Beverage fermentation is an ancient ritual that has been practised for millennia. It was slowly disappearing from households and communities due to the advancement of manufacturing technology and the marketing of soft drinks until the recent revival of the beverage fermentation culture due to an increase in the demand for health drinks amid the COVID-19 pandemic. Imagine heading to the supermarket, eager to pick up apple cider vinegar, only to find an empty shelf where it should be. A quick glance upward reveals a whole rack filled with bottles of kombucha. It catches your eye with that familiar amber hue and slightly cloudy appearance. The puzzling resemblance between kombucha and apple cider vinegar is quite common, making you wonder whether they can be interchanged. However, despite the visual similarities, both have distinct characteristics that make them unique. This article will guide you through these two tangy beverages, their similarities, and key differences, helping you make the right choice.
Introduction
Kombucha and kefir are two well-known fermented beverages that are renowned for their myriad of health benefits. The starter materials for making these beverages contain micro-organisms that act like microscopic factories producing beneficial nutrients that have antimicrobial and anticancer effects. The materials modulate the gut microbiota and promote positive effects on the gastrointestinal tract. Fermented beverages have a long history of being enjoyed by diverse cultures worldwide, offering a wide variety of options ranging from boza [1], cider [1], and kvass [2] to mead [3] and sake [4]. Kombucha and kefir are notable additions to this category, contributing to the rich tapestry of fermented beverages that are cherished by people across the globe. Both these cultured drinks have been derived from ancient rituals and passed down since the dawn of time by people of many different cultures and backgrounds. Long notable in the East, kombucha has been consumed for over 2000 years and is said to have travelled to Europe and the rest of the world via trade paths [7,8]. Like kombucha, kefir has been around for umpteen years, dating back to the early people of the Caucasus Mountains [9]. Kefir grains were passed down from generation to generation among Caucasus tribes and were considered as a source of family wealth [9,10]. Around 1960s, kefir made its way to the western world [10]. The two ancient fermented beverages became popular as they possess characteristics of ‘functional food’.
What is Kombucha?
Kombucha is a probiotic-rich fermented tea beverage with a tangy flavour and slightly carbonated texture. This delicious drink is made by fermenting sweet black or green tea with the help of a culture known as SCOBY (Symbiotic Culture of Bacteria and Yeast) and starter tea. The SCOBY, which resembles a rubbery, slippery pancake, floats atop the tea and kickstarts the fermentation process. The fermentation process endows kombucha with probiotics and other essential nutrients, making it a healthy choice.
Potential Health Benefits of Kombucha
If you thought kombucha was just another cool drink on the aisle, you're in for a surprise. Though it's primarily known for its unique taste, kombucha is lauded for several potential health benefits.
- Probiotics: Kombucha contains several live bacteria and yeasts that can act as probiotics. These beneficial microorganisms contribute to a healthy gut microbiome, which plays a vital role in digestion, nutrient absorption, and immune function.
- Antioxidants: The tea used in kombucha (especially green tea) is a natural source of antioxidants, such as polyphenols. Antioxidants help neutralise free radicals that can damage cells and contribute to chronic diseases.
- Alternative to sugary drinks: Kombucha offers a low-calorie, less sugary alternative to sugary sodas and juices, which are often high in calories and contribute to weight gain and other health problems.
However, kombucha isn't everyone's cup of tea. Due to its natural fermentation process, it contains small amounts of alcohol (less than 0.5%), which may not be suitable for pregnant or breastfeeding women. Some might also experience digestive discomfort if they consume kombucha in large quantities or on an empty stomach.
Read also: Side Effects of Keto Apple Cider Vinegar Gummies
What is Apple Cider Vinegar?
Apple cider vinegar (ACV) is a fermented apple juice with a distinct sour taste and vinegary smell. It's a popular health tonic and culinary ingredient known for its potential health benefits. First, apples are crushed or pressed, and the juice is extracted. In the second step, bacteria, specifically Acetobacter species, convert the alcohol into acetic acid, the main component of vinegar.
Potential Health Benefits of Apple Cider Vinegar
- Digestive aid: The acidic nature of ACV may help improve digestion by increasing stomach acid production.
- Weight management support: ACV may contribute to weight management by promoting feelings of fullness and potentially reducing calorie intake.
- Blood sugar regulation: Some studies suggest that ACV may improve insulin sensitivity and help regulate blood sugar levels, particularly after meals.
However, moderation is crucial due to its acidity. Consuming undiluted apple cider vinegar can erode tooth enamel.
