Cleaning or sterilizing
Fermenting vegetables doesn't need a sterile jar, just a properly clean one. Kombucha asks for one more step: sanitizing with hot water.
5 min read First steps Reviewed October 27, 2026 27 facts, each with its source
Three different things
They often get mixed up, but they aren't the same:
| What it is | When | |
|---|---|---|
| Cleaning | Removing dirt with soap | Always |
| Sanitizing | Heat or a product that inactivates microbes | Kombucha; optional for vegetables and kefir |
| Sterilizing | Leaving the jar with no living microbes | Only in some water-bath canning |
Cleaning is the physical removal of dirt with soap1. Sanitizing is applying heat or chemicals to inactivate the microbes you don't want2, and it only works on something already clean3: soap first, heat second.
Sterilizing is something else. It's a step in water-bath canning, and even there it's only essential when the processing time is under 10 minutes4. A ferment doesn't go through that process.
For vegetables, a good wash is enough
The bacteria that ferment sauerkraut, kimchi or pickles come with the vegetables themselves: they live on the surface of all fruits and vegetables5. You don't need a sterile jar. You need a clean one, and salt and acid do the rest.
That's what the NCHFP asks for: the container, the plate and the jars used as weights are washed in hot sudsy water and rinsed well with very hot water before use6. Kansas State asks the same for every surface and container7.
Other guides go one step further. The University of Illinois calls sanitizing a crucial step8 and suggests boiling equipment for 10 minutes9. The University of Georgia, for kimchi, washes with soap and then submerges equipment in water at 160 °F (71 °C) or hotter for at least 30 seconds10. It isn't required for vegetables, but it doesn't hurt with a secondhand jar or a lid you don't know.
Before you use a container, check it for cracks11: a crack can't be cleaned.
Kombucha and milk kefir
Kombucha: here you do sanitize. The NCHFP's tested recipe asks you to submerge clean equipment in water at 171 °F (77 °C) or hotter for at least 30 seconds12. Its FAQ warns that if sanitation is neglected, there's a risk of contamination13.
A dishwasher may work if it reaches 171 °F (77 °C)14. But any soap it leaves behind can hold back fermentation and the culture15, so rinse by hand if you see suds or smell detergent.
Milk kefir: clean, and no antimicrobial soap. Colorado State University asks you to wash your hands and equipment with regular soap, not antimicrobial16. Sanitizing with white vinegar or a fermentation sanitizer is optional17.
How to sanitize at home
- Wash first with hot water and soap, and rinse well.
- Pick a method:
- Better without bleach. Virginia Tech advises against sanitizing fermenting equipment with it, because its residues hold back the ferment's microbes18. If you use it anyway, diluted as the label says, rinse very well19. And never mix it with vinegar, an acid sanitizer or leftovers of a ferment: bleach mixed with an acid gives off chlorine gas20, and with vinegar, vapors that burn the eyes and lungs21.
- Use it right away, and don't dry it with a used towel: whatever you sanitized picks up what it touches.
When you do need to sterilize
Only in water-bath canning with a processing time under 10 minutes4. If you ever want to can a finished sauerkraut, follow the times of a tested canning recipe, and expect that heat to kill the live lactic acid bacteria22.
Fervida doesn't publish water-bath canning: it isn't fermentation. For a ferment kept in the fridge, the guides ask for a good wash, not a sterile jar6.
Hands, vegetables and afterward
- Hands: wash them with warm water and soap for at least 20 seconds before handling the ingredients23.
- Vegetables: wash them, but don't scrub hard, or you'll remove good bacteria the fermentation needs24. With cabbage, remove the outer leaves and rinse it under cold running water25.
- After a failed batch: throw out the contents, clean the container thoroughly and start again26. With kombucha, the tea and the SCOBY are discarded, and the container is cleaned and sanitized27.
Where every number comes from
Every number in the text leads to its figure: the exact sentence from the official guide it comes from, in its own language.
-
1
Cleaning is removing dirt with soap
“Cleaning is the physical removal of debris using soap.”
UC Davis, Department of Food Science and Technology · Common issues with fermented fruits and vegetables (v1.0, 15-mar-2022) · read on October 20, 2026
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2
Sanitizing is applying heat or chemicals to inactivate microbes
“the application of high heat or chemicals to inactivate undesirable microorganisms.”
UC Davis, Department of Food Science and Technology · Common issues with fermented fruits and vegetables (v1.0, 15-mar-2022) · read on October 20, 2026
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3
You can't sanitize something that isn't clean
“Sanitation cannot be achieved on equipment that is not clean.”
UC Davis, Department of Food Science and Technology · Common issues with fermented fruits and vegetables (v1.0, 15-mar-2022) · read on October 20, 2026
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4
Sterilizing jars is only essential for canning processed under 10 minutes
“When canning, sterilizing jars is essential only when processing times are less than 10 minutes.”
UC Cooperative Extension Master Food Preservers of El Dorado County (UC ANR) · Preserve It: Canning Basics. Sterilizing Canning Jars: It's not always necessary! Know when and why (July 2025) · read on October 26, 2026
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5
Lactic acid bacteria live on the surface of all fruits and vegetables
“by lactic-acid producing bacteria which are present on the surface of all fruits and vegetables.”
University of Illinois Extension · Fermentation handout (2020) · read on October 20, 2026
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6
Container, plate and weights: hot sudsy water, then a very hot rinse
“The fermentation container, plate, and jars must be washed in hot sudsy water, and rinsed well with very hot water before use.”
