Apple Cider Vinegar | Masterclass (FREE)

Vinegar so good you can drink it

No, I’m not crazy. Vinegar, when made with a considered, delicate approach, can exceed even a refreshing, sparkling kombucha. I regularly ferment most of the alcohol I make into vinegar for both drinking and cooking, to the dismay of my friends, and apple cider vinegar is one of my favourites for this. In this newsletter, I will cover how you can turn hard cider into vinegar, make a delicious herbal drinking vinegar, and a brief bit on how we ended up where we are in terms of vinegar and its uses, and what we might learn from understanding its history.

Topics:

A Gift From a Bodega
The Art, Science, and History of Vinegar
A Splash in the World’s Vinegar
Alchemy | turning any fruit juice into artisanal vinegar
Apple Cider Vinegar (recipe)
Tips and Troubleshooting
Herbal Drinking Vinegar (recipe)
A Spooky Ending

A vinegar better than cider

---

A Gift From a Bodega

As a chef, I’ve always loved vinegar. From quick pickles and preserves to a lip smacking tang in sauces, stews, and dressings. Vinegar, that comes in as many varieties as fruits and alcohols do, has an innate versatility in the kitchen, from the mellow oak notes of malt vinegar on your fish and chips to the dark figgy molasses of balsamic.

My eyes were truly opened to the possibilities of vinegar when I met an owner of a bodega (a Spanish wine producer). For the sake of anonymity, I won’t name the bodega itself, and we’ll call the owner Isabella (which is not far from her real name). At the time I was working for a Spanish tapas restaurant with a significant wine selection, who regularly organised meetings, training, and wine tasting with their suppliers. Isabella, who had inherited the bodega she grew up on from her late father, was a graceful, relaxed woman in her mid 40s, with a deep and sincere kindness that seemed to emanate from her, possibly instilled within her from a life of sunshine and grape vines. 

Despite her aim, to teach us about the wine she produced, she first offered a wholly different bottle of dark, syrupy liquid. A vinegar, also produced on her estate. Smiling at our confusion, she explained that it was a tradition from her father, who would greet all those who visited their bodega with a small bottle of the very same vinegar. Now, her father’s aim was to point out that if the vinegar they produced was this good, the wine was going to be unbelievable. But for me, this small, unassuming bottle had blown the lid off what I thought was even possible for vinegar to be. Sweet, complex, lively, full of rich fruity flavour with hints of oak, vanilla, and cherry, and a crisp, dry velvety finish. It rivalled the best wines or coffees I’d tried, at once punchy, but equally subtle and mellow. I fell in love.

I grew more and more obsessed with making my own vinegar, including vinegars you don’t normally find in any stores. A bottle of mango juice? Organic pressed carrot juice? Spicy raspberry mead? Even whisky. One way or another, they all found themselves happily fermenting into vinegar, each with a jellyfish-like blob of cellulose floating around in them. What was intended as a nod to her father's cheeky flex to visitors had the effect of lighting a fire of curiosity in me. One that I now hope to pass on to you.

---

The Art, Science, and History of Vinegar

Vinegar, whose very name stems from the Old French “vinaigre” or “sour wine”, has been a staple in kitchens and medicine cabinets alike since the earliest recorded human history. Its uses include food preservation, a digestive aid, tonic, and cleaning agent dating back as far as 3000 BCE. By the Middle Ages, European vinegar production had grown significantly, with the appearance of regional characteristics reflecting the flavours and diverse techniques of the area. France became famous for its wine-based vinegars, whilst Italy leaned heavily on balsamic from Modena, and the British Isles saw the emergence of malt and cider vinegar, each with its unique nuances of taste.

In the UK, vinegars were a culinary staple long before mass production took hold. In the countryside, farmers would produce small batches using traditional methods, and the art of home vinegar-making was often passed from one generation to the next. A tradition we’re taking part in at this very moment.

Science of Vinegar: Two Stage Fermentation

Making vinegar involves two processes, each handled by distinct groups of microorganisms. The first stage is alcoholic fermentation, carried out by yeasts, usually of the genus Saccharomyces. When these yeasts consume the sugars in fruit juice, they produce alcohol and carbon dioxide, which is what turns juices into wine, cider, and perry. The same is true for mead, whisky, and beer.

In the second stage, a group of bacteria known as Acetobacter initiates acetic acid fermentation, converting ethanol (alcohol) into acetic acid in the presence of oxygen. Meaning, the moment we allow wine, cider, or beer to breath, they will spontaneously become vinegar. But we can get more creative than that. 

