About beer through the eyes of a chemist. Part 3

About beer through the eyes of a chemist. Part 3



Hi% username%.

While you're digging into your device, we continue the topic of beer, which has already been partially disclosed here , a little more - here , but still not resting on our laurels!

I am infinitely glad that I decided to stretch it into a series of articles, as I understood from the comments: many questions that seemed insignificant at the very beginning should be disclosed - and if I wrote one article, it would be either incomplete or too long and tedious .

And so - we have the third part and, I hope, no less interesting. And I am writing it deliberately early on Sunday, so as not to spoil the beginning of the work week. I'll ruin her already in the following parts :)

Let's go.

I'll start with the promised Guinness story and St. Patrick's Day.

The main Irish holiday has long been firmly associated with green color, parades , drunk red leprechauns and Guinness beer. But this is also strange - after all, how does St. Patrick, and indeed the adoption of Christianity in Ireland, have anything to do with Arthur Guinness and his factory, which appeared much later?

Actually, no - more than that: until the 60s of the last century, all the pubs were closed on St. Patrick's Day, because selling any alcohol, including beer, was forbidden, which is correct, after all, the first holiday all religious. But since the Irish are such Irish, on March 17, in parallel with the adoption of Christianity by Ireland, people at the same time honor Irish culture.

Actually, it was for the “culture” of the holiday that the producers of “Guinness” grabbed. Entrepreneurial Irish brewers, having solid budgets, not only actively promoted their products during the holiday, but also lobbied to hold them in different countries. You didn’t know,% username%, but in Malaysia it's very honorable to celebrate St. Patrick's Day just because of the local company division. In Canada, where the holiday is already very popular, representatives of the brewery in general actively stoked to make it a national holiday.

In general, we must pay tribute to the company: she did everything so that at the word “Ireland” people all over the world would first of all remember the famous stout and absolutely sincerely consider it the main beer of the holiday. According to statistics, sales of “Guinness” on St. Patrick's Day increase about 10 times. Learn healthy marketing,% username%!

About Guinness, we still remember more than once, but for now let's continue about the ingredients of beer. We have quite a bit left - and all optional.

Hops


So let's start with the fact that hops (lat. Húmulus) - a genus of flowering plants of the family Cannabis. Yes, hop cones are the relatives of the very cones that you and some of your serious uncles and aunts are interested in having and on your balcony. But at once we debunk one of the myths: hop, contrary to the meaning of the word “get drunk” and the presence of dubious relatives in the family, does not affect the strength of the beer, but it has a mild sedative effect that is inferior in strength to valerian. Valokordin, Valosedan, Novo-Passit, Korvaldin, Sedavit, Urolesan - preparations containing hops or its components. Let's be frank: “hops” is mostly alcohol, not hops, which at best relaxes and soothes.

Hop cones contain 8-prenylnaringenin - a substance belonging to the class of phytoestrogens (phyto - plant, estrogen - female sex hormone), which gives the hop estrogenic activity. In experiments on castrated mice and infantile rats, it was found that 70% of the hop extract at a dose of 10-30 mg causes estrus or proestrus.Daily administration of hop extract to animals for 12 days increased the mass of the horn of the uterus by 4.1 times. The addition of 8-isoprenylnaringenin to drinking water in mice with ovaries removed caused estrogenic stimulation of the vaginal epithelium. However, the effect was achieved at a concentration of at least 100 µg/ml, which is 500 times higher than the content of 8-isoprenylnaringenin in beer.

On the effect of phytoestrogens of hops in beer on the human body there is a mass of supposedly sensations: women participating in the harvesting of hops violated the cycle, and there man’s catastrophic dignity - however, the sensations do not take into account that the phytoestrogen contained in the hops about 5,000 times weaker than animal estrogen. Therefore, in order to grow a beautiful elastic breast, you will need to consume about 5-10 tons of beer each day. So forget all about the terrible words "estrus" and "proestrus", stop trying on your horns and look for the vaginal epithelium - or rather pour some more mug.

Hop is an optional beer ingredient. Previously, instead of it, special herbs were used in the production, while the goal was still the same: to balance the sweetness of malt with the bitterness of herbs. Beer can be brewed without hops, but in this case it will turn out unbalanced and tasteless.

