How to Make Vinegar from Scratch
The complete acetobacter story. A chemist's guide to homemade vinegar — apple cider, white, wine, and fruit vinegars.
Chad Waldman
Analytical Chemist · April 15, 2026
Prep
15 min
Ferment
3–8 weeks
pH Target
2.4–3.0
Difficulty
Intermediate
Yield
~1 quart
Vinegar is the only ferment on this site that needs oxygen. Everything else I make — sauerkraut, garlic, pickles — is anaerobic. Lactobacillus hates oxygen. But acetobacter, the bacterium that makes vinegar, requires it. Cover with cheesecloth, not an airlock. This is the one time I tell you to leave the jar open.
Most vinegar guides treat it like a recipe when it's actually a two-stage chemical conversion. Stage one: yeast converts sugar into ethanol. Stage two: acetobacter converts ethanol into acetic acid. You can skip stage one by starting with wine, cider, or beer that already has 5–10% alcohol.
I skip stage one. Life's too short to make alcohol just to turn it into vinegar. Buy a $5 bottle of wine and let the bacteria do the rest.
How is vinegar made? The chemistry.
The chemistry is straightforward. Acetobacter aceti oxidizes ethanol into acetic acid and water. The reaction requires molecular oxygen — that's why the cheesecloth matters.
Ethanol + O2 → Acetic Acid + Water
This is an exothermic oxidation. The bacteria sit in a biofilm (the “mother”) at the air-liquid interface where they have maximum access to both the alcohol below and the oxygen above. Disturbing the mother disrupts this interface and slows the process.
Conversion rate depends on temperature, surface area, and alcohol concentration. At 75–80°F with a wide-mouth container, expect 3–4 weeks. At 65°F in a narrow-neck bottle, 6–8 weeks.
Use our Vinegar Mother Calculator to estimate your conversion timeline based on your specific conditions.
Types of homemade vinegar
Apple Cider Vinegar
Source: Hard cider or apple juice + yeast
Time: 4–6 weeks
Most popular. Fruity, mild, versatile.
White Wine Vinegar
Source: Dry white wine (dilute to 7%)
Time: 6–8 weeks
Higher alcohol = slower. Rich flavor.
Red Wine Vinegar
Source: Dry red wine
Time: 6–8 weeks
Complex. Great for dressings.
Pineapple Vinegar
Source: Pineapple scraps + sugar + water
Time: 3–4 weeks
Two-stage ferment. Zero waste.
Ingredients
- 1 bottle (750mL) wine, hard cider, or beer (5–10% ABV)
- 1/4 cup raw unpasteurized vinegar (or a vinegar mother)
- 1 wide-mouth glass jar (quart+)
- 1 cheesecloth + rubber band
Equipment: pH meter for testing. Use our Vinegar Calculator for timing.
Instructions
1Start with alcohol
Vinegar is a two-stage fermentation. First, yeast converts sugar to alcohol. Then acetobacter converts alcohol to acetic acid. You can skip stage one by starting with wine, cider, or beer.
Chemist's note
Any alcohol between 5–10% works. Higher alcohol takes longer. Hard cider and cheap wine are the easiest starting points.
2Add a mother (or wait)
A vinegar mother is a cellulose mat of acetobacter bacteria. If you have one, add it. If not, add a splash of raw unpasteurized vinegar and the bacteria will colonize on their own.
Chemist's note
Unlike lacto-fermentation, vinegar NEEDS oxygen. Acetobacter is aerobic. Cover with cheesecloth, not an airlock.
3Cover with cheesecloth and wait
Place in a warm, dark spot (70–85°F). Cover with cheesecloth — acetobacter needs air but you want to keep flies out. Conversion takes 3–8 weeks.
Chemist's note
Don’t stir. Don’t disturb the mother forming on the surface. It’s a biofilm doing the work.
4Test pH and taste
Start testing after 2 weeks. pH should drop below 3.5. When it’s sour with no alcohol flavor, it’s done. Typical vinegar: pH 2.4–3.0, 4–7% acidity.
Chemist's note
Use your pH meter. For exact acidity percentage, you need a titration kit. For home use, pH below 3.0 and strong sour taste means done.
5Bottle and store
Strain the mother (save for next batch). Pasteurize at 140°F for 10 min to stop fermentation, or bottle raw with live bacteria.
Chemist's note
Raw vinegar is alive. Pasteurized is shelf-stable. I keep mine raw because the mother is useful for the next batch.
How to make white vinegar at home
White vinegar is acetic acid diluted in water. Commercial versions start with grain alcohol converted industrially, then diluted to 5% acidity.
At home, use vodka or grain alcohol diluted to 7–8% ABV. The result has subtle character from the acetobacter but works for cooking, cleaning, and pickling.
For most home cooks, apple cider or wine vinegar is better. The flavor is superior and the process is identical.
Troubleshooting
No mother forming after 2 weeks
Too cold or not enough oxygen. Move warmer. Check cheesecloth airflow. Add more raw vinegar.
Fruit flies getting in
Use finer cheesecloth or coffee filter. Fruit flies love acetic acid.
Smells like nail polish remover
That's ethyl acetate, not acetic acid. Too much oxygen too fast. May resolve in 2 weeks.
Still not sour after 8 weeks
Test pH. If not dropping: too cold, too little oxygen, alcohol too high, or chlorinated water.
More issues? Try our Fermentation Troubleshooter.
The science
Acetic acid is antimicrobial. Homemade vinegar at 4–7% acidity is comparable to store-bought for preservation.
A 2024 study (PMID: 38717160) confirmed pH below 4.4 eliminates pathogen survival. Vinegar typically reaches pH 2.4–3.0 — well below this threshold.
A 2021 study in Cell (PMID: 34256014) showed a diet high in fermented foods increased gut microbiota diversity and reduced 19 inflammatory markers. Raw vinegar contains live acetobacter and contributes to this effect.
Read all research on our Science page.