How to Make Acetic Acid for Wound Care

Acetic acid for wound care is made by diluting ordinary white household vinegar, which is typically a 5% acetic acid solution, with clean water to reach the concentration your clinician has recommended. The most commonly studied clinical concentration is 1%, achieved by mixing one part white vinegar with four parts water. The preparation itself is simple, but the concentration you choose, the water you use, and how you apply the solution all matter for both safety and effectiveness.

Why Vinegar Works on Wounds in the First Place

Acetic acid has been used on infected wounds for a remarkably long time, predating modern antibiotics by centuries.1PubMed Central. Acetic acid dressings: Finding the Holy Grail for infected wound management It kills bacteria by lowering the pH of the wound environment to a level most microorganisms cannot tolerate. That acidic environment disrupts cell membranes and interferes with the energy production bacteria need to survive and multiply.

What makes acetic acid especially interesting for wound care is that it is effective against a wide range of bacteria. Lab testing shows strong antibacterial activity against both gram-positive and gram-negative species, with very low concentrations needed to inhibit organisms such as Klebsiella pneumoniae, Proteus vulgaris, Enterococcus species, and Serratia marcescens.2PubMed Central. Evaluation of the Antibacterial Activity of Acetic Acid in Comparison With Three Disinfectants Against Bacteria Isolated From Hospital High-Touch Surfaces It also destroys biofilms, the stubborn, slime-like colonies that bacteria form on wound surfaces and that make infections so difficult to clear with antibiotics alone.3PubMed Central. Antibiofilm Properties of Acetic Acid

Choosing the Right Concentration

Clinical studies and wound care protocols have used acetic acid at concentrations ranging from 0.25% all the way up to 2%. The concentration matters because a stronger solution kills bacteria faster but can also irritate the wound bed and harm the healthy cells you need for healing. Finding the balance between antimicrobial punch and tissue friendliness is the whole game.

Here is how the most-studied concentrations line up in practice:

If your clinician has not specified a concentration, 1% is the safest default backed by the most clinical evidence. It is strong enough to clear the infections most wound care practitioners worry about, while causing minimal damage to the fibroblasts and keratinocytes your body needs to rebuild tissue.

How to Dilute White Vinegar Step by Step

Dermatologists and wound care nurses have long given patients instructions for making acetic acid solutions at home from grocery-store vinegar rather than purchasing medical-grade preparations.7Journal of the American Academy of Dermatology. Vinegar (acetic acid) as a treatment for hypergranulation tissue The key is knowing the starting concentration of your vinegar and doing the arithmetic correctly.

Standard white distilled vinegar sold in most grocery stores is labeled at 5% acetic acid. Some “cleaning vinegar” products are 6% or higher, and apple cider vinegar varies, so always read the label. Use plain white distilled vinegar, not flavored, herbal, or “cleaning” varieties that may contain additives you do not want in a wound.

To reach common wound-care concentrations from standard 5% white vinegar:

  • 1% solution: Mix one part vinegar with four parts water. For example, one tablespoon of vinegar plus four tablespoons of water gives you roughly five tablespoons of 1% acetic acid solution.
  • 0.5% solution: Mix one part vinegar with nine parts water.
  • 0.25% solution: Mix one part vinegar with nineteen parts water.
  • 2% solution: Mix two parts vinegar with three parts water.

Use the cleanest water available. Sterile water or distilled water is ideal. If you only have tap water, bring it to a rolling boil, let it cool to room temperature, and then mix. Introducing tap water with unknown bacterial content into an open wound defeats the purpose. Mix a fresh batch each day rather than storing it, since the solution can become contaminated sitting in a container.

Applying the Solution to a Wound

Clinical protocols generally call for saturating a piece of gauze in the acetic acid solution and laying it directly over the wound, then covering it with a dry outer dressing to hold everything in place. In the chronic leg wound cases treated with 0.25% acetic acid, patients applied moistened gauze twice daily and secured it with a compression stockinet.4PubMed. Acetic Acid Use in Chronic Wound Healing: A Multiple Case Series In the burn wound trial protocol, dressings were changed twice daily for the first two days, then reduced to once daily on the third day to test whether the acetic acid stayed active over longer contact periods.5BMJ Open. Efficacy and optimal dose of acetic acid to treat colonised burns wounds: protocol for a pilot randomised controlled trial

A practical approach for home use looks like this:

  • Clean the wound first. Gently rinse the wound with saline or clean water before applying the acetic acid dressing. The acid works on bacteria, not debris.
  • Saturate, don’t drip. Soak a clean gauze pad in your prepared solution so it is thoroughly wet but not dripping excessively.
  • Apply and cover. Place the wet gauze over the wound, then apply a dry secondary dressing on top to keep it in place and protect your clothing.
  • Change regularly. Twice a day is the frequency most often described in clinical practice. Leave the moist gauze in contact with the wound for the hours between changes.