Hops affect the noticeable characteristics of beer: the aroma, the taste in general and, in particular, the degree of bitterness. Bitterness is a key indicator, below we will analyze it in more detail. Adding hops in the early stages of beer production will lead to an increase in bitterness and a noticeable change in taste, and in the later stages it will mainly affect the aroma - citrus, passion fruit, floral, mango, herbal, earthy and other flavors of beer appear due to hops, and not because of nice additives. starting with the letter "E" and the numbers after. But do not flatter yourself,% username%: one of the noble aromas of beer is a mixture of cat urine and black currant smell - this effect gives a large concentration of Simcoe hops, but the smell of freshly brewed coffee, which you may have been attracted to in the neighboring beer house - on the contrary, the aroma ignoble and considered unacceptable for beer. It appears due to the oxidation of hops, when the beer is exposed to sunlight - more on this again a little later.

Like the malt, several different hop varieties can be used in the production of a beer variety at different stages. Thus, it is possible to achieve very interesting taste and aroma properties of the drink, and therefore a huge number of different varieties of brewing hops are cultivated in the world, and new varieties appear every year. However, literally dozens of varieties are the most used, while the most famous are from the Czech Republic and the USA. One of the most famous and recognizable hops is Saaz, aka Zhatetsky. It is used in the production of a huge number of lager varieties, gives a subtle bitterness and a recognizable earthy-spicy aroma with notes of herbs. If you drank classic Czech varieties or, say, Stella Artois lager, then you are familiar with what I'm saying.

Pressed hops in the form of granules are often used in production (it is believed that this was one of the reasons for the appearance of the myth about powdered beer): this way it is stored longer and retains its properties, while the quality of beer doesn’t suffer at all.

In Belgium, leaves and young shoots of hops are used for salads, added to soups and sauces. In Romania, young shoots are consumed as asparagus. For a long time, hops have been used in bakery production in baking bread and various confectionery products. Hops are also used in the production of not only beer, but also honey wines: it improves its organoleptic characteristics, contributes to the natural clarification of honey wine and protects it from souring.

But the main thing that hops in brewing are valuable for is alpha-acids. So called quite complex compounds such as humulone.

Here is a handsome humulon


Depending on the variety of hops, its growing conditions, age at harvest and the drying process, the concentration of humulone can be different, for example:

  • Cascade 4.5-8%
  • Centennial 9-11.5%
  • Chinook 12-14%
  • East Kent Goldings 4.5-7%
  • Hallertauer Hersbrucker 2.5-5%
  • Mt. Hood 3.5-8%
  • Saaz 2-5%
  • Styrian Goldings 4.5-7%
  • Willamette 4-7%

By the way, besides Humulon, there is also cohumulon, adhumulon, posthumulon and pregumulon. In addition, there are also beta acids: lupulone, colupulon and adlupulon. They broadcast a slightly rougher bitterness in beer than alpha-acid. But, since they do not dissolve so well, their contribution is much less, and therefore alpha males acids win.

When heated, alpha-acids undergo isomerization, so isogumulon is formed from humulone: ​​



It is isohumulone adopted by the standard of bitterness in the chamber of measures and weights , and the mysterious abbreviation IBU, meaning international units of bitterness - International Bitterness Units, essentially indicates what concentration of isohumulone in water in mg/l corresponds to the bitterness of a particular beer. It is believed that the limit of recognition of bitterness for a person is approximately 120 IBU. Anything greater than this value will be treated the same. It is worth bearing in mind when meeting beer with very high rates of bitterness, besides, there is no point in drinking beer with a low IBU after a high value - taste buds will “get clogged” and you just won't appreciate the taste.

By the way, beta acids are not isomerized, as alpha acids do. Instead, they slowly oxidize. Since this process takes more time, the longer the beer is fermented and aged, the more powerful the effect and noticeable bitterness.

Isohumulone is just one of the representatives of iso-alpha-acids, but they all have another undoubtedly important effect: they have a bacteriostatic effect on many gram-positive bacteria. First of all, it suppresses the reproduction of bacteria responsible for lactic fermentation - that is, it protects the beer from souring. On the other hand, iso-alpha-acids do not act on gram-negative bacteria, and therefore the brewer is obliged to monitor hygiene and sterility if he wants to get a beer at the outlet, and not smelly and sour swill.
Taking into account these factors, it becomes clear why in the Middle Ages beer was preferred instead of water: the smell and taste of the drink was an excellent evidence of its contamination with bacteria, which cannot be said about the water itself.

Iso-alpha-acid, however, like other substances entering the hops, is extremely important for the foam: if the malt caused the formation of foam, then the hop affects its durability. This, by the way, is especially noticeable in the example of simple light lagers with a small density: some Miller should not be poured into a glass, you should not get a dense, resistant froth.