Similarities Between Kombucha and Apple Cider Vinegar
Do you want a simple hack to manage diabetes? Kombucha and apple cider vinegar can be easily mistaken for each other. They both have a distinctive amber hue, often with a slightly cloudy appearance. If you've ever glanced at a bottle of kombucha and thought, 'Is that just fancy apple cider vinegar?' you're definitely not alone. The fermentation process is the common thread that binds these two beverages together. Both kombucha and apple cider vinegar are products of microbial alchemy, where beneficial bacteria and yeasts transform simple ingredients into complex, flavourful concoctions. However, the similarities largely end there. The specific types of bacteria and yeasts involved, the ingredients they work on, and the resulting byproducts are vastly different. So, what sets these two apart when it comes to feeling the fizz or savouring the sour?
Key Differences
Have you ever reached for a bottle of what you thought was kombucha, only to discover, much to your dismay, that you had a mouthful of apple cider vinegar instead? The sharp, intense sourness hits you like a jolt. Not exactly the delightful experience you were hoping for, right?
Culture
Kombucha uses a SCOBY (Symbiotic Culture of Bacteria and Yeast) to carry out fermentation. The bacterial strains in SCOBY include acetic acid bacteria and lactic acid bacteria.
Read also: Exploring Apple Cider Vinegar and Cranberry Juice
Appearance
Kombucha is slightly effervescent, sporting hues that range from amber to peachy, depending on the tea and additional flavourings used.
Acidity
Apple cider vinegar is highly acidic and contains acetic acid. Apple cider vinegar is highly acidic, with a pH level of around 2 to 3. This acidity can be harsh on tooth enamel and the lining of the stomach if consumed in excess. Both kombucha and apple cider vinegar are acidic, with pH levels ranging from 2.5 to 3.5. However, apple cider vinegar tends to have a stronger tartness due to its higher acetic acid content.
Alcohol Content
Due to fermentation, kombucha contains trace amounts of alcohol (less than 0.5%).
Storage
Kombucha must be refrigerated after opening and is best consumed within a few months. To store kombucha, keep it refrigerated. Cold temperatures slow down the fermentation process and help maintain the beverage’s carbonation. Apple cider vinegar can be stored at room temperature or in the refrigerator. The acidity of ACV acts as a natural preservative, preventing spoilage. It’s best to store it in a cool, dark place away from direct sunlight. Unfiltered apple cider vinegar with the “mother” may form sediment over time, which is perfectly normal.
Cost
Store-bought kombucha can be pricier, but home brewing can cut costs dramatically.
Read also: A natural elixir for wellness
Flavor
Kombucha boasts a complex flavor profile characterized by a mild sweetness from its initial tea base, often accompanied by fruity or floral undertones, and a slightly tangy, bubbly quality due to the fermentation process. In contrast, apple cider vinegar offers a pungent sour taste with an apple essence, making it intensely tart and acidic.
Substituting Kombucha and Apple Cider Vinegar
Thinking about swapping your vinegar for a fizzy friend? What if you use kombucha instead of apple cider vinegar for your salad dressing? Would it give an off taste? Despite their similarities, kombucha and apple cider vinegar are not entirely interchangeable. However, with a little creativity and an understanding of their characteristics, you can substitute one for the other in certain situations.
- Kombucha in salad dressings: With its lower acidity and sweet-tart flavour, kombucha can be a delightful addition to salad dressings.
- Apple cider vinegar in kombucha-inspired marinades: For your next barbecue, consider using diluted apple cider vinegar for marinades that call for a tangy kick.
- Kombucha as a mild vinegar substitute: In recipes that call for a small amount of vinegar, such as sauces or pickling liquids, kombucha can be used as a milder substitute.
- Kombucha in personal care: Kombucha is a gentler substitute for apple cider vinegar in hair rinses.
- Kombucha in cleaning applications: Both ACV and kombucha contain acids that make them useful for cleaning. Diluted kombucha can be used to clean windows or remove soap scum.
Nutritional Comparison
Kombucha provides more calories, probiotics, and a wider range of vitamins compared to apple cider vinegar, but it may also contain varying amounts of sugar. Apple cider vinegar may help with weight loss, improve blood sugar control, and improve hearth health. ACV also contains trace amounts of minerals like potassium. Kombucha is prized for its probiotic content, which supports a healthy gut microbiome. These live bacteria can aid in digestion, boost the immune system, and improve nutrient absorption. However, it’s important to note that the nutritional content of kombucha can vary depending on the brand and preparation method.
Uses
Kombucha can be enjoyed straight from the bottle as a refreshing beverage. It’s often used as a healthier alternative to soda, providing a fizzy, flavorful drink with the added bonus of probiotics. Apple cider vinegar has a wide range of uses. Many people incorporate it into their daily routines by mixing it with other ingredients and drinking it as a health tonic. It can also be used in salad dressings, as a pickling liquid for vegetables, or as a tangy ingredient in sauces and marinades.
