For several years after I started cooking and farming, I avoided canning. It intimidated me. I was afraid of making someone sick. I was overwhelmed by recipes. I didn’t have any of the special equipment or know-how. Canning seemed complicated, technical, and elite. Best to leave it to the experts, I figured.
I couldn’t have been more wrong. With some help from my community, I mastered the basics and learned to can in a way that works for me. Canning can be approached both as an art and as a science. It’s important to know which parts you can fudge, and which rules need to be followed strictly for safety. I am the master of “just estimate it, that’s probably fine,” here to tell you about the technical process of canning.
Why Do People Can?
为冬天保存食物是最古老也是最必要的人类任务之一。Although we think of canning as quaint and historic, it is actually arelatively recent preservation tactic. Canning as we know it was invented by a Parisian cook named Nicolas Appert. Napoleon offered a reward for an invention that could preserve food to feed his army. Appert figured out how to preserve food by heating it in glass jars, sealed with wax.
Home canning didn’t arrive until the late 1800s, when John Mason invented the reusable home canning jar. The heyday of home canning was relatively short, lasting less than a century, between the 1860s and late 1940s. The supermarket replaced the need to can at home. Still, many households made applesauce and jam.
My grandmother, like most people of her generation, practiced something called open-kettle canning. I never met her—she was born in 1920. From all my mom’s stories about her, she was a tough, Depression-era woman, who didn’t hold with any new ideas like women’s lib, or water-bath canning.
In kettle-canning, the empty jars were boiled, the filling was boiled, the hot filling (jam or pickle brine, etc) was poured into the steaming jars and there was no need to process the jars any further. Grandma would put lids on (also boiled), let them seal themselves as they cooled, and my mom claims she never had anything spoil. Today, health professionals, USDA officials, and most home canners haverejected kettle canning and other traditional methodsas unsafe.
There are two types of modern canning that my grandmother scoffed at: water bath and pressure canning. They are used for different types of preserves.
Water-bath canning is for high-acid and high-sugar foods like fruit, jams and pickles, which are at low risk of spoiling and causing illness. Pressure canning, which heats jars to a much higher temperature, is used for higher-risk foods like non-pickled vegetables, garlic, and anything with meat in it. The process is similar for both methods. Let’s take a look.
Choosing A Recipe
The most important step tosafely canning food是遵循一个可靠的配方。Canning recipe books abound, but my favorite for beginners isPreserving the Harvestby Carol Costenbader, which covers not only canning but also freezing and drying. Costenbader provides a comprehensive introduction to the science of canning and how to do it safely.
你也可以在网上找到食谱,但要确保它是可信的来源,尤其是水浴罐的食谱。我喜欢和我知道是熟练和经验丰富的罐头工人的朋友交易食谱。
If you are water-bath canning, a trusted recipe is a must. Since boiling temperatures are not enough to killbotulismspores, canning relies on acidity to fight that particular microbe. It is important to get your ratios right. Since pressure canning heats jars as high as 240 F, recipes and vinegar ratios are not quite as important. Still, you’ll want to follow advised processing times and pressures!
Related Post:Best Canning Recipes
You can’t always find exactly what you want in a recipe. This weekend, my partner and I spent a long afternoon walking around a grocery store picking up canned vegetables and reading the ingredients, because we couldn’t find a recipe we liked for preserved artichoke hearts.
We ended up compromising and going with an established recipe, because neither of us had canned artichokes before, and they are a low-acid food. An experienced canner will sometimes combine elements of trusted recipes to make new concoctions, but we weren’t ready for that, at least with artichokes.
For the record, I don’t like recipes, they stress me out. I would much rather improvise, and I struggle with the discipline it takes to can or bake from a recipe. Here are my tips on following recipes if you are a disorganized and impulsive cook like me.
Tips For Working With Canning Recipes
- Make your partner do all the measuring. Just kidding! Actually though, if you go cross-eyed like I do when I try to follow recipes, get a buddy to help you. Working with a friend is more fun anyway, and you can double check each other and help each other when you get frustrated.
- Get all the ingredients out beforehand. Those fancy art photos on food blogs of ingredients on a cutting board? Do that. It makes sure you won’t forget something.
- Use a highlighter. Often recipes combine the essentials (10lbs tomatoes, 1 onion, 3 tablespoons vinegar) with the optionals (parsley, celery seed, garlic powder, oregano and basil to taste). I find that doubles the challenge of recipes for me, so I like to highlight the essentials, either in a book or a Word document.
Steps For Prepping Your Containers And Food
Once you have a recipe you like, move on to the actual preparation.
1. Wash Your Glass Jars and Rings
Do this even if they are already clean. I usually just load up the dishwasher and run it. Jarsdon’t actually need to be sterilized, since unlike my grandma, we will be sterilizing them during the processing step.
