How to Make Sauerkraut in a Mason Jar (No Crock, No Grandma Required)

Two ingredients. Cabbage and salt. No crock, no root cellar, no German grandmother whispering over the pot.

Shred a cabbage, weigh it, add salt equal to 2% of the weight, and squeeze the daylights out of it until it makes its own brine. Pack it in a mason jar under that brine. Walk away for three or four weeks. Come back to sauerkraut. That's honestly the whole recipe!

One wrinkle, and it's a fun one. The official USDA recipe was written for a crock, and it packs one instruction your mason jar literally cannot obey. Not "shouldn't." Can't. We'll get there.

The whole job: about twenty minutes

• Shred it. Peel off the sad outer leaves (save one good one!), quarter, cut out the core, slice into thin ribbons.
• Weigh, then salt. Bowl on the scale, hit tare, take the grams, times 0.02. There's your salt.
• Squeeze like you're mad at it. Five, ten minutes, bare clean hands, until it goes floppy and a puddle shows up in the bottom of the bowl. That puddle is the brine. Do NOT pour it out. I mean it.
• Pack it tight. Handful, tamp, handful, tamp, until the brine floods over the top. Fill to about 75 to 85 percent. No higher, trust me.
• Weigh it down, cap it loose. Something heavy holding every shred under the liquid, then a lid that burps gas out but won't let air in.
• Wait. Three to four weeks at 70 to 75 F. Taste it at a week, then weekly. Done is whenever YOUR mouth says done.

How much salt? Your tablespoon is a liar

Every recipe online tosses you a number in tablespoons. One per head. One per one-and-three-quarter pounds. Three per five pounds. They're all just guessing at the same thing: 2 to 2.5 percent salt by weight.

Why so vague? Two reasons gang up on you. Cabbages aren't standardized, so yours might be a scrawny pound-and-a-half or a five-pound bruiser, which turns "one tablespoon per head" into a coin flip. And here's the sneaky part: a tablespoon of salt isn't even a fixed amount of salt. Fine canning salt is about 21 grams a tablespoon, coarse kosher more like 18, flaky stuff less. Same spoon, different salt. Rude.

Want it to get weird? The USDA recipe can't agree with itself. Its ingredient list says 25 pounds of cabbage to 3/4 cup of salt, which is 2.2 percent. Its directions right underneath say five-pound batches at 3 tablespoons each, which is 2.8 percent. Same recipe, a 25 percent gap between two lines on one page! Both are safe, both make good kraut, the saltier one just tastes saltier. So relax.

Which is exactly why you weigh instead of scoop. Plop the bowl on an Escali Primo Digital Kitchen Scale ($29.95), tare it, dump the cabbage in, times the grams by 0.02. One quart jar takes about two pounds of cabbage, and two pounds is 907 grams, so 2 percent is 18 grams, a scant tablespoon. Now you've got a number to scribble on the lid and nail again next time. Beats a coin flip.

The one crock rule a mason jar can't follow

Okay, the fun part. Read the USDA procedure and you'll hit this line about your container: "Be sure it is deep enough so that its rim is at least 4 or 5 inches above the cabbage."

A quart mason jar is under seven inches tall. Leave five inches empty on top and congrats, you've made a single cup of kraut in a quart jar. So jar fermenting just... breaks the rule. On purpose. Here's the thing: all your fermenting gear exists to make up for the headroom you gave up.

That's the whole reframe, and it's kind of a great one. The weight, the airlock, the fill line, none of it is fussy hobbyist nonsense. It's all doing the job that five inches of empty crock used to do for free. Kraut is a bubbly, foamy, ENTHUSIASTIC ferment in that first week, and a crock has room for the party. Your jar doesn't, so the party ends up on your counter. Unless you gear up!

Four jars, four colors. That's not decoration, that's how you tell the kraut from the kimchi three weeks from now.

Crock, jar, or "eh, I'll figure it out"?

That last column works, honest. Want to try one cabbage this weekend before spending a dime? Go for it! Just peek at the "fussing" row: every dollar you skip on gear, you pay back in daily babysitting.

Above the brine is trouble. Below it is sauerkraut.

