A Story From the Field: Thirty Jars of Pla Ra and the Hardest Decision

"Auntie Boonma" leads a village women's group that makes pla ra, the pungent fermented fish used in som tam and countless Isan and central Thai dishes, along with pla som, a sour fermented fish. Their village sits on the bank of the Chao Phraya River in In Buri district, Sing Buri. Behind her house stands a shed with a corrugated metal roof. Under it, about thirty earthenware jars and lidded plastic fermentation drums are lined up, each one holding a different batch. Some have been fermenting for almost a year. At the front of the house, a small stall sells pla ra by the scoop, pla som and chilli pastes to neighbours and to drivers passing through.

At the end of September, the river spilled over its banks and water crept slowly into the village. Group members managed to lift some of the smaller drums onto a raised bamboo platform, but the large earthenware jars, full to the brim with fermented fish, were far too heavy to move. Inside the shed, the water rose until it covered the jars halfway and then stayed there for almost two weeks.

On the day the water receded, Auntie Boonma walked into the shed and had to pull a cloth over her nose. The smell was not the familiar, savoury aroma of good pla ra. It was a rotten smell mixed with mud and stagnant water. The packed-earth floor had turned into sticky mud. Many jars had a ring of silt around their mouths. The cloth covers and string tied over the jar openings were soaked through and fuzzy with white mold. The bamboo racks used for drying fish had black mold spots, and swarms of flies circled the whole shed.

Some members suggested, "The jars with lids still tied on are probably fine. It would be such a waste to throw them out." But Auntie Boonma knew that regret over lost stock must never come before the safety of the people who eat it. Most of the group's customers live in the same community, and some buy pla ra every day to make som tam for their children and grandchildren.

Auntie Boonma's story is a realistic scenario that reflects the real problems community fermented-food producers face after a flood, whether they make pla ra, pla som, naem sour pork, pickled bamboo shoots, pickled vegetables or home-brewed fish sauce. This article explains what should be thrown away, what can be washed, and how disinfection fogging and ozone treatment help bring the shed itself back into working order.

Why Fermentation Sheds Need Special Care After a Flood

Fermented foods such as pla ra rely on salt and a carefully managed population of microbes. A flood brings outside germs into that environment. Water that has flowed across rice fields, through animal pens, latrines and drains carries bacteria, waste and other contaminants. When floodwater covers a jar or drum, even one with its lid still on, nobody can guarantee that water has not seeped past the rim, through the cloth cover or through tiny cracks in an earthenware jar.

Fermentation is also a slow process. Producers often cannot tell by smell or appearance alone whether contamination has occurred, because fermented fish already has a strong odour and a soft texture. That is precisely why the safest rule is a simple one: if the water reached it, it goes.

Health risks

• Diarrhoea and food poisoning. Germs from sewage, such as E. coli, can contaminate flooded fermented food and then reach many consumers through a single batch.
• Leptospirosis. Sheds that store fish and food attract rats. During a flood, rat urine mixes with the water and mud. Members who go in to clean must wear rubber boots and gloves, especially if they have cuts or scratches.
• Flies and other carriers. The smell of rotting fish and standing water draws huge numbers of flies, which can carry germs to neighbouring homes and food stalls.
• Mold and allergies. Bamboo racks, cloth covers and wooden walls that stay wet for days become breeding grounds for mold. Members with allergies or asthma may cough and struggle to breathe while working in the shed.

Risks to income and community trust

A women's group sells its products because people trust it. Customers know who makes the food, where the fish comes from, and believe it is made cleanly. If someone gets sick after eating pla ra sold after the flood, word will spread around the subdistrict within days. The damage to the group's reputation could easily be greater than the value of every jar in the shed. Throwing away flooded stock is therefore an investment in the group's livelihood over the long term, not just a loss.

There is also the question of the group's own members. Many depend on the income from pla ra sales to pay for school fees, fertiliser and household costs. Restarting production quickly matters, but restarting in a shed that still smells of rot and harbours mold would only lead to new problems later. A careful, ordered recovery protects both health and income.

Step One, Done by the Group: Firmly Discard Everything the Water Touched

Before talking about fogging or ozone, it must be said clearly: disinfecting a shed cannot make flooded food safe again. The approach we recommend is this.

