Best Food Preservation Techniques
Here comes summer and the year’s best fresh foods—organic vegetables, fruits, and herbs from your garden or your local market. But before you procure a single cucumber, think about autumn and winter—and the best ways to preserve summer’s delicious, healthy delights.
Why should you think about dark winter days at this height of the growing season? Because, unless you live in a perpetually warm area of the world, fresh, organic, and, healthy foods will be far more scarce in your market’s produce section later in the year.
So here’s how you can preserve and store up your own summer foods. Reap and enjoy now, and freeze—or otherwise preserve—for delicious, healthy dining come fall and winter.
Best tips for the best preserved produce
Here are my tips on best preserving practices. Note that canning won’t be one of them. It’s a wonderful method, but doing it safely is demanding work, and there are other, easier ways:
- Olive oil immersion
- Vinegar immersion
Double buy and pre-prep
Buy for now and buy additional for freezing. Don’t let preserving be an afterthought or a way to salvage leftovers. The best preserved produce is from the market straight to your preferred preserving method.
And plan ahead for textural differences between fresh and thawed. That firm, fresh, peach won’t be quite so firm when thawed. Cutting it open to remove the pit and slice might be a bit squishy—so do that now (you’ll want small pieces anyway, as you’ll see). Cucumbers? Save as spears or disks. Slice before you freeze.
Freezing fruits and vegetables
The rules of this road are:
- Think ahead
- Think small
- Blanch or cook before freezing
- Freeze flat
- Double bag
Here’s why you’ll want smaller pieces.
Fruit and vegetable cells contain water, which crystallizes into ice during freezing. The slower the freeze, the bigger the ice crystals—and the likelihood of cell walls rupturing.
Your crisp produce just got soggy.
So go with small whole fruits and vegetables—skinny green beans, slender asparagus, small plums, etc. And cut up bigger prizes, like peppers and melons, into smaller pieces, for the same reason—faster freeze.
Fast freezing also keeps fruit and veggie enzymes under control. They’re usually locked away in the cells. But if those cells rupture during slow freezing, the enzymes can turn your trophies mushy and blah looking.
Blanch or pre-cook
Blanching will turn the enzymes off, keeping your vegetables brightly colored and crisp when thawed.
It’s simple. Pop your harvest into boiling, salted water for 1–3 minutes, until bright and tender-crisp. Remove and dry them carefully in one layer, not touching each other, on a baking sheet or plate lined with paper towels. Squeeze leafy greens in a clean paper towel to remove excess moisture.
Note: Watery or delicate produce—tomatoes, summer squash, and eggplant, for example, are especially vulnerable to cell damage during freezing. Best practice here is to thoroughly cook these vegetables before freezing. That way, they’ll have already had their cell structure broken down and their water content reduced, making a soggy, drab, outcome less likely.
Freeze fast by freezing flat
Dry your blanched or cooked fruits and vegetables thoroughly as possible. Spread them in one layer on a rimmed baking sheet, not touching, and freeze away. Frozen into separate pieces, instead of in a single frozen lump, they’ll be easy to pop into zipper-lock freezer bags or vacuum-style bags for use when you need them.
Exposure to air causes freezer burn, another way to ruin your frozen goodies. Regular plastic bags and even thicker freezer bags aren’t completely air-proof.
After putting your frozen produce in a freezer bag, squeeze out as much air as possible, seal, and put that bag into a second freezer bag and seal again. Alternatively, pack your goodies in thick, vacuum-seal bags.
Freezing is the best option for leafy herbs like basil, cilantro, parsley, and tarragon. There are different ways to do it.
You can chop the herbs, pack them tightly into an ice cube tray until each receptacle is ⅔ full, then just top them with broth, water, butter, or olive oil and freeze.
When frozen, remove cubes from ice tray, double-bag them as air-tight as possible and pop into your freezer.
You can also blend the herbs into a paste with a little oil or water before freezing. Store frozen cubes in an airtight container in the freezer.
An ingenious new option (to me) is to create a frozen “herb log.”
- Gather older, thicker-stemmed herbs. This makes room for fresh, new growth.
- Discard stems and rinse and dry leaves thoroughly
- Fill a freezer bag with clean, dry leaves. Pack them tightly, as far down into the bag as you can.