However, it is precisely the alpha-acids that lead to what is called “skunky beer” - literally: “skunk beer”. In the presence of light and oxygen, these substances decay as a result of a reaction catalyzed by riboflavin, with the formation of free radicals as a result of the homolytic cleavage of the exocyclic carbon-carbon bond. The cleaved acyl side radical then decomposes again, generating a 1,1-dimethylallyl radical. This radical can react with sulfur-containing amino acids, such as cysteine, to form 3-methylbut-2-ene-1-thiol - and this product causes the smell of a skunk. However, in very low concentrations, the smell is felt like that of freshly roasted coffee.

In any case, the decomposition of iso-alpha-acids is an extremely undesirable process, and the more hops in the beer, the faster it will degrade, losing flavor and bitterness. Therefore, hopped beers should not be stored for a long time: beer can lose half the aromatic properties within a few months after production. All the more stupid to keep it open. For the sake of justice, it must be said that such degradation is peculiar not only to IPA, but to any style of beer in general, which is characterized by a noticeable intoxicating component: these are all kinds of variations Pale Ale (APA, NEIPA, bitters, etc.), and pilsners (the main part of Czech beer), and even helles (German lagers like Spaten, Lövenbroy, Weihenstephaner and the like). It makes sense to drink all this beer as fresh as possible and not to forget it in the refrigerator or, especially, on the shelf in the cupboard for many months. Even being open before the expiration of the specified expiration date, it is likely to turn out to be not so tasty.
To eliminate possible decay, in the production of beer special attention is paid to the possibility of UV radiation to reach the beer, as well as the concentration of oxygen in the water. At some breweries, oxygen concentrations are at the level of tens of µg/l and even lower - so that you understand% username%, we are talking about the levels allowed in the cooling circuits of nuclear reactors.

By the way, today it is known about 250 types of essential oils present in hops. In a high concentration in the plant contains myrcene, gumulen and karyofillen. The second of them makes the most tangible contribution to the taste and aroma of a foamy drink. Overseas hop varieties contain more myrcene than European ones. It adds more citrus and conifer notes. Cariofillen brings a touch of spice, gives the beer a sharper taste. In a mixture with the already mentioned esters, which are formed during fermentation, it can turn out such a complicated perfume that Rive Gauche and L'Etoile rest.

Gas


Yes,% username%, gas can also be considered as a component of beer.

The first gas in our list - carbon dioxide - is one of the waste products of yeast. At the same time, the amount of carbon dioxide in a brewing beer depends largely on the desire of the brewer/technologist, but it almost always differs depending on which container the beer is poured into. And this is the key point.

In general, we can say the following: gas is always needed - on the one hand, it displaces harmful oxygen from a solution, and on the other, it causes the formation of foam when opening a beer.

Often, beer that is sold in a can or bottle is self-saturated with gas during different stages of fermentation or continues to do so already on the shelf in cases with the so-called live beer, fermenting in a bottle. In other cases, the manufacturer can forcibly carbonate the beer with carbon dioxide to the desired level - this is fast and convenient. This is often done if the beer is intended for further tap filling at a bar or shop. At the same time, of course, the gas produced by the yeast does not differ in any way from that added from the cylinder. But of course you can believe in “biocarbon dioxide” and pay at exorbitant prices in full accordance with the theory of the benefits of pumping up the wheels with nitrogen. Good luck.

So, beer packed in special barrels (kegs) that left the factory has the required degree of carbonation (carbonation). At the same time, on-site bottling, that is, in a bar or filling shop, will have to maintain this degree. To do this, a gas cylinder (carbon dioxide or nitrogen mixture) is connected to the filling system: its task is not only to push the beer out of the keg, but also to maintain the gas level at the proper level.

Actually, depending on how much pressure is put in the filling system, a different volume of gas enters the beer, due to which it can give different sensations during consumption. And this is one of the reasons why the same variety in bottling can be perceived differently in different places and differ from its bottle and canned versions.

In addition to carbon dioxide, nitrogen deserves special attention. As it turned out 60 years ago, the difference in the properties of carbon dioxide and nitrogen changes a lot.

Think of the Guinness Draft just poured into a glass of draft. A thick cream hat, below it - falling bubbles that form the same “avalanche effect”, and the beer itself - as if slightly creamy, barely aerated, with a soft texture - all this is a consequence of the use of nitrogen in the Guinness draft.
Actually, it was for the first time that the producer of the now world-famous Irish Stout became the first to use this gas when pouring beer, but this did not happen because of a good life. The famous brewery could hardly withstand the competition in the first half of the 20th century with the spill varieties that gained popularity at that time, especially lagers, and could not do anything about it: Guinness was either sold warm in bottles or, at best, filled with carbon dioxide, which worsened the taste of beer and significantly slowed down the process of filling. The people demanded cold and quick. It was necessary to do something.

