserving corn…

Instructions for freezing corn-on-the-cob, whole kernel corn, and cream style corn are in a previous post – Corn: On or Off the Cob.

If you’re wondering what to do with all those frozen corn kernels, or if you have 16 to 20 medium-sized ears, and you’re feeling a little zesty, then try making Pickled Corn Relish and processing it in a boiling water canner.

Corn in HuskThe rest of these canning recommendations are not pickled products, and so a pressure canner is required since corn itself is a low-acid food. Corn can be canned as Whole Kernel Corn or Cream-Style Corn. Sweet corn kernels may also go into a medley of Mixed Vegetables or Soup (note that the pressure canning process time varies – following the recommended process time is important to the safety of the final products…the soup has a lot more water to help distribute heat more quickly, and also less solids to have to penetrate through).

If your corn browns during canning, it usually means that the temperature required for canning is too high for the sugar levels in your corn variety.  This carmelization has become more of a problem as newer varieties of corn get sweeter and sweeter. You cannot safely reduce the heat or processing time needed for canning corn; you can freeze that corn or find a locally grown variety that is recommended for canning. Though not an immediate safety concern, you might want to consider refrigerating these jars and/or consuming them more quickly since they may not maintain the best quality for long.

Corn can also be dried, although consider your use of the kernels to decide if the texture is what you are seeking. Ears of popcorn can simply be left to air-dry on the stalks or at 130°F after harvest. For other varieties of corn, husk, trim, and steam blanch for 2 to 2-1/2 minutes or water blanch for 1-1/2 minutes. A test to check if it’s blanched enough is to cut into a kernel — if milk does not exude when the kernel is cut then it is adequately blanched. After blanching, cut kernels from the cob. Use a dehydrator try liner (or a cookie sheet if drying in the oven) so that the small pieces don’t fall through. Dry in an electric dehydrator at 140°F for 6 to 10 hours, longer in an oven. To rehydrate the kernels, soak each cup of corn in 2-1/4 cups water for 30 minutes.

Lastly, let’s not forget candy corn this time of year…it typically stores well on the counter in an airtight container (perhaps out of sight from children!).