• Throw away all of it: every jar and drum of pla ra, pla som, fish sauce and any other fermented food the water reached, even if the lid is still on. Also discard fresh fish, salt, roasted rice powder, rice bran and every ingredient that touched the water, along with any bags and tubs of packaging stored in the shed.
• Throw away or replace: jar cloths, string, woven baskets, bamboo racks with deep mold, wooden paddles used to stir the fish and wooden chopping boards. These materials absorb dirty water and mold into their fibres.
• Wash and consider reusing: earthenware jars and plastic drums without cracks. Empty them, scrub them several times with clean water and detergent, and dry them completely in the sun. Jars that are cracked or whose inner surface absorbs water should be discarded.
• Dispose of it responsibly: large amounts of pla ra smell strongly and attract animals. Ask the municipality or subdistrict administrative organisation where organic waste should go. Never pour it into the river or canals.

After sorting, shovel the mud out of the floor, wash the floor, walls and shelving with clean water, and open the shed to let wind and sunlight in. Then move the washed containers, new bags of salt and all equipment out of the shed before the WHD team arrives to disinfect and ozone-treat. Our work is carried out only on an empty shed.

It is worth photographing the shed and the discarded stock before disposal. Pictures help with any assistance or insurance claims and give the group a record of what was lost, which is useful when planning the next season.

Why Washing Alone and Traditional Fixes May Not Be Enough

Pouring bleach onto muddy floors. Bleach loses much of its strength when it meets large amounts of organic matter such as mud and fish remains, so disinfection is patchy. A lingering chlorine smell could also interfere with the next fermentation batch.

Burning or smoking the shed to drive off the smell. Smoke may chase insects away for a while, but it does not disinfect surfaces, and it risks setting fire to a shed full of bamboo and straw under a metal roof.

Sprinkling lime or ash over everything. This absorbs some moisture but does not remove the rotten smell soaked into wooden walls, and it cannot reach gaps under the roof or the joints of the racks.

Waiting for the smell to fade on its own. The smell of rotten fish soaked into wood and soil can linger for months and keeps attracting flies, while the group wants to start a new batch as soon as possible to earn an income again.

Covering the smell with a new batch. Some producers are tempted to start fermenting again immediately, reasoning that the new pla ra will mask everything. But mold and contamination left in the shed remain a risk for the new batch, and the group gains nothing by hiding a problem rather than fixing it.

The Solution: CHEMGENE HLD4H Disinfection Fogging and Ozone Treatment of the Empty Shed by WHD

Once discarding and washing are complete, the World Health Disinfection (WHD) team steps in where hand cleaning cannot fully reach, using two methods that complement each other.

1. Ultra-low-volume (ULV) disinfection fogging with CHEMGENE HLD4H disinfectant. Fine droplets reach roof frames, wooden walls, shelf joints and the space under racks, helping reduce bacteria, viruses and mold on surfaces that have already been washed.

2. Ozone shock treatment with a controlled ozone generator. Ozone gas spreads through the shed, breaking down the molecules that cause rotten, muddy and musty odours soaked into the wood, and reducing airborne mold spores. For very open sheds, the team assesses the site and temporarily closes off openings where possible, or concentrates on fogging if the space cannot be enclosed.

How the service works for fermentation sheds and community food shops

1. Site survey. We look at the shed structure, wall and floor materials, how high the water rose, and the front stall used for selling.
2. Confirming preparation. All fermented food, ingredients and containers have been moved out or discarded, mud removed, and floors and walls washed.
3. Disinfection fogging. The team fogs the floor, walls, roof frame, shelves, the front stall and the rubbish area.
4. Ozone treatment. The space is closed and treated for a period suited to its size. No people, pets or plants may be inside.
5. Ventilation. Doors and openings are opened until the ozone has broken down, before members go back in.
6. Re-check and advice. The team checks for remaining odour, mold and damp spots and gives advice on raising jars on platforms and protecting stock in future.

Disinfection fogging and ozone treatment help reduce germs, mold and odours in the shed, but they are not a certification of food safety and do not replace the production hygiene the group must maintain every day. If the group holds documents or standards previously inspected by a government agency, it should check with that agency or with the local public health officer before producing and selling again.

10 Reasons Community Fermentation Sheds in In Buri Choose WHD

1. Straight talk about what to discard. The team never suggests disinfecting food and helps set a clear order for discarding and washing.
2. Droplets reach roof frames and wooden walls through our ULV disinfection service.
3. Reduces rotten odour soaked into wood with our ozone treatment service.
4. Helps reduce flies drawn by the smell. Once the odour source is gone, insects have less reason to come.
5. A clearly named product: CHEMGENE HLD4H.
6. Methods adapted to open-sided sheds. We assess the site before choosing the right approach.
7. Covers both the shed and the front stall in a single appointment.
8. Advice for the future, such as raising jars on platforms and planning how to move stock when water comes.
9. Add-on mosquito spraying if water is still standing around the house.
10. Helps the group tell customers with confidence how old stock was discarded and the shed restored.