Expect some stinging or mild burning when you first apply the dressing, especially with a 1% or 2% concentration. If the discomfort is severe or persists well beyond the first few minutes, the concentration may be too strong for your wound, and stepping down to 0.5% or 0.25% is a reasonable adjustment to discuss with your provider.

Safety and the Cytotoxicity Trade-Off

Topical antiseptics sit in a tension that has frustrated wound care practitioners for decades: the same properties that kill bacteria can also damage the healthy human cells responsible for wound healing. Acetic acid is no exception. Research on the cytotoxic effects of commonly used topical antimicrobials has shown that clinically relevant doses of many agents, including acetic acid at higher concentrations, can reduce the activity of fibroblasts and keratinocytes.8PubMed. The cytotoxic effects of commonly used topical antimicrobial agents on human fibroblasts and keratinocytes

The good news is that at the concentrations used for wound care, the damage appears manageable. A recent study directly comparing 1% acetic acid to povidone-iodine (Betadine) found that 1% acetic acid had negligible effects on fibroblast viability and actually supported fibroblast proliferation when used to soak dermal matrices, while Betadine was strongly cytotoxic.9Bratislava Medical Journal. 1% Acetic Acid as an Effective and Cytocompatible Antimicrobial Agent with Enhanced Activity in Acellular Dermal Matrix for Wound Management This suggests that at 1%, acetic acid strikes a favorable balance: potent enough to clear infection, gentle enough that your body’s repair machinery keeps working.

A few safety points deserve attention. Do not use acetic acid on deep puncture wounds, surgical wounds with exposed tendons or bone, or wounds where you can see deep tissue structures. Those wounds need professional assessment. Do not pour undiluted vinegar onto a wound. Five percent acetic acid straight from the bottle is substantially more concentrated than what clinical studies use, and it can cause tissue damage and intense pain. Always dilute first. And if you have any known sensitivity to vinegar or acetic acid, test a small amount on intact skin near the wound before applying it directly.

Why Acetic Acid Matters in an Era of Antibiotic Resistance

One of the strongest arguments for keeping acetic acid in the wound care toolkit has nothing to do with cost or convenience. It has to do with the growing crisis of antibiotic-resistant bacteria. Pseudomonas aeruginosa, which is one of the most common and stubborn wound pathogens, increasingly shows resistance to multiple classes of antibiotics. In the randomized trial comparing 1% acetic acid to saline, antibiotic-resistant Pseudomonas took an average of 15.5 days to clear with saline alone, versus about 4.5 days with acetic acid.6PubMed Central. Efficacy of 1% acetic acid in the treatment of chronic wounds infected with Pseudomonas aeruginosa: prospective randomised controlled clinical trial The acetic acid cleared resistant and susceptible strains in the same time frame, meaning resistance to antibiotics did not give the bacteria any advantage against the acid.

This finding makes acetic acid particularly valuable as an alternative when infection is caused by multidrug-resistant strains.10PubMed. Acetic acid treatment of pseudomonal wound infections–a review The mechanism of killing, disrupting the bacterial cell environment through pH change, is fundamentally different from how antibiotics work. Bacteria evolve resistance to antibiotics by developing specific molecular defenses against specific drug molecules. Evolving resistance to a broadly corrosive acid that dismantles cell membranes is a much harder trick for a microorganism to pull off. While no one claims resistance is impossible, it has not been observed as a practical problem with acetic acid in the way it has with, say, topical antibiotics like mupirocin.

What Acetic Acid Actually Clears From Wounds

While Pseudomonas aeruginosa gets most of the attention in the literature, acetic acid is not a one-target treatment. The study of 100 patients with infected wounds treated with 1% acetic acid isolated a range of organisms: Pseudomonas aeruginosa was present in about 40% of cases, Klebsiella in 18%, Acinetobacter in 12%, methicillin-resistant Staphylococcus aureus (MRSA) in 10%, Escherichia coli in 5%, Proteus mirabilis in 3%, Staphylococcus aureus in 2%, Streptococcus in 2%, Enterococcus in 1%, and Citrobacter in 1%. Across all of these organisms, 1% acetic acid dressings eliminated bacterial growth in roughly 28% of patients within seven days and in 64% by fourteen days.1PubMed Central. Acetic acid dressings: Finding the Holy Grail for infected wound management