If you remember one line, that's the one. Good bacteria love it airless down in the brine. Mold and yeast want air up top. So a stray shred bobbing on the surface isn't an eyesore, it's an open door.

• The free fixes. Fold that saved cabbage leaf over the top like a little blanket, wedge in a small jelly jar, or flop a sealed bag of leftover brine up there (brine, not water, so a leak won't water down your batch). All fine! Just know the USDA says jars-as-weights means checking and skimming a couple times a week, since a jar can't cap the whole surface the way a real weight can.
• Or an actual glass weight. Pickle Pebbles by Masontops ($21.99), four to a pack, regular AND wide mouth, sized to drop under the jar's shoulder and pin the whole surface flat. Solid glass, nothing leaches, see-through so you can spy on the process. Best bit? A little raised nub on top to grab. Ever tried fishing a slick flat disc out of a full jar of brine? You'll love that nub real fast.

See the little grip? That's the whole ballgame. A plain disc is great until it's time to get it back out.

Related reading: Fermentation Weights: Why Your Vegetables Float, and What It Actually Costs You →
The deep dive on that floating problem: kahm yeast vs mold, the one cabbage-leaf trick, and how to size a weight to your jar.

And to pack the cabbage tight enough that the brine rises over it, a wooden tamper stomps a spoon flat. The Acacia Wood Pickle Packer ($17.99) is 10 inches of solid acacia with two ends, a fat 2.5 inch face for wide jars and a 2 inch face for regular. One stick, every jar you own! Fun bonus: off-season it moonlights as a cocktail muddler.

Burp it, or don't: the airlock question

Fermenting cabbage cranks out carbon dioxide, buckets of it that first week, and it has to escape somewhere, so if you screw a lid down tight the pressure just builds until the jar weeps brine down its own side. You either crack the lid every day (that's "burping"), or you slap something on top that vents itself. The old-school move is a water-channel airlock, that plastic tower from homebrew kits. Works! Also several inches tall and always thirsty for a water top-off. Meh.

Tidier answer: a one-way silicone valve. Pickle Pipes by Masontops ($21.99) are a chunky silicone cap with a nipple valve that pops open under pressure and snaps shut the rest of the time. Gas out, air stays out, you do nothing. BPA-free, dishwasher-safe, done. One gotcha that trips everybody up: you still need the metal screw band off a regular canning lid to hold it on.

Related reading: Superb vs Ball Canning Lids: The Honest Comparison →
Since you'll want those bands anyway, here's our take on the two brands.

How long? And how do you know it's ready?

Temperature runs the clock, not the calendar. Tape these numbers inside a cupboard:

• 70 to 75 F: ready in 3 to 4 weeks. The sweet spot.
• 60 to 65 F: 5 to 6 weeks. Slower, and lots of folks swear it tastes better.
• Below 60 F: might not go at all.
• Above 75 F: fast, but it can go mushy.

Notice 70 to 75 F is your house in July, not your house in a Michigan February. Kitchen sitting at 64 all winter? You didn't mess up! Yours just takes six weeks instead of three. Park it somewhere steady and forget it exists.

Ready is a taste thing, not a timer thing. Bite some at a week, then weekly. Early on it's salty cabbage with a whisper of sour, and finished it's properly tangy with the raw crunch gone. Your mouth is the only judge that counts.

White stuff on top. Freak out, or skim it?

Skim it, almost every time! This is the classic first-batch scare, and the giveaway is texture, not color:

• Flat, matte, white, filming across the whole top? That's kahm yeast. Harmless. It shows up when the sugars run low and the pH drops. Skim it, carry on, your kraut's fine. It does taste funky if it gets thick, so don't let it.
• Raised, fuzzy, or in color (blue, green, black, pink)? Mold. That one's for the compost. Sorry.

Both mean the same thing: something touched air. Which is the whole reason the weight isn't optional and the fill line isn't a vibe.

It's done. Fridge it, or can it?

Fridge it. Swap the airlock for a solid lid, park it in the fridge, and the USDA says finished kraut keeps for months in there. Cold doesn't stop the ferment, just slows it to a crawl, so it keeps getting a hair more sour, and everything living stays alive, which for a lot of us is the whole point.