Before and After: Restoring a Pla Ra Fermentation Shed

A Group Leader's Voice (Example Scenario)

"Pouring out the first jar really hurt. We had been fermenting it since the start of the year. But if we had kept it and someone got sick, our group would have lost far more. Once everything was thrown out and washed, the team came to fog and run the ozone. The rotten smell in the wood faded a lot, and there were fewer flies. We have started a new batch now, and we tell customers honestly that this lot was made after the water went down."

— Leader of a women's pla ra group, In Buri (example scenario)

Frequently Asked Questions

Q: The jar lid is still tightly tied, but water reached halfway up. Can I keep it?
A: You should not. Water can seep past the rim, the cloth cover or tiny cracks. The safe course is to discard every jar of fermented food that the water reached.

Q: Will ozone treatment make the remaining pla ra safe?
A: No. Fogging and ozone are carried out only in the empty shed, never on food. All food must be removed first.

Q: Can washed earthenware jars be reused?
A: Jars without cracks that have been washed several times and dried completely in the sun can be considered for reuse. Cracked or absorbent jars should be thrown away.

Q: Our shed is open-sided. Can it still be ozone-treated?
A: The team will assess the site. If the space can be temporarily enclosed, ozone can be used. If it is very open, we focus on fogging and suggest other measures alongside.

Q: Will ozone treatment before fermenting affect the flavour of the next batch?
A: Treatment happens before the new batch starts and is followed by ventilation, so it does not act on pla ra fermented afterwards. The aim is to reduce the rotten odour and mold left by the flood.

Q: Should our house be treated too?
A: If the house was also flooded, it is best to treat both together. See more about residential ozone disinfection.

Q: Where should we dispose of large amounts of pla ra?
A: Ask your municipality or subdistrict administrative organisation about suitable organic-waste disposal points. Never pour it into waterways.

Preparing the Shed for the Next Flood Season

• Build concrete plinths or steel racks that hold jars above the highest flood level you have seen.
• Split pla ra into smaller containers so they can be carried to safety quickly.
• Keep a simple log of when each jar was started, so decisions about damaged stock are easier.
• Keep tarpaulins and rope close at hand during the rainy season.
• Check the roof and gutters so rainwater does not drip onto the jars.
• Agree in advance which members will help move stock if a flood warning is issued, and where it will be taken.

Planning ahead turns a disaster into a manageable setback. Groups that raised their jars after one flood often find they lose far less the next time the river rises, and they can restart production within days rather than weeks.

Talking to Customers About the New Batch

Community producers sometimes worry that admitting their shed was flooded will scare customers away. In practice, honesty usually builds trust. A simple notice at the stall, or a short message in the village LINE group, explaining that all flooded stock was discarded, the shed was cleaned, disinfected and ozone-treated, and the new batch was started afterwards, tells customers exactly what they want to know.

It also helps to be clear about timing. Pla ra needs time to ferment, so there may be a gap before the new batch is ready. Some groups use that time to sell other products made fresh after the flood, such as chilli pastes prepared in a cleaned kitchen with new ingredients, so that customers keep coming back to the stall while the main product matures.

What the Day of Treatment Looks Like

Many group members have never seen a professional disinfection visit, so it helps to know what to expect. On the agreed day, the team arrives and first walks through the shed with the group leader to confirm that every jar, drum, bag of salt and piece of equipment has been moved out. If anything food-related is still inside, it is carried out before work begins.

Next comes fogging. Team members wear protective gear and move steadily through the shed, directing the fine mist of disinfectant at the roof frame, walls, racks, floor and corners. Members are asked to wait outside at a comfortable distance. When fogging is finished, the ozone generator is placed in position, openings are closed off as far as the structure allows, and the shed is left sealed for the treatment period. Clear signs are placed at the entrances so that neighbours, children and animals stay away.

After treatment, the team opens everything up and lets air flow through until the ozone has broken down. Only then does the group go back in to inspect. The team points out any remaining damp patches, explains how to keep the shed dry over the coming weeks, and answers questions about when and how to start the next batch. The whole process is designed to be calm, safe and easy for a community group to follow.

Start the New Batch in a Clean Shed Without Lingering Rot

Talk to the WHD team about disinfection fogging and ozone treatment for pla ra fermentation sheds, pla som workshops and community fermented-food shops in In Buri and nearby areas of Sing Buri province.

View Disinfection Service – Click Here

Book Ozone Treatment – Click Here

Call 065-556-6294 · LINE @whd268 · Email worldhealthdisinfection@gmail.com

Related Links

• Ozone odour and chemical residue removal
• Master Ozone Generator
• Mosquito spraying service
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Health references: World Health Organization (WHO): Floods · Department of Disease Control, Thailand