The problem was solved by an employee of the Irish brewery Michael Ash: being a mathematician by training, he was put by the leadership at the head of the team, which was to develop a technology to extend the shelf life of the bottle Guinness. Ash not only drew attention to the best air removal efficiency when using nitrogen instead of carbon dioxide, he and his team developed a system that made it possible to quickly pour stout directly from the barrel using a mixture of different gases, including nitrogen. As a result, in 1958, the new system was patented and gradually came into use, raising sales of Guinness by a quarter. By the way, they almost simultaneously patented the addition of a plastic ball with compressed nitrogen to a canned beer, which bursts when opening a can and “foams” beer.

Now on the planet there are hundreds of varieties supplied to the bottling with the help of nitrogen, and more precisely with the help of a mixture of nitrogen and carbon dioxide: mainly in the ratio of about 80% to 20%, respectively. Mostly bottling on nitrogen can be found in the English and Irish ales and, in particular, stouts, but sometimes you can find more atypical varieties for nitrogen filling, for example, lager.

However, I must say that with this, of course, there are some speculations - I am now talking about all sorts of "Nitro IPA": Guinness Nitro IPA, Vermont Nitro IPA and others. The fact is that IPA (India Pale Ale) is a style of beer, in which the main role is played by the intoxicating component. Eli in the IPA style does not have to be wildly bitter (this trend has already passed), but there should be a specific hop bitterness in such a beer. Beer lovers appreciate the IPA and its varieties for strong hopping.

Capsules in banks with Nitro IPA contain nitrogen (or rather, a mixture of nitrogen and carbon dioxide). Nitrogen gives beer certain characteristics: dense creamy frothy cap, pleasant texture and drinkability. Nitrogen beer is perfectly drunk, it seems easy and understandable.

But besides this, nitrogen has one more feature, rather insidious: it hides behind itself some of the taste nuances of beer. In particular, it masks the bitterness. And if the classic loose stout "Guinness" or simple and clear ale "Kilkenny" nitrogen only helps to become better, then for hopped beer, it becomes the main enemy. Nitrogen takes little from IPA, than this beer should stand out among others.

For this reason, any “IPA” on nitrogen will not give the main thing that it should have given - pleasant, dry, intoxicating bitterness. Rather, she will try, but the gas escaping from the capsule will prevent it: it will make the beer light, pleasant and drinkable, and also show beautiful bubbles running in cascade along the walls of the glass, but will deprive you of the very three letters that were inscribed on the can .

In short, “Nitro Ipa” is a product of the desire of marketers to cross a bulldog with a rhinoceros with the corresponding result.

By the way, since I touched the theme of the foam, I’ll add some more. Foam significantly affects the perception of taste and aroma of beer. In contact with taste receptors, it is she who gives us the feeling of softness of the drink, and its absence or, on the contrary, the excess can significantly change the taste sensations. Pour German wheat into the glass, let the foam settle (you will have to wait) and try. Now pour a new portion into another glass so that a frothy cap is formed and take a sip: believe me, you will definitely feel the difference.

Interestingly, even the shape of the glass affects the amount of foam. In particular, the narrowing at the bottom of a classic glass for wheat beer is precisely so that each time you tilt the glass, foam is formed, which is necessary for this style of beer according to the standard. Temperature also plays an important role: for example, if a draft beer is stored at too high a temperature, it will froth strongly when pouring. The same is true even for warm bottled or canned beer: I think there is no one among beer lovers who didn’t pour foam at least once when opening a bottle on a hot day.

By the way, if you seize beer with fatty food, the foam will be noticeably less: with each contact, the remaining fat on the lips prevents the proteins from forming foam and destroys it.

So the next time, trying to pour beer with a minimum of foam, remember: most likely, you are right now voluntarily depriving yourself of too much pleasure from the drink.

By the way, respect for the foam is a good indicator of the level of knowledge and skills of the bartender. In the right brasserie they never pour a beer without a froth if it should be there. And it should be there in the overwhelming majority of cases, with rare exceptions: when beer foams poorly by nature (for example, so-called Kask ales or American light lager).

So do not rush to blame the bartender that he tried to deceive you by bringing a glass with a froth - most likely you yourself are deceiving yourself.



Well, probably enough for today, and in the next part we will talk about the last ingredient of beer - various additives, let's see, but are they really superfluous, what do Germans and Belgians think about this, also GOST 31711-2012, GOST 55292-2012 and Russian government in general - and also estimate who needs it. There will be a lot of information, and even more - is left behind the brackets, so most likely the part will not be the last.

Source text: About beer through the eyes of a chemist. Part 3