ACV Vinaigrette — Emulsion Chemistry in a Jar
Why apple cider vinegar makes a more stable dressing than white vinegar.
Chad Waldman
Analytical Chemist · April 19, 2026
Prep
5 min
Ferment
None
Total
5 min
pH Target
3.0–3.5
Salt
To taste
Difficulty
Beginner
I make my own vinegar. I make my own dressing. The two are related.
When you ferment apple cider into vinegar, you carry over more than acetic acid. You get malic acid from the apples, citric acid from fermentation byproducts, and residual apple pectin — a polysaccharide that acts as a natural emulsifier. Distilled white vinegar has none of this. It's pure acetic acid and water. That's why white vinegar dressings are harsher and break faster.
The polyphenol content of ACV is real, though modest. A 2020 study (PMID: 33202797) in Antioxidants (Basel)analyzed fermented apple peel vinegar and found measurable concentrations of chlorogenic acid, epicatechin, and quercetin derivatives — all carried through from the apple source material. You're not drinking a supplement, but you're not dressing your salad with nothing either.
Emulsion stability is the more interesting chemistry. A 2025 study (PMID: 39942797) in Molecules examined how vinegar concentration affects physical stability of oil-in-water emulsions in salad dressings, finding that acidic pH interacts with emulsifier proteins at the oil-water interface to affect droplet size distribution and overall emulsion longevity. The takeaway: the acid is not a passive bystander. It changes the chemistry of emulsification.
And if you needed a practical reason to dress your salad rather than eat dry greens: vinegar directly reduces pathogen load on leafy vegetables. A 2012 Journal of Food Protection study (PMID: 22828283) found that vinegar combined with oil as a salad dressing reduced Salmonella enterica on spinach leaves by up to 2.0 log CFU after 20 minutes at room temperature. Your dressing is doing safety work.
This takes 5 minutes.You'll never buy bottled dressing again.
Ingredients
- 1/4 cup apple cider vinegar — raw, unfiltered — with the mother
- 3/4 cup extra virgin olive oil — cold-pressed EVOO
- 1 tbsp Dijon mustard — the emulsifier — don't skip
- 1 tsp raw honey — balances acid; sub maple syrup for vegan
- 1 clove garlic — minced fine
- salt — to taste
- black pepper — freshly cracked
Equipment: wide-mouth mason jar with lid, whisk (or just shake the jar — both work).
Instructions
1Combine the acid and emulsifiers
Add the ACV, Dijon mustard, raw honey, and minced garlic to a wide-mouth mason jar. The mustard is doing real work here — its mucilage contains long-chain polysaccharides that act as a surfactant, reducing surface tension at the oil-water interface. Without it, your dressing breaks within 30 seconds. With it, you get 10–15 minutes of stable emulsion before a gentle reshake is needed.
Chemist's note
Use raw, unfiltered ACV with the mother. The mother is a cellulose mat of acetobacter — it contains additional surface-active proteins that contribute minor emulsification. Filtered ACV loses this.
2Add the oil slowly
Pour the olive oil in while whisking constantly — or, if using the jar method, add the oil in three additions, sealing and shaking vigorously between each. The slow addition creates smaller oil droplets dispersed in the aqueous phase. Smaller droplets = more surface area = more Dijon molecules at the interface = more stable emulsion. Dumping all the oil at once creates large droplets that coalesce fast.
Chemist's note
Extra virgin olive oil is not just a flavor choice. EVOO contains natural emulsifiers — phospholipids, sterols, and polar phenols — that sit at the oil-water interface and provide minor stabilization beyond the mustard. Refined oils don't have this.
3Season and taste
Add salt and several cracks of black pepper. Taste. The ratio is 3:1 oil to ACV — that's the classic vinaigrette proportion, and it's not arbitrary. At 3:1, the acidity is present and sharp without being harsh. At 2:1, it's too tart for most greens. At 4:1, you lose the acid brightness that makes vinaigrette worth eating. Adjust with a few drops more ACV or honey as needed.
