Malt vinegar, condiment of the gods–at least with fish and chips. This revered condiment is enjoyed worldwide but primarily in the English speaking world: the United Kingdom, United States, Canada, Australia, etc.. Its dark color and characteristic aroma and taste make it a mainstay of pubs as a favored condiment on fries (chips in the UK), chips (tortillas), or any other food.
What exactly is malt vinegar though, and how does it relate to its relatively unknown cousin, beer vinegar?
First, to understand malt vinegar you need to understand a bit about the traditional process of making beer. Grain, mostly barley but also other grains such as corn, wheat, or rye, is milled (crushed) and sparged with hot water to activate enzymes known as amylases that naturally occur in the grain. These enzymes convert the starch in the grain to sugar to produce wort, a sugary solution that is then further processed by boiling and the adding of hops to make beer.
The starter for malt vinegar is the sugary wort that is fermented directly to alcohol with yeasts without additional processing or addition of hops. Historically, only malted barley was used but in modern times up to half can be another malted grain such as corn or wheat depending on the requirements of flavor and cost. The yeast is pitched into the wort and is allowed to proceed until the resulting “low wine” is completely dry and almost all the sugar has been consumed. Once this malt low wine is finished, it is placed into vinegar generators and converted to vinegar. This is how almost all malt vinegars be it Heinz, Sarson’s, or others are made.
There are a few differences in the post-processing that differentiate American vs. British malt vinegars. American malt vinegars are typically just that–malt vinegar fermented from the low wine and adjusted to an acidity of 5%. This includes the brands of Heinz, London Pub (made in New Jersey by World Fine Foods), and Holland House (made in the US by Mizkan, who also now owns Sarson’s). Nothing else is really added.
The British style malt vinegars, typified by Sarson’s, usually add a compound for sweetening and dark color. For Sarson’s, that is malt extract syrup. Using a hydrometer, I measured the specific gravity of Sarson’s malt vinegar at 1.014, or about 4 Brix (4g sugar per 100 mL of vinegar)*. This helps give Sarson’s the richer texture and slight sweet taste that differentiates it. Some other malt vinegar companies around the world will add caramel instead of malt extract syrup; this technique is similar to that of balsamic vinegar manufacturers who can add caramel for color and taste as long as it is not “Traditional Balsamic” of Modena or Reggio Emilia. Some malt vinegar manufacturers historically added salt as well though this is no longer as common.
Beer vinegar on the other hand is just that–vinegar made directly from beer.
To make malt vinegar at home, you should start with liquid malt extract such as that you find in homebrew shops or online. Usually a 3.3 lb canister will yield 2 – 2.5 gallons of wort with the right amount of sugar to make 5% vinegar. Pitch the wort with your yeast of choice, wait for alcoholic fermentation to cease, strain out the yeast, and then add mother of vinegar to the low wine. After 8-12 weeks you should have good malt vinegar which you can age to your liking. You can also add salt, liquid malt extract, caramel, or other additives depending on your taste and color preferences
For beer vinegar, you can use whatever your favorite beer is and add mother of vinegar. You can add ingredients to beer vinegar as well but this is not typical in beer vinegars.
*Update: After obtaining a variety of malt vinegars and testing their sugar content I can confirm that UK malt vinegars (Sarson’s, Crosse & Blackwell) both have specific gravities around 1.014 (4 Brix) while US made malt vinegars are slightly sweeter with Heinz and Holland House (Mizkan) both testing at 1.02 (5 Brix). Roast barley malt extract is typically the additive used to provide color and sweetness. It seems besides the Sarson’s light malt vinegar most malt vinegars are not dry like their wine and apple cider equivalents.