{"id":34389,"date":"2019-10-31T21:58:03","date_gmt":"2019-10-31T18:58:03","guid":{"rendered":"https:\/\/prohoster.info\/blog\/o-pive-glazami-himika-chast-2\/"},"modified":"2019-10-31T21:58:03","modified_gmt":"2019-10-31T18:58:03","slug":"o-pive-glazami-himika-chast-2","status":"publish","type":"post","link":"https:\/\/prohoster.info\/en\/blog\/news\/o-pive-glazami-himika-chast-2","title":{"rendered":"Beer through the eyes of a chemist. Part 2","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<p><img decoding=\"async\" alt=\"Beer through the eyes of a chemist. Part 2\" src=\"\/wp-content\/uploads\/2019\/05\/3d6d10f43fc5dcfd3dcf66e1566879ed.jpeg\" style=\"display:block;margin: 0 auto;\" \/><br \/>\n<br \/>\nHello, %username%.<\/p>\n<p>If you have just now asked the question, \"Hey, what does part 2 mean \u2014 and where is the first?!\" \u2014 you need to hurry up <noindex>here<\/noindex>.<\/p>\n<p>As for those who are already familiar with the first part \u2014 let's get straight to the point.<\/p>\n<p>Yes, and I know that for many, Friday has just begun \u2014 so here's a reason to prepare for the evening.<\/p>\n<p>Let's go.<br \/>\n<noindex><a rel=\"nofollow\" name=\"habracut\"><\/a><\/noindex><br \/>\nIn the beginning, I'll talk about the difficult journey of beer in Iceland.<\/p>\n<p>Prohibition in Iceland started even earlier than in the USA \u2014 in 1915. However, the situation didn't last long, as tough counter-sanctions followed: Spain, having lost the Icelandic wine market, stopped buying fish from Iceland in response. This lasted only six years, and starting in 1921, wine was removed from the list of banned products in Iceland. Beer, however, was not.<\/p>\n<p>It took another 14 years for the resilient Icelanders to regain the right to drink strong alcoholic beverages: in 1935, it became possible to drink wine, rum, whiskey, and everything else, but beer could only be consumed if it was not stronger than 2.25%. At that time, the country's leadership believed that regular beer contributed to the prosperity of debauchery, as it was more accessible than strong alcohol (of course, right?).<\/p>\n<p>The Icelanders found a completely simple and obvious solution, which made them even more likable to me after the 2016 European Championship: people simply diluted the allowed beer with the permissible strong alcohol. Naturally, the government always accommodates its citizens, and that's why in 1985, a convinced teetotaler and ulcer-ridden human rights minister (what irony!) managed to ban this simple trick.<\/p>\n<p>The consumption of beer in Iceland was finally permitted only on March 1, 1989, 74 years after the prohibition. It's clear that since then, March 1 has become Beer Day in Iceland: bars remain open until the early morning, and locals remember how they waited for three-quarters of a century for their favorite drink to return. By the way, you might want to add this date to your calendar as a perfectly valid reason to skip a pint.<\/p>\n<p>In the next part, I think I will write something interesting about Guinness\u2026<\/p>\n<p>But let's go back to where we left off, specifically \u2014 to the ingredients of beer.<\/p>\n<h4>Malt.<\/h4>\n<p>\nMalt is the second main ingredient in beer after water. And not just beer \u2014 malt serves as the basis for the production of many fermented beverages, including kvass, kulaga, maksymy, and whiskey. It is malt that provides food for yeast, thus determining both the strength and some taste characteristics. Honey, grainy, biscuit, nutty, chocolate, coffee, caramel, and bread \u2014 all these flavors come not from chemistry (thankfully or unfortunately) but from malt. What's more: no sensible brewer will add anything unnecessary that can be produced otherwise. Later you will see that this is not just about the flavors that can be derived from malt.<\/p>\n<p>Malt is a slightly germinated cereal: barley, rye, wheat, or oats. Barley malt is used <i>recommendations only<\/i>, if you drink wheat beer, then know: wheat malt in it is just an addition to barley. Similarly, oat malt is an addition to barley, it's used less frequently than wheat, but is utilized in the production of some stouts.