The science of vinegar. Part 4. Malt vinegars with Nordic flavours.

Review.

Traditional malt vinegar, which in the Nordic countries often watered fish and potatoes, is not of great culinary interest. But it was there that we found inspiration for the development of vinegar based on beer, which had great potential for complex and interesting tastes. The experiments consisted in the use of two types of malt – beer bases. For one, we turned into a wort and fermented barley malt for light beer about the same way as they do in home brewing. For another, we brewed a koji beer using koji instead of wort. But the results were unsatisfactory, so we tried another type of grain alcohol. We made a sake from barley koji and were satisfied. To our basics we added a variety of Nordic plants with bright flavors and left to ferment for another 3-4 months.

After our descriptive analysis, we were eager to continue experimenting, especially with approaches to alcoholic fermentation and adding flavors. We were wondering if we could better incorporate Nordic flavors such as pine, licorice and juniper into stable, clear vinegars with bright and whole flavors and the potential for aging?

The obvious next step was to investigate a three-stage process: yeast fermentation from sugar to alcohol, followed by the addition of non-fermentable aromatic ingredients (either in the process or immediately after fermentation), followed by slow (3-4 months) passive fermentation in vinegar, following the addition of raw vinegar as a starter culture.

Sugar and alcohol.

The initial ideas for sources of sugar that could make a pleasant but not overwhelming flavor to vinegar, and besides would be available in winter (in support of our interest in seasonality) and well-fermented, were juices: Apple and birch. In order to achieve a concentration of sugar, giving a fairly pleasant vinegar, Apple juice can be evaporated to the syrup, and then add raw juice . In the same way, birch syrup, which has a much more fruity flavor than maple syrup, can be diluted to the required concentration of sugar. We suggested that both of these sources of sugar should give us if not a clean canvas, then at least a quality basis for the development of other aromatic ingredients.
At the same time, we conducted a separate experiment with ale, hopped insects, and realized that beer malt is another almost ideal base for vinegar. Relatively inexpensive, publicly available and providing a huge variety of flavors (any beer, by definition, includes malt; the difference in flavors between, say, camps, lambics, light beer, Baltic porters and quadrupels speaks to the versatility and diversity of brewing as a process) and quite easy to work, malt has also allowed us to explore vinegars made from special types of beer. Traditional malt vinegar is one of the most widely produced commercial types of vinegar, but despite its ubiquity in the classic “fish & chips”, commercial versions are of little culinary interest. Our project the next level focuses on getting the most cheap vinegar from malt, and the study of the potential of malt to the maintenance of complex delicious flavors.

We brewed and fermented barley malt for light beer (supplemented by some other malt) in batches of 8 to 30 liters with the help of techniques familiar to home brewers. Using convenient online calculators, we estimated how much malt we would need to get the necessary sugar content. About 80% of the mass of malt can be converted into sugar, and somewhere between 60% and 90% of this sugar can be extracted from the grain, which in turn gives a certain level of alcohol and after acetic fermentation a certain concentration of acetic acid. We milled the malts in a grain mill, small enough for efficient extraction, but not too fine to allow the particles to not mix with water and lead to “stuck” or slow fermentation.

Our barrel!

Malt and hot water were mixed in a heat-insulated container and kept at a temperature between 64 and 69 grudus, at which the amylase enzyme in malt is most active, grinding long starch molecules into small sugars that can be metabolized by yeast into ethyl alcohol. At the lower limit of this interval (64-65°C), beta amylases are more active, leading to a higher proportion of disaccharides (called “maltose” or “malt sugar”) that are fully absorbed by yeast. At the upper limit (64-65°C), another enzyme, alpha amylase, becomes more active, and this illegible vinegar digester produces maltose molecules on a par with a variety of other, larger oligosaccharides called dextrins, which can introduce viscosity, “body” and sweetness, but are not digested by yeast. Thus, cool wort gives a drier, stronger beer, while hot wort turns out to be a sweet, viscous, light drink. In most portions we kept to the lower limit, but a couple of times closer to the end of the process we still heated the wort to the upper limit to get a little more “body” and sweets in the final vinegar.

Often projects that seemed to be something new turned out to be reinterpretations of ancient traditions. During the fermentation of malt, for example, naturally raises the question of whether to add hops to the mixture. For vinegars with a distinct beer taste, this would be logical, but we also wanted to make at least a few vinegars, whose tastes would be on a par with malt and other aromatic ingredients. A small study of the history of brewing showed that non-starchy Beers that we have turned out, were in fact much closer to the medieval and prannesovremennym versions of ale, which did not contain hops until about between 11 and 16 centuries. Absolutely devoid of hops alcoholic malt beverages were called, at least in England, "Ales" to distinguish them from versions with the addition of hops imported from the Netherlands, which were called "beer". Adding foods such as pine needles, juniper wood and berries, collected herbs in the filtering process or to the finished filtered the wort is a much older method of brewing called “Gruit” (which typically also included bog Myrtle, yarrow and/or Heather), or are still popular in Finland “sakhti”, which is prepared with juniper berries and filtered through juniper twigs.
At the same time, when we were developing beer vinegars, we started experimenting with roasting koji, which caramels the sugars in koji and creates new flavors, similar to coffee or chocolate, but clearly isolated. Our friends in The noma test kitchen found this great use in a dish-analogue of the mole (a diverse group of Mexican sauces, some of which include cocoa), and we collaborated to use roasted koji in vinegars: made it into alcoholic teas in the style of pine-vinegar-version-1.0, and also added it to the wort from the usual malt. Exploring the different degrees of roasting, ratio and fermentation path, we made koji-beer of various colors, strength and flavors, which then slowly, with the addition of herbs and flowers collected, continued its way to the transformation into vinegar. For the recipe for the first light beer from roasted koji, see our post about roasting.

Fried barley koji.

It seemed logical to us to also try to brew beer directly from barley koji, and not in the form of additions to malt fermentation. Treating koji as a malt-brewing it with water at Pro-amylolytic temperatures (64-68°C) — proved pointless, since the yield was small and it seems that the process included some proteolysis activity, which led to the appearance of a strange taste, which is hardly pleasant. On the other hand, koji sake was good. Unlike extraction through brew and warm in the manufacture of beer, the making of sake involves the cultivation of Aspergillus oryzae on the grain (in this case barley) for the preparation of koji, which has a sweetness and full amiloliticescoy enzymes, with the subsequent blend cold water, extra steamed barley and yeast. Koji gradually turns the starch in the steamed barley into sugar, and yeast metabolizes sugar and turns it into alcohol. The sake is then filtered off from the seed cake, mold and yeast cake, and this cake, which still has enzyme activity, can be used for marinating (as in traditional Japanese kasu-zuke) or other purposes.
After fermentation of our beer/gruit with yeast under a water tap, we shared the large portions and added aromatic ingredients, along with filling vinegar, which we made 20% in order to control the comparison. Each serving of vinegar received a rag cover for free oxygen access, and we kept them in a safe place until later times, when we planned to conduct a more formal touch analysis.