Vinegar 101: What is a vinegar mother?
From the desk of Sam Reese, Director of Operations (pictured above with a vinegar mother)
So... what is a vinegar mother anyways? At Red Truck Orchards, we talk about mothers a lot. Like, probably too much. Our fermentation tanks all bear our mothers' and grandmothers' names. We call our production facility the mothership. We even have a great big neon sign that says love your mother. It's getting a little out of hand. And as much as we love our actual mothers (and we do!), these are all just cheeky references to a different kind of mother: one that plays a critical role in the production of our Original Cherry Vinegar. And all vinegars, for that matter. The mother of vinegar.
What is a mother of vinegar? And what makes it so special and unique to our process? What does it look like, what does it do, and why should it matter to you?
Colloquially, the mother of vinegar (aka vinegar mother, we won't correct you) refers to the characteristic, visible, occasionally gelatinous mass that forms in some vinegars. Technically, we call this formation a biofilm: a matrix of cells that grows on the surface of vinegar during fermentation. This matrix is composed largely of acetic acid bacteria, or acetobacter, which is the microorganism responsible for metabolizing alcohol into vinegar. It also contains cellulose created by those same acetobacter cells, which explains the mother's typical semi-solid texture. If you are familiar with kombucha-making, the mother is very similar to a kombucha scoby (an acronym for symbiotic culture of bacteria and yeast), though mothers are typically less dense and contain little to no yeast in their microbiome. In fact, some mothers of vinegar are barely visible at all, and their morphology (or appearance and structure) can run the gamut from a thin and wispy spider-web-like film to a dense and heavy puck of solid gel. It all depends on the mother's environment, food source, pedigree, and microbiological composition.
Despite our mothers' variety of shapes, sizes, textures, and colors, they all have one thing in common: we rely on them to create vinegar.
In a similar way that specially selected yeasts turn our cherries into wine by metabolizing natural fruit sugars into alcohol (ethanol, to be exact), our specially cultured mothers turn that cherry wine into cherry vinegar by metabolizing ethanol into acetic acid, the primary organic acid in vinegar. Without the vinegar mother—and the acetobacter therein—there's no vinegar. So naturally, we're a bit dependent on our vinegar mothers, and much of our production process revolves around caring for them, monitoring their progress, and observing how they react to changes in their environment. We may not be able to see the individual bacteria that comprise the mother, but through lab data and regular sensory analysis, we can see how our bacterial cultures react based on the aromatic and flavor-active compounds they produce (or suppress), the speed and efficiency of their acidification, and the rate of their willingness to accommodate conditional changes.
All this being said, the mother of vinegar is also akin to the tip of the iceberg: what's under the surface of that biofilm matters, too. A healthy mother is only an indicator of an active biome of acetobacter throughout the entirety of the batch of vinegar; it's not the whole biome in and of itself. Sometimes mothers, which tend to float on the surface of the liquid, lose their buoyancy and sink to the bottom. When this happens, a new mother appears within a day or so. Because acetobacter is an obligate aerobe—a microorganism that requires oxygen to grow—it prefers to hang out at the liquid-to-air threshold on the vinegar's surface. Its production of cellulose aids in the bacteria's ability to concentrate at this threshold, but there are plenty of bacteria throughout the liquid, waiting for their turn to breach the surface, sip some wine, and multiply. Rough life, right?
This helps explain one of the more common misconceptions folks have when they purchase a bottle of vinegar; specifically, what does it mean when a vinegar label says with the mother? Why is the vinegar mother important?
After all, exceedingly few of these bottles have that characteristic, gelatinous layer of cellulose on top. That's because that layer will only form in the presence of oxygen; in a sealed bottle, oxygen is very scarce. When we say a vinegar is packaged with the mother, we mean that all of the happy, healthy, mother-forming bacteria are alive inside. In fact, if you were to take a bottle of our vinegar, open it up, and leave it uncapped on your counter for a few days, you'd likely see a small, thin, nearly transparent mother form on the surface. Because you provided it with oxygen, the bacteria responded by creating a biofilm: a mother!
Relatedly: on occasion, you will find sediment on the bottom of our cherry vinegar. Is this the mother? Well... yes and no. The sediment consists mostly of tiny bits of cherries. We don't use filters to remove all of the color and cloudiness from our vinegar, because doing so results in a less flavorful, less wholesome vinegar. We put a lot of effort getting all that fruit in there (more on that in a future blog!), so we aren't too keen on stripping it all out. As such, some of those pieces of cherries find their way into the final product. Entrained in that fruity sediment—as it is throughout the vinegar—are billions of live bacterial cells. At least, that's the case in our vinegar.
Sediment itself isn't an indicator of a mother, nor the presence of live, beneficial bacteria.
For a vinegar to truly be packaged with the vinegar mother, it must be absent of any additional preservatives (like metabisulfite, sodium benzoate, and other additives designed to eliminate live microbes), and it must never be pasteurized with heat. These practices destroy acetobacter, and vinegars produced in this manner contain no beneficial bacteria, and therefore no live vinegar mother.
That's not to say that you can't make vinegar in this fashion. We just prefer our mothers alive versus dead (don't you?). Vinegar is a living thing, and it's nature's natural preservative, achieved by billions of tiny mother-forming bacteria performing metabolic processes that existed and persisted long before we discovered them. At Red Truck Orchards, we are committed to a passion for preservation: not only of our community of local cherry growers, but of the fruit we grow and the products we make with it. To that end, we are similarly committed to the preservation of traditional vinegar-making methodology: honoring our fruit, respecting our microbes, and loving our mothers.