If you’d like to learn more about the first stage, turning any sugary juice or liquid into alcohol, read my previous newsletter on cider to see how to calculate sugar to ethanol conversion and figure out how much alcohol is in the final product. For this newsletter, I’m going to assume you know how to accomplish this first stage and now have a bottle or two of alcoholic liquid that you’d like to turn into the best vinegar you’ve ever tasted.

The most important step for vinegar is ABV (alcohol by volume) of the liquid you want to convert into vinegar. If it’s too high, the acetic acid bacteria won’t be able to tolerate the conditions and very little will happen. The cut off for this is around 10% ABV. So if your wine has an ABV of 14%, or you wish to turn a spirit like whisky into vinegar, you’ll need to lower the alcohol content first.

This can be done by simply watering it down, but this will dilute the flavour as well. My favoured method is to burn off the alcohol. To do so, calculate how much wine or whisky you’d need to reserve (remember, the AAB (bacteria) needs some to feed off, so we can’t remove all of it) then add the rest to a pan. For spirits and high alcohol products, flambé it (which removes around 75% of the alcohol in an instant). For wine, bring it to a simmer and cook it in an open pan for 30 minutes. This will remove 90% of the alcohol. Once cooled down again, you can add the reserved wine back in and crack on with vinegar fermentation.

Associated Health Benefits 

The main health benefits of vinegar are linked with its main active component, acetic acid. Research suggests a link between consuming vinegar with or shortly before meals and more stabilised blood sugar levels. This is thanks to vinegar’s influence on enzymes in the digestive tract that break down starches, slowing down carbohydrate absorption. Something that might cross your mind the next time you’re dipping bread in a plate of olive oil and vinegar. 

In addition to this, some studies have shown promise in the role vinegar plays in cardiovascular health, lowering both triglycerides and LDL cholesterol. Whilst research is ongoing, these findings suggest that vinegar’s antioxidant compounds may also help reduce oxidative stress, benefiting heart health. Not to mention the usual benefits of fermented foods, namely probiotics and beneficial bacteria. If you’re partial to a kombucha for the probiotics, vinegar comes with many of the same benefits and tends to be cheaper, and easier to make at home.

---

Honey vinegar on the left, reduced cider vinegar on the right

A Splash in the World’s Vinegars

Types of Vinegar and Regional Variations

Each type of vinegar carries a unique flavour profile shaped by the base ingredients, the environment in which it was produced, and the population of wild yeasts and bacteria responsible for them. The sheer diversity is astonishing.

1. Apple Cider Vinegar: Known for its amber hue and fruity tang, apple cider vinegar is a cherished culinary ingredient and tonic in traditional health practices across the US and British Isles.

2. Malt Vinegar: A staple in British cuisine for centuries. Mellow, oaky, and malted, made from fermenting sugars in malted barley (germinated and dried), this vinegar is most associated with a classic fish and chips, but has found its way into dishes from all over the island.

3. Wine Vinegar: French wine vinegars are iconic and made in various regions across the country, from Champagne to Burgundy. Broadly available as red or white, they have distinct lively fruity notes and robust flavour, lending themselves well to sauces and dressings.

4. Balsamic Vinegar: Originating in Modena, Italy, balsamic vinegar goes through a long ageing process, developing its rich, syrupy consistency and complex, almost sweet flavour. Traditional balsamic vinegar is aged for over 25 years.

5. Rice Vinegar: Hailing from East Asia, rice vinegar is mild, sweet, and light, with a gentle acidity compared to other vinegars. Smooth and delicate, it can add brightness to dishes without overwhelming other flavours. 

6. White, Black, and Red Rice Vinegar: Within rice vinegar, there are three major categories of vinegar, each with different properties. White is light and subtle, black is darker and more complex (often used in Chinese cookery), and red is slightly sweet, often used in dipping sauces.

7. Honey Vinegar: Made from fermented honey (mead) and boasts bold floral notes and subtle sweetness. It is often used in dressings and health elixirs.

8. Herb and Fruit Vinegars: With infusions of herbs like tarragon, or fruits such as raspberry, these vinegars are lighter and lend a fresh, aromatic touch to salads, sauce, and dishes. They also lend themselves nicely to drinking vinegar.

