Fermented foods can be a gift for your gut. Unfortunately (or fortunately), the versions with the highest numbers of beneficial bacteria tend to be homemade ones. Store-bought fermented foods are subject to plenty of regulations that keep them from having as many good microbes.
Luckily, humans have been fermenting foods at home (or hut) for thousands of years.
And, you can, too.
You might think you need fancy equipment or previous fermentation experience. But the truth is, you really only need a mason jar and appropriate ingredients. As long as you have some patience, many fermentations are easy, even for a beginner.
Mason Jar Fermentation: The Basics
Are mason jar ferments safe?
Yes! Since the first ferments, humans have been using far less sanitary and secure containers than glass jars.
What kind of container should you use?
You’re going to want a container that is made of glass or ceramic. A plastic container, even if “BPA free”, will likely leach synthetic nasties into your fermenting food over time. Metal, when exposed to the acidic environment most ferments result in, will rust.
Glass and ceramic can also be sterilized much more thoroughly than plastic. Simple glass canning jars (Ball, Mason, a used salsa jar from the co-op) will do just fine. The small batch size is nice too, especially to start out. Eventually, you can always upgrade to larger, water-sealed ceramic crock.
What kind of lid (and or airlock) should you use?
Something that keeps the vast majority of air out
To successfully ferment foods, you need to give your microbes an anaerobic (oxygen-free) environment. Without available oxygen, the environment forces the microbes to break down sugars for energy instead, making acids and alcohols.
As long as your foods are below the “brine” level, they are in an anaerobic environment.
During a ferment, you also don’t want to contaminate your food with microbes from outside of your container. Wild yeasts and mold spores may otherwise spoil your project.
Something that lets carbon dioxide out
When microbes break down sugars and other components, they will release carbon dioxide (CO2) as a byproduct. This means you need a way for the gases to escape, or enough room in your container for them.
This means you want air to be able to escape, but don’t want air to come in.
Enter, the airlock.
Airlocks are handy because they generally require little maintenance and may also reduce odors. Lids with water airlocks or water-less airlocks that fit mason jars can be easily found online or at a home-brew store.
Okay, but do you need an airlock?
Nope! Most ferments can be done with a normal jar lid (sanitized, of course) that is screwed on a bit loose. This allows gases to escape while also avoiding too much air exposure. The white plastic one-piece ones work well for this.
If you prefer to screw the lid on a little tighter, you’ll need to “burp” your jar regularly to avoid gas buildup. To do this, unscrew the jar just slightly, until you hear a small pop as gas get’s released. Re-tighten the jar. It may take a couple of days until there is enough gas to make a “pop”.
What other tools might you need?
- A fermentation weight or gate: Keeps your fermenting food below the brine level, and therefore protected from outside microbes and oxygen.
- Thermometer, pH strips, scale: Other goodies that will help you be more precise, though they aren’t needed.
How do you sanitize your containers, lids, and tools?
While sanitizing your tools for fermentation may initially seem intimidating, it’s essentially the same as washing dishes. If you have a dishwasher, run your supplies through it with soap and the hottest temperature. That should be good enough!
If you’re particularly paranoid, you can follow the dishwashing with baking your jars in the oven at 230 degrees F and then letting them cool. But, for the vast majority of ferments (especially short ones like these), this won’t be necessary. Your goal is to grow microbes, anyway.
Below are five recipes, with their source or inspiration linked in each featured image. Feel free to click on the link below the image for more detailed instructions similar to the given recipe.
Five DIY Fermented Foods (in a mason jar!)
1. Yogurt
Ingredients:
- Milk (whole or 2%)
- Yogurt culture starter (or 2 tablespoons of your favorite live culture yogurt)
Equipment:
- Two, single quart jars with lids
- A way to heat your yogurt (a crockpot, large pot in the oven or on the stove top)
Directions:
- Fill the jars with milk, leaving 1-2 inches of space at the top.
- Put them in a pot, and pour water into the pot until the jars are at least 2/3 covered.
- Simmer in the oven, on the stove top, or in an open slow cooker until temperature is 180 degrees F, or until a thick skin forms on top of the milk.
- Throw away the skin and allow the jars to cool until about 110-120 degrees (or until holdable). This will take approximately an hour.