The breadth of that activity is striking. This is not a narrow-spectrum treatment aimed at one species. The low minimum inhibitory concentrations recorded in laboratory testing, some as low as 0.05 μL/mL, suggest that even the gentler dilutions used clinically have enough antimicrobial punch to deal with many of the organisms that colonize chronic wounds.2PubMed Central. Evaluation of the Antibacterial Activity of Acetic Acid in Comparison With Three Disinfectants Against Bacteria Isolated From Hospital High-Touch Surfaces

Common Mistakes When Preparing Acetic Acid at Home

The simplicity of the preparation can breed overconfidence. A few recurring mistakes are worth flagging because they can turn a helpful remedy into a harmful one.

The first and most common mistake is skipping the dilution. People read that “vinegar kills bacteria” and apply it at full grocery-store strength. At 5%, you are using a concentration five times higher than the most commonly studied clinical dose and twenty times higher than the gentlest clinical concentration. The stinging will be severe, and the risk of tissue damage goes up substantially.

The second mistake is using the wrong vinegar. Apple cider vinegar, balsamic vinegar, rice vinegar, and wine vinegar all contain acetic acid, but they also contain sugars, pigments, proteins, and other organic compounds. These extras can feed bacteria, stain wound beds, or introduce allergens. White distilled vinegar is the only type appropriate for wound care because it is essentially just acetic acid and water.

The third mistake is reusing the solution. Mixing a large batch and storing it in a jar on the bathroom counter for a week invites contamination. Bacteria can colonize the container itself. Make a small fresh batch before each dressing change. It takes thirty seconds and costs almost nothing.

Finally, some people assume that if their wound is not improving, they should increase the concentration. The evidence does not support this approach. If a wound is not responding to 1% acetic acid within a couple of weeks, the problem is likely deeper than surface bacteria, and you need professional wound assessment rather than a stronger vinegar soak.

When Acetic Acid Is Not the Right Choice

Acetic acid dressings work best for chronic or slow-healing wounds that are colonized or mildly infected with bacteria, particularly when those bacteria have proven resistant to antibiotics. The classic scenario is a chronic leg ulcer, a pressure injury, or a burn wound with a greenish discharge and a sweet, distinctive odor that suggests Pseudomonas colonization.

Acetic acid is not a substitute for systemic antibiotics when you have signs of spreading infection: expanding redness around the wound, red streaks tracking up a limb, fever, increasing warmth, or rapidly worsening pain. Those signs suggest the bacteria have moved beyond the wound surface into deeper tissue or the bloodstream, and topical treatment alone will not be enough. Acetic acid works on what it touches. It cannot chase bacteria through your circulatory system.

It is also not ideal for clean surgical wounds that are healing normally. Those wounds benefit from a moist, undisturbed environment, and applying an antiseptic of any kind introduces unnecessary chemical insult to tissue that is already doing its job. Reserve acetic acid for wounds that are stuck, infected, or not responding to standard wound care.

Acetic Acid for Hypergranulation Tissue

Beyond infection control, wound care providers sometimes use vinegar solutions for a different problem entirely: hypergranulation tissue. This is the beefy, raised, overgrown tissue that sometimes develops in wounds and around feeding tubes, tracheostomy sites, and other chronic openings. The tissue bleeds easily, prevents wound edges from closing, and can become a persistent nuisance.

Dermatologists have used dilute vinegar applied to hypergranulation tissue to reduce the overgrowth and allow normal healing to resume.7Journal of the American Academy of Dermatology. Vinegar (acetic acid) as a treatment for hypergranulation tissue The mechanism here is somewhat different from its use against infection. The acidic environment appears to discourage the excessive cell growth while still allowing healthy tissue to heal underneath. Patients in these cases are typically given home instructions for making the solution themselves, reinforcing that this is considered a low-risk, accessible treatment when used at the correct dilution.

If you are dealing with a wound that seems to keep growing proud, bumpy tissue that rises above the level of the surrounding skin and will not flatten out, a short course of vinegar soaks may be worth discussing with your wound care provider before resorting to silver nitrate cautery or surgical excision.

Written by

Hugh Hawkins

Hugh Hawkins is an HCPC-registered paramedic in England with nine years on frontline ambulance crews. He earned his BSc in paramedic science at the University of Hertfordshire. As a clinical educator, he now teaches prehospital care and drug administration to student paramedics.