9. Date Vinegar: Made from fermented dates and popular in Middle Eastern cooking, it is deep with fruity sweetness.

10. Palm Vinegar: Made from sap of the nipa palm or coconut and common in the Philippines. It is sweet and mellow with earthy undertones.

11. Cane Vinegar: Made from fermented sugarcane juice, also especially popular in the Philippines.

12. Beer Vinegar: Made from fermented beer, with a malty flavour and gentle bitterness. Mostly used in Belgium and Germany.

13. Yuzu Vinegar: A recent superstar in the culinary world, yuzu is a Japanese fruit that can make a punchy, citrusy, bitter vinegar that’s absolutely delicious.

Is there a particular vinegar you love to use? Or one that you think I’ve missed from my list? Let me know in the comments please!

---

Apple cider vinegar with cellulose mother

The Art of Making Apple Cider Vinegar

Homemade apple cider vinegar is complex, sweet, tangy, and transformative. If you believe as I do, that the best meals in life are homemade, then believe me, the same is true for vinegar. The tradition of apple cider vinegar here in Wales belongs to the home kitchen, and I am more than happy to share that with you so you too can take part in this practice, wherever you may be in the world.

If you want to crack on with this recipe but haven’t made your own homemade cider, you can buy a hard cider from the store instead, but make sure it’s a tasty one. If you wouldn’t happily drink it, it’ll likely make poor vinegar too. If you’d like to learn to make your own cider, now is the time! Apples harvest at this time of year here in Wales and the whole process of fruit to vinegar is a wonderful event to take part in. Learn how to make cider from apples or a fresh, organic apple juice by reading my previous article here.

Ingredients:

1 litre (1 quart) raw, unpasteurised apple cider (preferable organic)
2 tbsp (30ml) raw apple cider vinegar with ‘the mother’ (optional)
A glass jar
Cheesecloth, tea towel, or paper towel
String or an elastic band

Instructions:

Step 1: Set Up the Fermentation Vessel

1. Pour the apple cider* into a clean, wide-mouthed glass jar. This process can be done in a lunch box or any other container, but I’d advise using glass as the acidity of the vinegar can leach chemicals from plastic containers. You will also want a wide-mouthed container as the cellulose raft produced by the microbes will likely block a narrow jar or bottle.

2. If you have raw apple cider vinegar with ‘the mother’ (a cloudy, wispy bacterial substance that gathers in the bottom of the bottle containing beneficial bacteria), add 2 tbsp of it to the cider. This addition can help inoculate and accelerate fermentation by kick starting the process and lowering the pH upfront, helping prevent spoilage. However, you can skip this step if you don’t have any.

* Note, this is an alcoholic hard apple cider. In the UK, we just call the non-alcoholic drink “apple juice”.

Step 2: Initial Alcoholic Fermentation

1. Cover the jar with cheesecloth and secure it with an elastic band. This allows oxygen to circulate whilst keeping out dust and fruit flies.

2. Place the jar in a warmish, dark location, such as a cupboard, for 3-4 weeks. Aim for a temperature of around 18–24°C (65–75°F). During this time, Acetobacter bacteria will start converting the alcohol into acetic acid, creating vinegar. Not only will you be able to smell this clearly, but you will also notice new layers of cellulose forming as gelatinous, cloudy biofilm on the surface of the liquid. Unlike kombucha scoby, which remain floating, vinegar mothers will sink in time or if disturbed. This is a natural byproduct of acetic acid bacteria and is a good sign that fermentation is active.

3. The conversion from alcohol to acid is: Acidity = ABV x0.8

   Example: If a cider has an alcohol content of 7%ABV, multiply this by 0.8 = 5.6% acidity. 5.6% acidity will display between 2.5-3 pH, depending on temperature.

4. Start tasting the vinegar after about 3 weeks. If it has reached a decent tangy, acidic flavour that you like, you can bottle it right away. If you’d prefer a stronger vinegar, leave it for another few weeks. You can leave it for as long as 6 months, where it will fully mature and begin to reduce, creating a clear, acidic, concentrated vinegar that’s almost a cheat apple balsamic vinegar (minus the flavours inherited from the oak barrel).

Step 3: Bottling and Storing

1. Once the vinegar is to your liking, strain it to remove the mother (which you can store with a small amount of unpasteurised liquid, in an airtight container in a fridge, or in a breathable container at room temperature, to inoculate future batches). Transfer the filtered vinegar into a sterilised glass bottle and seal it tightly.