Kombucha and Kefir: Fermentation Processes
The production of both kombucha and kefir begins with a sugar-containing liquid and a culture of bacteria and yeast to kick off fermentation. Kombucha is fermented with the infusion of sweetened black tea followed by the incorporation of a starter culture, known as a ‘SCOBY’ (Symbiotic Culture of Bacteria and Yeast) [7,79,80] for a period of 7 to 10 days [80]. The SCOBY is a three-dimensional yellow-brown cellulosic zoogleal mat that contains acetic acid bacteria (AAB) and osmophilic yeast in a symbiotic relationship [80]. Appropriate quantities of ingredients are necessary to support the growth and activity of the SCOBY. Generally, 1.5-6 g/L of tea is added to 1 L of boiling water, which is then filtered and steeped with 70-90 g/L of sugar [81,82,83]. After the mixture is cooled, the SCOBY is added, along with some previously fermented kombucha beverage (10% v/v) [81,83] to lower the pH to below 4.6 [82]. The acidic environment is critical for preventing the growth of undesirable and contaminating microbes that could compromise the quality and safety of the final product [82,83]. The combination of these ingredients leads to a complex series of chemical and microbial reactions that drive the fermentation process [82] during which a new SCOBY layer forms on the surface of the liquid until it covers the solution completely [83]. The SCOBY layer becomes thicker subsequently [83], and when the uppermost layer of the SCOBY is fully formed, it can be harvested and used to initiate a new batch of kombucha [8,83].
The role of kefir grains in kefir is like what a SCOBY does for kombucha. Kefir grains are the primary ingredient required to make kefir. Kefir grains, unlike wheat, barley, or rice, are gelatinous polysaccharides containing a culture of bacteria and yeast known as kefiran. Kefir grains range in size from 0.3 to more than 2.0 cm in diameter and have irregular, folded, or uneven surfaces; their shape and colour (white to yellowish) resemble cauliflower florets [12,17]. They are also characterised by a tough and resilient texture composed of branched chains of glucose and galactose, as a result of the microbial metabolism of milk lactose with an acidic taste [84,85].
The ideal ratio between the grains and fermentation substrate of animal milk is between 1:30 and 1:50 (w/v) [86,87]. The grains are added to the milk and left to ferment for 18 to 24 h [88,89]. The fermentation process occurs typically within temperatures between 8 and 25 °C in a partially closed container [87]. Traditionally, fermentation has been performed in bags made with animal hides, which are regularly shaken to ensure that the milk and kefir grains are well mixed [12,90]. The micro-organisms responsible for the fermentation process mostly dwell on the surface of the grains, encompassing bacteria and yeast cells. The biomass of kefir grains slowly increases during the milk fermentation [12]. Once the fermentation process is completed, the kefir grains are separated from the liquid by filtration with a sieve and can be reused to make subsequent batches of kefir [87].
Kombucha and kefir are both fermented beverages made with a starter material that can be reused to make additional batches. The cultures aid in transforming, harnessing, and accessing the vitality and nutrients in the substrates. Kombucha is primarily made with black tea [91], whereas kefir has traditionally been made from milk substrates from cows, ewes, goats, or other types of milk [92]. Black tea provides a SCOBY with the necessary compounds, particularly purine derivatives, such as caffeine and theophylline, amply present in the tea [93]. Nevertheless, kombucha has undergone a massive transformation and is available in various variations today [94]. Studies have presented satisfactory outcomes in terms of their biochemical properties and kinetics [5,6,95,96]. With strong and increasing interest in kombucha, it has been suggested that the kombucha SCOBY could be used as an atypical starter in dairy products [97,98,99]. The kombucha SCOBY as a potential starter source in milk fermentation yields products similar to kefir or yoghurt [97,99]. The microbial species from the kombucha SCOBY and kefir grains can easily adapt to different substrates and lead to the development of new products.
As a result, for vegan, lactose-intolerant, and dairy-product-allergic consumers, nondairy substrates are made available for kefir fermentation [92]. Water kefir, an alternative to milk kefir, is cultivated in sugared water, with or without fruit extracts [92,100,101]. Fruit juices, vegetable juices, and alcohols are suitable media for the development of nondairy-fermented kefir.