Followmanufacturer’s instructionsfor jar lids—most metal lids are one use only. You can buyreusable canning lids,但是我从来没有试过。我的一个朋友抱怨说,检查可重复使用的塑料盖子的密封性没有那么容易(详见关于检查密封性的讨论)。
2. Wash and Prepare Your Vegetables
这通常是一个非常耗时的步骤。如果你有帮手,建立一条装配线。有些食谱要求在装罐前将蔬菜烤熟或焯水。准备任何可以覆盖蔬菜的液体,有时是沸水,有时是盐水。
3. Pack the Jars
This can be a challenge. You may not fit as much in a jar as you would like, but err on the side of less full rather than more full. Don’t be afraid to pack them tight, as long as you leave a headspace—space for the liquid to expand as it boils without exploding the jar.
The smaller you chop pieces typically the more volume you will fit in a jar. You will get more cucumbers in a quart if you are making bread-and-butter pickles sliced in rings than dill pickles sliced in spears.
4. Add Spices
在这里你不需要遵循一个食谱——如果你不喜欢芥末籽,就不要放芥末籽!这是你的创造。混合香料是自制泡菜和蜜饯真正闪亮的原因。你唯一不应该改变的是添加盐和糖的量,因为这些都是防腐剂,可以防止食物变质。
5. Add Liquid
Pour in the liquid until it covers the vegetables, being sure to leave a headspace! Headspace is the empty room at the top of the jar, above both the vegetables and the liquid line. It allows room for water to expand during the heating process without breaking the jar.
Then wipe the rims with a clean rag or paper towel, and put on the lids and rings. Don’t tighten the rings too tight. If you have overpacked your jars it is better for them to leak than explode.
Hot Packing Vs. Cold Packing
Hot Packing
Adding boiling water or hot brine to packed jars. More common for canning.
Cold Packing
Brine is boiled and then cooled before being poured into jars. More common for fridge pickling.
Water-Bath Canning
一旦你有了自己喜欢的食谱,水浴装罐就很简单了。It doesn’t require much special equipment—in fact the only things you really need are a big pot andjar tongs! You also need some way to keep the jars off the bottom of the pot, so that they don’t crack with the direct heat. There arecanning racksdesigned for that, but you can alsouse extra metal lid-rings, or bamboo cooking skewers.
- Fill the pot with enough water to cover the jars completely and heat to a rolling boil before putting anything in. If you are cold-packing, turn down the heat and let the water come to a gentle simmer, not quite boiling, or you risk cracking your jars. If the jars are hot packed, you can put them straight in the boiling water.
- Once your jars are full, with the lids on, use the tongs to put the jarsgentlyon the bottom. They crack easily if dropped. If you do break a jar, don’t worry. Lift the other jars gently out, put them on a cooling rack or towel, empty the pot (careful! It has broken glass in it!), and start again.
- Let the water come back to a full boil before starting your timer. Allow to boil for however long the recipe calls for. The water should cover all the jars the entire time. When the timer goes off, turn off the heat and lift the jars out using the jar tongs. Set them aside to cool.
- The jars aren’t sealed yet, so don’t mess with them! As they cool, you will hear their seals popping. The cooling air inside creates a vacuum, and sucks the metal lid in.
By the time they are room-temperature, all the seals should be concave, and not change when you tap them. If any have not sealed, put them in the fridge and eat them within 3 to 5 days.
Pressure Canning
Pressure canners,unlike pressure cookers, allow you to heat food above the boiling point. This will kill microbes like the one that causes botulism without the aid of vinegar and salt. A pressure canner will open up a whole new world of foods you can preserve.
My partner and I only recentlybought a pressure canner, and it’s been a game-changer. So much more stuff can go into them, and you don’t have to worry about exact ratios of preservatives like salt, vinegar and sugar. Recipes look more like “pack jars, leave 1 inch headspace, fill with boiling water, can for 35 minutes.” I love it!
使用罐头机真的很简单。再一次,遵循制造商的说明。最难的部分是在整个加工过程中保持正确的压力。We use a pressure-gauge canner, whichrequires more supervision and adjustment than the weighted-gauge canners.
Pressure canners do most of the work for you, but you need to monitor the pressure. At sea level, 11 pounds per square inch (PSI) is standard. The pressure corresponds to the heat inside the canner. At higher elevations, follow aconversion table. To keep the correct pressure, you have to adjust the heat of the burner. Too high and you will overcook your food. Too low, and you have to start timing from zero again (and if you do that too many times, youstillend up with overcooked food).
第一次使用压力罐时,我们花了大半个小时的加工时间来调节温度,因为压力表在11到15之间摆动。诀窍是在达到你想要的温度之前降低热量,因为这有一个延迟的响应时间。即使你把温度调低,罐头内的热量仍会继续上升(反之亦然)。在我们的燃气表中,维持11 PSI的最佳温度点略低于中等和低的中间值。每个炉子都不一样。一旦你找到了你特别的炉子,这一步就会变得容易得多。
Presto 23-Quart Pressure Canner and Cooker
Made from high-gauge aluminum, the Presto canner and cooker comes with a 12-year limited warranty. Priced at less than $100, it’s a good starter canner.
Depending on how long the recipe calls for maintaining pressure, the whole canning process from closing the canner to opening it takes between and hour and an hour and a half. Bring a book into the kitchen or play a game of cards, because during that time you won’t need to do much except keep an eye on the pressure gauge.