<\/p>\n<p>Malt comes in two types: base malt \u2014 which gives the wort a lot of sugar for further fermentation but does not significantly affect the taste, and specialty malt \u2014 which is poor in fermentable sugars, yet imparts a distinct flavor to the beer. A significant portion of mass-produced beer varieties is made with several base malts.<\/p>\n<p>Grain raw materials intended for brewing require preliminary processing, which involves converting them into brewing malt. The process includes germinating cereal grains, drying, and cleaning off the shoots. Malt processing can take place either at a brewery or at a separate facility (malt house).<\/p>\n<p>The process of obtaining malt is divided into soaking and germinating seeds. During germination, chemical changes occur, creating new chemical substances. Various enzymes, of which there are many in germinating malt, play the main role in this. We will discuss some of them now. Get ready, %username%, it's going to be a mind-blowing experience.<\/p>\n<p>So, we have prepared sprouted malt. Let's move on to mashing \u2014 the process of making wort from malt. The malt is crushed and mixed with hot water, and the mash (the mixture of crushed cereal products) is gradually heated. The gradual increase in temperature is necessary because different enzymes in the malt act differently at various temperatures. The temperature pauses affect the flavor, strength, foamy texture, and density of the beer. Different stages activate different enzymes.<\/p>\n<p>Hydrolytic breakdown of starch (amylolysis) during mashing is catalyzed by the malt's amylases. In addition, the malt contains several enzymes from the groups of amyloglucosidases and transferases, which attack some starch breakdown products, but in terms of quantitative ratio, they are only of secondary importance during mashing.<\/p>\n<p>During mashing, the natural substrate is the starch contained in the malt. Like any natural starch, it is not a single chemical compound but a mixture that contains, depending on its source, 20 to 25% amylose and 75-80% amylopectin.<\/p>\n<p>The amylose molecule forms long, unbranched, spiral-wound chains composed of \u03b1-glucose molecules linked by glycosidic bonds at \u03b1-1,4 positions. The number of glucose molecules varies from 60 to 600. Amylose is soluble in water and is completely hydrolyzed to maltose by \u03b2-amylase from the malt.<\/p>\n<p>The amylopectin molecule consists of short branched chains. In addition to the bonds at \u03b1-1,4 positions, there are also \u03b1-1,6 bonds at branched points. There are about 3000 glucose units in the molecule \u2014 amylopectin is significantly larger than amylose. Amylopectin is insoluble in water without heat; upon heating, it forms a paste.<\/p>\n<p>Malt contains two amylases. One of them catalyzes the reaction that rapidly breaks down starch into dextrins, but relatively little maltose is produced \u2014 this amylase is called dextrinizing or \u03b1-amylase (\u03b1-1,4-glucan-4-glucanohydrolase). The second amylase produces a large amount of maltose \u2014 this is the saccharifying amylase or \u03b2-amylase (\u03b2-1,4-glucan-maltohydrolase).<\/p>\n<p>Dextrinizing \u03b1-amylase is a typical component of malt. \u03b1-Amylase is activated during malting. It catalyzes the breakdown of \u03b1-1,4 glycosidic bonds in the molecules of both starch components, i.e., amylose and amylopectin, unevenly breaking at the terminal bonds. This leads to liquefaction and dextrinization, resulting in a rapid decrease in the viscosity of the solution (liquefaction of the mash). In natural environments, such as in malt extracts and mashes, \u03b1-amylase has an optimum temperature of 70\u00b0C and is inactivated at 80\u00b0C. The optimal pH range is from 5 to 6, with a clear maximum on the pH curve. \u03b1-Amylase is very sensitive to increased acidity (it is acid-resistant): it is inactivated by oxidation at pH 3 at 0\u00b0C or at pH 4.2-4.3 at 20\u00b0C.