2. Store the vinegar in a cool, dark place. You can use it right away, but it will continue to age and develop more complex notes over time as the acid and enzymes leftover from microbial activity continue to float around and unlock flavour.

A finished, aged homemade vinegar (bottled)

Tips and Troubleshooting: 

Patience is key, it can take vinegar 6+ weeks to fully mature depending on room temperature and the health of the bacterial culture you use. If you don’t inoculate the cider with a raw vinegar, it will take even longer to spontaneously occur, so be patient. 

If you store the mother in the fridge between batches, it may take a while to recover and restore full function in a fresh batch.

If you aren’t sure, trust your nose. Vinegar should smell fruity and tangy. If it smells rotten or off, discard it. This has never happened to me in all my years making vinegar, but it has to be said. Don’t take any risks. 

Sometimes, a vinegar mother (the cellulose raft that forms) can remain lodged at the top of the jar and dry out. If this happens, there’s a chance mould could grow on the surface and ruin the vinegar. If you notice a mother forming that hasn’t dropped after a week or so, use a clean spoon to push it down.

---

For additional infusions, use frozen fruit and berries of the season

Drinking Vinegar Recipe

On one of my many visits to London (usually to see my publisher), I visited a trendy little restaurant that had recently gained a permanent spot where it once ran as a pop-up. Besides the food, which was refreshingly seasonal and made in house (a rarity these days), it was the first menu I’d seen that suggested a pairing of drinking vinegar. My curiosity was piqued.

I ordered the drink and what arrived became the highlight of my meal.

At face value, it was essentially a vinegar cordial in sparkling water. What that description lacks is the refreshing clarity the drink offered. Without the sweetness of a cordial, the vinegar was diluted enough to be pleasantly acidic, like a grape or orange, but with the complexity of wine, only more subtle. The carbonation of the water elevated the aromatic qualities of the vinegar, which was infused with a small sprig of rosemary in the glass, complementing the savoury courses of my meal with an additional layer of fragrance and palate cleanser.

I got home a few days later, and went straight to my collection of homemade vinegars. Here’s what I found worked nicely.

Ingredients:

20ml homemade vinegar (any type works, fruity or malted)
150ml sparkling water
A sprig of rosemary or thyme
Ice / frozen fruit or berries
Honey (optional)

Instructions:

1. Make sure to refrigerate the water ahead of time.

2. Add the ice to the glass, however much you like.

3. Pour the water into a glass, then add the vinegar and herb. Allow the carbonation to mix the liquids, no need to stir.

4. Sweeten to taste with honey.

Note: I’ve also made winter versions of this with mulled cider spices and vinegar with more honey and dried apple rings. You end up with a lovely warming drink that feels like it’s doing you good in the cold months. It certainly clears a sore throat, especially if you add a drop of whisky. The apple rings act like a healthy, chewy, marshmallow.

---

A Spooky Ending

Happy Halloween and Samhain

As it’s Halloween and Samhain this week, I’d be remiss if I didn’t include a bit of a spooky vinegar tale that might just keep you safe from the witchcraft of mediaeval times (though I doubt it’s effect against the trick-or-treaters of today). Halloween originated from pagan roots when the early Catholic church Christianized the Celtic New Year festival and mixed Celtic traditions with Catholic saints. During Samhain, which marked the end of summer and harvests, it was believed the veil between the realms of the living and dead were opened. To protect themselves, Celts performed rituals such as lighting bonfires, wearing costumes, and carving grotesque faces into turnips, potatoes, beetroot, and mangelwurzels (sound familiar?). The latter is speculated to have evolved from the Northern territories Celtic custom of taking the severed heads of one’s enemies as a war trophy.

If head veneration doesn’t sound like your cup of tea, how about using some of your homemade vinegar to make a ‘witch bottle’? These glass or stoneware vessels were filled with sharp objects like nails and topped up with vinegar. Symbolic of vinegar’s acidic defence against malicious forces, with uses that included disinfecting wounds, soothing sore throats, relief for aching muscles, and even drawing out fevers, these ‘witch bottles’ were believed to protect against witchcraft and were buried near the doorways of houses to counter curses and hexes.

So, if you’re troubled by the thinning veil this Samhain, crack out a bottle of vinegar. Though, I might suggest using something cheap from the store. I doubt a curse will know the difference.

---

Thank you for joining me for another nerdy ramble into the niche world of fermentation. I hope you have a wonderful week, and remember to subscribe for many more ways to make delicious food and stave off hexes.