一旦所有的辛苦工作都完成了,你就可以在一个下雨的秋天下午享受你的厨房变得多么温暖和潮湿了!就像水浴罐装一样,当它们第一次从罐头里出来时,盖子是不密封的。放置至室温,然后取下戒指。
A Note on Canning Meat
很长一段时间以来,家里的肉罐头一直让我担心,但仔细想想,金枪鱼罐头和鸡汤罐头至少半个世纪以来都是厨房的主食。最重要的是,所有的肉都需要压力罐装。除此之外,这很简单,并不比罐装其他东西更危险。
I recommend that you readthe USDA’s guide to pressure canning meat and seafood. Some meats and especially fish are packed raw, to prevent overcooking. Often USDA standards call for lean meat, or to remove excess fat, since fat particles can cause uneven heating and interfere with the sealing process. All I can say is stick to the guidelines but don’t stay up at night worrying about it.
Storing Canned Food
Once your jars are sealed, label them! Include the month, year and contents. Like my mom always said about labelling photos of friends (obsolete advice in the era of internet tagging), even if you are sure you will always remember, write it down anyway!
Remove the ringsand wipe down the outsides of the jars. Store in a cool, dry place. In damp weather, the metal lids and rings can start to rust if they are being stored someplace like the garage with bad insulation. I know people who store their canned goods under their bed!
Check on your jars. Hopefully, you will be eating out of them, so every time you go to get a new jar, inspect it. It’s easy to tell if any of the seals have popped or lids are loose. The metal lids will just have “popped” up, no longer concave, and they will come off easily. Canned goods should always be hard to open. Throw any poorly sealed jars away immediately.
Eating Canned Food
When you take a jar out to eat it, rejoice! It is so exciting to eat something you canned yourself. But before you dip in, take a few basic precautions.
- 检查封条是否还紧——应该很难打开!你可能需要使用一把黄油刀或一把教堂钥匙。
- Look at it—is there any visible mold, black, white or pink spots, or other discoloration? Compare it to other jars in your batch, because there may be some change in color over time naturally.
- Smell it—does it smell like it did when it went into the jar? If the seal was good, and it looks and smells fine, congratulations, it is good to eat!
Tips For Beginning Canners
如果你仍然感到不知所措,没关系!就像任何技能一样,人们的能力也有不同的水平,也有不同的练习方法。你不需要马上成为专家。我奶奶从来没有让任何人生病,她甚至没有采取今天罐头工人认为的基本安全预防措施。
Start With Basic Recipes
泡菜和果酱是不错的选择。
Find A Buddy
They don’t have to be more experienced than you. It makes a huge difference to just have another person in the kitchen to turn to and say “Does this look right?”
Find A Book Or A Youtube Mentor
Preserving the Harvestis great. If you are up for something more technical, theUSDA’s Complete Guide to Home Canningis comprehensive and free online.Michigan StateandOhio StateUniversities both have canning series on Youtube.
Don’t Buy Fancy Equipment Right Away
You may find that you don’t have the patience or temperament for canning. That’s ok!
People choose to can for all sorts of reasons. Some people like to know exactly what’s in their food. For some people, it is the cheapest option. Some hate to see food composted.
Some people love the meditation and satisfaction of the kitchen. For my grandmother, canning was necessary if her family was going to have jam or pickles through the winter.
I never got to ask her whether she actually liked doing it. Today, we have the option of buying pickles at the store. If you don’t like it, don’t make yourself do it. Life is too short.
What You Need To Start Canning
- Jars:It’s easiest to buy these at the grocery store, but youcan get them from Amazon too. Many canners recommendwide mouth jars, simply because it’s easier to get the food in.
- Lids:The jars you buy will come with an equal number of lids. Eventually you’ll use more lids than jars, so you may want tobuy some extra ones. Lids are one-time use only.
- Rings:你买的罐子也会有相同数量的盖子。这些圆环在加工过程中固定盖子,大约24小时后可以取出。理论上,你只需要和罐子一样多的戒指。
- Big Ol’ Pot:You need a big deep pot for canning, so the jars are completely submerged during processing. A good size to start with is an11-quart pot. You can also buy canning pots by Granite Ware that come with their own racks. They come in12-quartand21.5-quartsizes. Don’t use a bigger pot unless you have access to the massive stoves of a restaurant kitchen—on a home stove anything bigger will take ages to heat up.
- Widemouth Funnel:For pouring things into the jars without making a huge mess. Stainless steel is a good choice because food won’t stick to it and it won’t warp over time like plastic.这个不错,不到10美元。
- Canning Rack:The rack holds the jars in place during processing. If they’re jouncing around they could break. This version with high handles for easy extractionsells for around $20.
- Jar Lifter:Pretty self-explanatory. You need a tool to pull the hot jars out of boiling water. You can usespecial jar liftersorrubber-tipped tongs.
- Pectin:This lovely natural sugar helps turn fruits into jelly. It’saround $7.50 a box.
- Labels:你必须写下你罐装的食物,尤其是你什么时候罐装的。Ball Canning sells labels that willdissolve when you wash your jars. Or, check out somecool custom labels on Etsy.
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