Chemist's note
ACV has a pH of roughly 3.0–3.5, lower than most white wine vinegars (pH 3.4–3.7). The lower pH means brighter acid perception at the same volume. You may need slightly less ACV than you'd use with other vinegars.
4Store and use
Cap the jar and refrigerate. It keeps for up to 2 weeks. Cold temperature slows coalescence — the same droplets that would merge and separate at room temperature remain suspended longer in the fridge. Before each use, shake or whisk to re-emulsify. It takes 5 seconds. This is not a flaw. Every oil-and-acid dressing breaks over time. The difference is whether it re-emulsifies easily — and this one does.
Chemist's note
The garlic will mellow considerably after 48 hours as it infuses into the oil. If you want sharp raw-garlic heat, use the dressing within 24 hours. For a rounder, more integrated flavor, give it a day or two in the fridge first.
Variations
The base formula is 3:1 oil to acid + Dijon + sweetener + garlic. Swap components to suit the dish.
Lemon Herb
Replace half the ACV with fresh lemon juice. Add 1 tbsp each fresh parsley and chives, minced. Bright and green — pairs with fish and grain bowls.
Asian Sesame
Swap ACV for rice vinegar, EVOO for sesame oil (use 1/4 cup sesame + 1/2 cup neutral oil). Add 1 tsp soy sauce, 1 tsp grated ginger. Finish with toasted sesame seeds.
Maple Balsamic
Replace ACV with balsamic vinegar (aged if you have it). Replace honey with maple syrup. Add 1/2 tsp fresh thyme. Rich and sweet — designed for roasted vegetables.
Italian Herb
Keep the ACV base. Add 1/2 tsp dried oregano, 1/2 tsp dried basil, pinch of red pepper flakes. Skip the honey. This is the vinaigrette for a chopped salad or caprese.
Why ACV and not white vinegar
Distilled white vinegar is acetic acid diluted to 5% in water. That's the whole story. It's a useful acid for cleaning, pickling, and cleaning coffee makers. As a dressing base, it's functional but harsh — one-dimensional acid with no complexity.
Apple cider vinegar inherits chemistry from two fermentation stages. First, yeast converts apple sugars to alcohol; it leaves behind malic acid (the primary acid in apples, pH-softening relative to acetic), trace citric acid, and phenolic compounds. Then acetobacter converts the alcohol to acetic acid — and the non-volatile compounds remain. When you make vinegar from scratch, you see exactly what carries through.
The result is an acid with a lower perceived harshness at equivalent pH. Malic acid has a softer, rounder sourness than pure acetic. The residual pectin from apple cell walls contributes surface-active behavior. The polyphenols add minor antioxidant capacity. None of this is dramatic — ACV is not a health supplement — but in aggregate it explains why ACV dressings taste better and hold together longer than white vinegar dressings at identical oil-to-acid ratios.
The Dijon is still the primary emulsifier. ACV is the better acid base. EVOO provides its own polar lipid stabilizers. The honey adds a minor thickening effect via its high-molecular-weight sugars. This is a well-engineered dressing, whether you think about it that way or not.
Research cited
- PMID 33202797Antioxidants (Basel), 2020 — Polyphenol and antioxidant profile of fermented apple vinegar — chlorogenic acid, epicatechin, quercetin derivatives identified by HPLC.
- PMID 39942797Molecules, 2025 — Vinegar concentration and phenolic compounds affect emulsion stability and oxidation protection in oil-in-water salad dressing emulsions.
- PMID 22828283Journal of Food Protection, 2012 — Vinegar combined with oil as salad dressing reduced Salmonella enterica on spinach leaves by up to 2.0 log CFU within 20 minutes at room temperature.
Based on articles retrieved from PubMed (pubmed.ncbi.nlm.nih.gov).