- Add a tablespoon the starter culture (whether it’s a couple tablespoons of your favorite live culture yogurt, or a powdered starter you bought) to each jar and gently stir them in.
- Place the jars back into a warm environment and let them incubate for 8 hours. You can create a warm environment by putting them back in the crock (turned off) and covering them with the lid and a towel or two. Alternatively, place them back in the oven, or even fill a cooler with hot water and close them in.
2. Sauerkraut
Ingredients:
- Cabbage
- Sea salt
- Any other veggies or flavors you desire
Equipment:
- 1-Quart wide-mouthed jar with lid
- Fermentation gate/weight, or a jelly jar
- Optional airlock
Directions:
Summarized in the image above. For more detail, head to this site.
3. Lacto-fermented Oats
Ingredients:
- Oats, either old fashioned or steel cut
- Water (~1 cup for every 1 cup of oats or other grain)
- A couple of tablespoons yogurt with live cultures
Equipment:
- Jar with a lid, or even a bowl you can cover
Directions:
- Add oats, water, and a couple tablespoons of yogurt to a jar or bowl.
- Cover and let rest overnight, up to 48 hours.
- Cook similarly to how you normally would, though it will require less liquid and less time than you’re used to.
- The variations on this recipe are practically endless, as you can use the methodology with any overnight oats recipe.
- For more ideas on how to lacto-ferment other grains and increase their digestibility and goodness, go here.
4. Lacto-fermented Veggies
Ingredients:
- Sliced/chopped veggies
- 1.5 tablespoons sea salt
- 2 cups water
- Spices or herbs of your choice
Equipment:
- 1 quart wide-mouth mason jar
- Lid (plastic is better as metal will corrode over time)
- Optional fermentation weight or small cabbage leaf to help keep the veggies down
Directions:
- Pack veggies into clean jar, leaving about an inch of space at the top.
- Dissolve salt in water to make brine.
- Pour brine into veggie jar, covering veggies fully, but leaving about a half inch of space at the top.
- Close the jar tightly and place in a warm dark place for a couple of days.
- After the second day, “burp” the jar by loosening the lid 1-2 times daily.
- Start tasting on day 4, and ferment up to 10 days.
- Place in the fridge when its reached the tang level you like.
5. Kimchi
Ingredients:
- 1 medium Napa cabbage, about 2 lbs (savoy, green or any combo works too)
- 1/4 cup kosher, sea salt or other coarse salt
- 6 cups water
- 3/4 sweet apple (I used fuji), chopped
- 1/2 small white onion, chopped
- 1 1/2 inch ginger, chopped
- 1 – 2 cloves garlic
- 3 tablespoons Korean chili powder (gochugaru) or 1 tablespoon each cayenne & Hungarian paprika
- 3 – 4 scallions (green onions), sliced 1 inch
Equipment:
- Food processor or blender
- Glass jars with lids
Directions:
- Quarter cabbage and chop into ~2 inch pieces, then place cabbage in a an extra large bowl.
- Combine salt with 2 cups of lukewarm water, stir to dissolve, and pour salt water over the cabbage and add remaining 4 cups, stir.
- Let sit for 2-12 hours, with cabbage submerged (place a heavy dish on top to compress it if necessary), and mix every now and then.
- While cabbage is soaking, combine apple, onion, ginger and garlic in food processor/blender and process until fairly smooth.
- In a small bowl, mix the chili pepper with a small amount of water to make a wet paste.
- Once cabbage is ready, drain water, reserving 1/2 cup, and rinse well. Place cabbage back in large bowl, combine with all other ingredients and mix to coat with your hands (you may want to wear gloves) or a wooden spoon.
- Place the kimchi in glass jars or containers with lid, pack down to close air pockets and leave about an inch at the top. Top with remaining juices, add reserved brine if needed to cover vegetables.
- Let kimchi set at room temp for 24 – 36 hours. After 24 hours, open kimchi and pack the mixture down with a spoon. You may notice it bubbling, this is perfectly normal as the kimchi is fermenting. Taste every 24 hours and place kimchi in the refrigerator once you’re happy with the taste, usually after 48 – 36 hours. It should be tangy, spicy and slightly sweet.