National Center for Home Food Preservation (USDA, University of Georgia) · Suitable Containers, Covers, and Weights for Fermenting Food · read on October 26, 2026
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7
Surfaces and containers washed in hot sudsy water and rinsed well
“Wash all surfaces and containers that will be used with hot sudsy water and rinse well before use.”
K-State Research and Extension (Kansas State University) · Taking a New Look at Fermented Foods (MF3491, June 2020) · read on October 20, 2026
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8
Sanitizing is another crucial step
“Sanitizing is another crucial step.”
University of Illinois Extension · Fermentation handout (2020) · read on October 20, 2026
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9
One method: boil for 10 minutes
“Sanitizing methods Boil for 10 minutes”
University of Illinois Extension · Fermentation handout (2020) · read on October 20, 2026
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10
Wash with soap, then submerge in water at 160 °F or hotter for 30 seconds
“To sanitize your equipment, wash it with soap and warm water, then submerge it in hot water that is at least 160 °F for at least 30 seconds.”
University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026
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11
Before use, check the container for cracks
“Before use, inspect the container for cracks.”
University of Minnesota Extension · Preserving food at home: Fermentation (reviewed 2026) · read on October 25, 2026
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12
Kombucha: clean equipment, 30 seconds in water at 171 °F or hotter
“Submerge cleaned equipment in hot water (at least 171°F) for at least 30 seconds to sanitize.”
National Center for Home Food Preservation (USDA, University of Georgia) · Kombucha Tea · read on October 20, 2026
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13
Without good hygiene, there is a risk of contamination
“risk of contamination if sanitation procedures are not observed”
University of Georgia Cooperative Extension (National Center for Home Food Preservation) · Crafting Kombucha at Home: Frequently Asked Questions (2026) · read on October 20, 2026
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14
A dishwasher may work if it reaches 171 °F
“If your dishwasher can reach a temperature of at least 171°F, it may be suitable for use.”
University of Georgia Cooperative Extension (National Center for Home Food Preservation) · Crafting Kombucha at Home: Frequently Asked Questions (2026) · read on October 20, 2026
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15
Soap residues can hold back fermentation
“soap residues, depending on how effectively the dishwasher can remove them, might interfere with the fermentation process and could potentially inhibit microbial activity.”
University of Georgia Cooperative Extension (National Center for Home Food Preservation) · Crafting Kombucha at Home: Frequently Asked Questions (2026) · read on October 20, 2026
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16
Kefir: wash hands and equipment with soap that isn't antimicrobial
“Wash hands and clean all equipment with soap (not anti-microbial)”
Colorado State University Extension (FoodSmart Colorado) · Understanding and Making Kefir · read on October 20, 2026
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17
Sanitizing with white vinegar is optional
“Optional: Sanitize equipment with white vinegar or fermentation-specific sanitizer”
Colorado State University Extension (FoodSmart Colorado) · Understanding and Making Kefir · read on October 20, 2026
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18
Better not to sanitize equipment with bleach: its residues hold back the ferment's microbes
“Do not use chlorine bleach to sanitize the equipment because the remaining chlorine and chloramine residues on the equipment could inhibit the growth of fermenting organisms.”
Virginia Cooperative Extension (Virginia Tech) · Vegetable fermentation (FST-328, reviewed 2025) · read on October 26, 2026
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19
If you use bleach, rinse well: residues hold back the fermenting bacteria
“If chlorine bleach is used, the equipment should be rinsed thoroughly to remove any residues which may inhibit the growth of fermenting bacteria.”
University of Illinois Extension · Fermentation handout (2020) · read on October 20, 2026
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20
Bleach mixed with an acid gives off chlorine gas
“When chlorine bleach is mixed with an acid, chlorine gas is produced.”
New Jersey Department of Health · Hazard alert: mixing cleaning products · read on October 27, 2026
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21
Bleach with vinegar gives off vapors that burn the eyes and lungs
“Vinegar – Produces harmful vapors, including chlorine and chloramine, which can burn the eyes and lungs.”
New Jersey Department of Health · Hazard alert: mixing cleaning products · read on October 27, 2026
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22
The heat of canning kills the lactic acid bacteria
“However, the high temperatures of canning will kill any beneficial Lactobacillus bacteria.”
University of Minnesota Extension · Preserving food at home: Fermentation (reviewed 2026) · read on October 25, 2026
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23
Wash your hands with soap for at least 20 seconds
“Always start by washing your hands with soap and warm water for at least 20 seconds before handling any ingredients.”
University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026
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24
Don't scrub vegetables hard: you remove good bacteria
“Do not vigorously scrub the produce; this can remove good bacteria needed for the fermentation process.”
University of Minnesota Extension · Preserving food at home: Fermentation (reviewed 2026) · read on October 25, 2026
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25
Remove the outer leaves and rinse the cabbage under cold running water
“Discard outer leaves. Rinse heads under cold running water and drain.”
National Center for Home Food Preservation (USDA, University of Georgia) · Sauerkraut · read on October 20, 2026
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26
After a failed batch, clean the container thoroughly and start again
“Clean the container thoroughly and try again!”
University of Illinois Extension · Fermentation handout (2020) · read on October 20, 2026
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27
Moldy kombucha: discard the tea and SCOBY, then clean and sanitize the container
“The tea and SCOBY should both be discarded, after which it is important to fully clean and sanitize the container that was housing them with the methods described above.”
University of Georgia Cooperative Extension · What’s the Word on Homemade Kombucha? (Circular 1312, 10-apr-2026) · read on October 20, 2026