- Roll up the bagged leaves from the bottom, squeezing out as much air as you can. You should have a “log” of tightly packed leaves.
- Wrap the log in a rubber band and freeze. When you need a bit of your herb, you can simply slice a disc off the log.
Drying works well for small-leaf herbs like oregano, thyme, marjoram, and sage.
After collecting stems, shake and gently rub them to remove dirt, and toss withered leaves.
Secure the stems together using string, a twist-tie, or a rubber band, and hang upside down in a warm, dry, well-ventilated place, away from sunlight.
You can loosely cover the bundle with a paper bag if you don’t have the perfect spot. Just leave space for air to circulate. Let dry until the leaves crumble, 1–4 weeks. Store in an airtight container.
Oven-dry herbs, fruit, or vegetables
Spread herbs or sliced vegetables or fruit on a baking sheet lined with parchment paper (metal can affect the flavor) and place in a 150° F oven with the door slightly ajar. Check frequently and remove herbs when crumbly, fruit or vegetables when dry to your liking. Store in an airtight container.
Preserve in vinegar
There’s nothing like the tang of a good pickle. And there’s no easier way to infuse your ripe fruits and vegetables with that special sensation than with freezer pickles.
Pick a veggie or, though it’s uncommon, a fruit. I can’t think of any that won’t work.
Use any vinegar you like. Use pure sea salt without additives, or salt labeled “canning” or “pickling” salt. Additives in table salt may make your pickling solution—the brine—go cloudy.
Wash and chop your vegetables into whatever shape you want—disks, spears, wedges, whatever.
Some vegetables will be come out better if you blanch them—beets, Brussels sprouts, carrots, ginger, green beans, okra, peppers. For cucumbers, tomatillos, tomatoes, or turnips—no blanching.
Boil one gallon of water per pound of prepped produce. Add the vegetables, cover, and boil for 2 minutes (5 minutes for beets).
Flash-cool in ice water, then drain.
Put cooled vegetables in canning jars or similar-size tempered-glass containers with lids. Don’t use plastic—there are toxins there.
Add flavorings (optional, but go for it)
Add dry flavorings like chili peppers, bay leaf, cumin, mustard. No rules on this road—anything goes.
Add fresh flavorings, a great way to use your just-picked oregano, dill, or other herbs or peppers.
Make sweet or sour brine
There are countless recipes online for brines, both sweet and sour. Choose and make the one(s) you prefer.
Carefully fill jars (or containers) with brine to within 1/2 inch of the top of the rim, covering your fruits or vegetables completely. Place the lids on the jars (or containers) and refrigerate for at least 24 hours before serving. Pickles will keep in the fridge for up to 1 month.
Preserve in Olive Oil
This is another time-honored way to preserving vegetables, with the bonus benefits that make olive oil a prince of wellbeing. You can freeze vegetables in oil for up to a year, or preserve them at room temperature for 2 years or more.
Vegetables should be ripe, blemish free, clean, and dry.
- Cook the vegetables in stainless steel or non-reactive pans, for safety.
- Use only glass containers with lids that close tight.
- Fill the container with vegetables, then completely cover with extra virgin olive oil, making sure no food protrudes above the oil.
- Rub olive oil around the rim of the container and inside the lid to form a seal, and close tightly.
I hope these basics give you new ideas on preserving summer’s bounty for healthy eating come winter. My best tip? Add to these suggestions by consulting cookbooks or finding experienced preservers online.
- Thompson, Matthew. “How to pickle anything (no canning necessary)”Eating Well. Published July 26, 2012. Last accessed April 3, 2017.
- Firenze, Carol. “Preserving Summer with Olive Oil” The Olive Oil Source. Published September 01, 2010. Last accessed April 3, 2017.
- Christensen, Emma, et al.“10 Ways to Preserve Summer Fruits & Vegetables Without Canning” kitchn. Published August 12, 2013. Last accessed April 3, 2017.
- López-Alt, J Kenji. “The Food Lab: How To Preserve Fresh Spring and Summer Produce” SeriousEats. Published NA. Last accessed April 3, 2017.
- Durand, Faith. “Two Ways To Freeze and Preserve Fresh Herbs” kitchn. Published July 29, 2009. Last accessed April 3, 2017.
- “Preserving in Vinegar” healthy green KITCHEN. Published August 23, 2010. Last accessed April 3, 2017.