Metabolic Pathways in Fermentation
In kombucha fermentation, sucrose from the medium is first hydrolysed to simple sugars, namely glucose and fructose, by the enzyme invertase (β-fructofuranosidase, EC 3.2.1.26), which is primarily produced by yeast species, such as S. cerevisiae [5,169,170]. Yeasts synthesise ethanol and carbon dioxide as metabolites from the resultant monosaccharides, which is then oxidised by AAB to produce acetic acid over the following days [171,172]. The actual processes in kombucha are catalysed by the two primary metabolites, ethanol and acetic acid; acetic acid (most characteristic product of kombucha) promotes yeast to make ethanol, whereas ethanol stimulates the growth and production of AAB [5,18,155]. Concurrently, AAB are responsible for cellulose synthesis from glucose and fructose, which makes up the SCOBY [5,91,150,172]. Additionally, d-glucose at the C6 position and the aldehyde group of the β-d-glucose at the C1 position are both enzymatically oxidised by AAB, resulting in significant amounts of glucuronic acid (GlcUA) and d-glucano-δ-lactone, respectively [169]. This latter metabolite is hydrolysed into gluconic acid by microbial enzymes [169]. Other organic acids, such as oxalic, succinic, malic, and citric acids, play important roles in the biological processes by acting as intermediates or end products in metabolic pathways [96,173]. In some circumstances, metabolically active lactic acid bacteria (LAB) can produce a significant amount of lactic acid [174].
Apart from the main metabolites, chemical constituents present in kombucha originate from the substrate itself, where their structures can be altered and transformed into new components during fermentation [5]. With tea substrate, kombucha contains most of the tea ingredients, such as various polyphenols, flavonols, catechins, catechin gallates, adenine, caffeine, theobromine, theophylline, gallic acids, tannins, gallotannin, potassium, manganese, fluoride ions, vitamins A, B, C, E, and K, and amino acids, particularly theanine [5,18]. Vitamin C, the most common vitamin found in kombucha beverages, is assumed to be derived from glucose and synthesised by bacteria [96].
Kefir fermentation is a complex interplay of various microbial strains, substrate compounds, grain-to-substrate ratios, and environmental conditions, all of which can substantially affect the final properties of kefir beverages [175,176]. The ingredients used in making kefir are milk and kefir grains, which contain a mixture of yeast, LAB, and AAB [12,16,175]. During kefir fermentation, yeast is responsible for the lactose conversion to ethanol and carbon dioxide [9,176]. Lactose is also hydrolysed through the lactose permeate system (LPS) or the phosphoenolpyruvate-dependent phosphotransferase system (LPPDPS), present mainly in LAB [177,178]. The LPS hydrolyses lactose into glucose and galactose, while the LPPDPS hydrolyses lactose to glucose and galactose-6-phosphate, via the action of the β-galactosidase enzyme [177,178]. LAB utilise two primary pathways for lactose metabolism: the homofermentative pathway, resulting in the production of lactic acid, and the heterofermentative pathway, producing a combination of end products including carbon dioxide, ethanol, acetic acid, and lactic acid [177,178,179]. Acetic acid is also produced by AAB [180]. The accumulation of organic acids from these pathways allows kefir to delay the development of pathogenic micro-organisms considerably [85]. Beyond the formation of organic acids, LAB also produce flavour compounds, such as acetaldehyde, diacetyl, and acetoin [12]. At the same time, kefir fermentation also results in the production of other metabolites, including amino acids, peptides, and vitamins [181].
Choosing Between Kombucha and Apple Cider Vinegar
Kombucha vs. With kombucha and apple cider vinegar boasting a range of potential health benefits and unique flavour profiles, it's easy to get caught in a 'which is better' dilemma. You might wonder whether to drink kombucha, apple cider vinegar, or both. The truth is that there's no single better option. The choice between kombucha and apple cider vinegar depends on your preferences and health goals; kombucha is a fermented tea beverage with potential probiotic benefits and a unique flavor, while apple cider vinegar is a fermented vinegar often used for its potential digestive and weight management benefits.
If I had to pick one, it would be kombucha. It’s a refreshing, fizzy, beverage that’s a great source of probiotics to support gut health. Plus, it tastes 100 times better than apple cider vinegar. ACV is much stronger and has to be diluted with other juices to make it palatable for drinking.
Conclusion
So, what do you think now? Is kombucha like apple cider vinegar? Though they share similarities as fermented products, they are distinctly different beverages, each offering a unique tangy experience. Explore both kombucha and apple cider vinegar, experiment with different flavours and uses, and discover which one best suits your taste buds and health goals.
In summary, kombucha and kefir are two fermented beverages that have similarity in terms of the incorporation of a sweetened medium and a starter culture containing yeast and bacteria to embark on the fermentation process. The sugar in the starting ingredients transforms into a plethora of metabolites including organic acids, alcohols, and gases. Despite the similarities in production, there are differences between kombucha and kefir in terms of the distinctive types of yeast and bacteria that result in variations in their nutritional profiles and flavours.