Or can it. Want it shelf-stable? Finished kraut is high-acid, so it's a boiling water bath, NOT a pressure canner. USDA times at sea level: 20 minutes for raw-pack pints, 25 for quarts (10 and 15 hot-packed). The heat kills the live cultures, so that's the trade.

Related reading: Pressure Canner vs Water Bath: One Rule Decides What You Can Safely Can →
Why finished kraut's fine in a water bath, and what absolutely is not.

Okay, so what do we actually stock for this?

Real talk first: we don't carry a fermentation crock right now. At all. We used to stock a one-gallon stoneware crock and we let it go, because jars just win. You make a single quart in a jar you already own, decide if you even like the stuff, and skip the five-gallon monument in the basement.

• Complete Wide Mouth Fermentation Kit by Masontops ($54.99), the whole shebang: 4 Pickle Pipes, 4 Pickle Pebbles, the acacia Packer, plus a recipe book. Four jars going at once! Read this bit twice: it's wide mouth ONLY, and the box flat-out says jars and screw bands aren't included. You bring those.
• Pickle Pebbles ($21.99) and Pickle Pipes ($21.99) sold on their own, both mouth sizes.
• Acacia Wood Pickle Packer ($17.99) solo. Hand wash, dry, rub in a little mineral oil now and then.
• Escali Primo Digital Kitchen Scale ($29.95), because the 2 percent is the recipe and the tablespoon is a rumor.
• Regular Mouth Quart Mason Jars, 12 count ($30.97). These are regular mouth, so pair them with the regular mouth Pebbles and Pipes.

One quick thing before you check out: go see if your own jars are regular or wide mouth. Most kitchens have a mix and nobody's ever noticed. Way better to find out now than after the box lands!

Straight off the maker's spec sheet. The wide mouth Pebble is 2.75 inches across and 3/4 inch thick, heavy enough to hold, thin enough to leave room for the kraut.

FAQ: the sauerkraut stuff people ask us at the counter

Do you need an airlock or a special lid to make sauerkraut in a mason jar?

Nope. A plain canning lid and band works fine if you loosen it once a day to let the gas out, which fermenters call burping. A coffee filter under the band works too. A silicone airlock like a Pickle Pipe just does the burping for you. It's a convenience thing, not a safety thing.

How much salt do you need for sauerkraut in a quart mason jar?

Aim for 2 to 2.5 percent of the cabbage's weight. Two pounds of shredded cabbage fills a quart, and 2 percent of that is about 18 grams, a scant tablespoon of fine canning salt. Weigh it instead of scooping, since canning salt is about 21 grams a tablespoon and coarse kosher is closer to 18. Skip anything with iodine or anti-caking agents.

How long does sauerkraut take to ferment in a mason jar?

Roughly 3 to 4 weeks at 70 to 75 F, or 5 to 6 weeks at 60 to 65 F. Below 60 F it might not go; above 75 F it's fast but can turn soft.

Can you use a regular mouth mason jar for sauerkraut, or does it have to be wide mouth?

Regular mouth is totally fine! Wide mouth is just easier to pack and get a hand into, which is why the kits lean that way, but the cabbage couldn't care less. Only catch: match your gear to your jars, because weights and airlock lids come in both sizes and don't swap.

More from our pickling and fermentation series

• Fermentation Weights: Why Your Vegetables Float, and What It Actually Costs You - the deep dive on the weight that does the work here.
• Pickling vs Fermenting: 3 Ways to Make Pickles, and Only One Needs a Canner - where kraut fits alongside refrigerator and canned pickles.
• Regular Mouth vs Wide Mouth Mason Jars: There's No Wrong Answer - the jar question this whole method keeps bumping into.

Everything for jar fermenting, in one spot

Shop Pickling and Fermentation supplies →
Weights, airlocks, tampers, kits, jars, bands. Current stock and mouth size on every product.

A quart of homemade kraut runs you about three bucks of cabbage and twenty minutes. Hate it? You're out three bucks. That's a cheap way to find out you love it! And if it goes sideways halfway through, email us at support@kooihousewares.com and tell us what your jar looks like. Somebody here has absolutely made that same mistake.