<\/p>\n<p>Saccharifying \u03b2-amylase is found in barley, and its volume significantly increases during malting (germination). \u03b2-Amylase has a high capacity to catalyze the breakdown of starch to maltose. It does not liquefy insoluble native starch or even starch paste. From unbranched amylose chains, \u03b2-amylase cleaves secondary \u03b1-1,4 glycosidic bonds, specifically from the non-reducing (non-aldehyde) ends of the chains. Maltose is gradually cleaved one molecule at a time from individual chains. The breakdown of amylopectin also occurs; however, the enzyme attacks branched amylopectin molecules simultaneously at several spatial chains, specifically at the branching points where \u03b1-1,6 bonds are located, at which point the breakdown stops. The optimal temperature for \u03b2-amylase in malt extracts and mashes is between 60-65\u00b0C; it is inactivated at 75\u00b0C. The optimal pH range is 4.5-5, with some sources suggesting 4.65 at 40-50\u00b0C with a less pronounced maximum on the pH curve.<\/p>\n<p>Overall, amylases are often referred to as diastase; these enzymes are present in common types of malt and in special diastatic malt, forming a natural mixture of \u03b1- and \u03b2-amylase, where \u03b2-amylase quantitatively predominates over \u03b1-amylase. When both amylases act simultaneously, starch hydrolysis is much deeper than when each acts separately, resulting in 75-80% maltose production.<\/p>\n<p>The difference in the optimal temperature of \u03b1- and \u03b2-amylase is practically used to regulate the interaction between both enzymes by maintaining the activity of one enzyme at the expense of the other by selecting the correct temperature.<\/p>\n<p>In addition to starch breakdown, the hydrolysis of proteins is also critically important. This process, known as proteolysis, is catalyzed during mashing by enzymes from the peptidase or protease group (peptide hydrolases), which hydrolyze peptide bonds -CO-NH-. They are divided into endopeptidases, or proteases (peptide peptidases), and exopeptidases or peptidases (dipeptide hydrolases). In the mash, the substrates are residues of barley protein such as leukozein, edestine, hordelin, and glutenin, partially modified during malting (for example, coagulated during drying) and the products of their hydrolysis, namely albumoses, peptones, and polypeptides.<\/p>\n<p>Barley and malt contain one enzyme from the endopeptidase group (proteases) and at least two exopeptidases (peptidases). Their hydrolytic action complements each other. Barley and malt proteases are of the type similar to papain, which is very common in plants. Their optimal temperature ranges between 50-60\u00b0C, and the optimal pH varies from 4.6 to 4.9 depending on the substrate. Protease is relatively stable at high temperatures, which distinguishes it from peptidases. It is most stable in the isoelectric region, namely at a pH of 4.4 to 4.6. The enzyme's activity in an aqueous environment decreases after just 1 hour at 30\u00b0C; at 70\u00b0C, it completely degrades after 1 hour.<\/p>\n<p>Hydrolysis catalyzed by malt protease proceeds gradually. Several intermediate products have been isolated between proteins and polypeptides, with the most significant being peptide fragments\u2014peptones, also known as proteoses, albumoses, etc. These are the higher products of colloidal hydrolysis that exhibit typical properties of proteins. Peptones do not coagulate upon boiling. Solutions have an active surface, are viscous, and easily form foam when shaken\u2014this is extremely important in brewing!<\/p>\n<p>The final degree of protein hydrolysis catalyzed by malt protease is represented by polypeptides. They are only partially high molecular weight substances with colloidal properties. Typically, polypeptides form molecular solutions that diffuse easily. Generally, they do not react like proteins and are not precipitated by tannin. Polypeptides serve as substrates for peptidases, which complement the action of proteases.<\/p>\n<p>The peptidase complex in malt consists of two enzymes, but the presence of others is also permissible. Peptidases catalyze the cleavage of terminal amino acid residues from peptides, initially forming dipeptides and finally amino acids. Peptidases are characterized by substrate specificity. Some of them are dipeptidases, which hydrolyze only dipeptides, and polypeptidases, which hydrolyze higher peptides containing at least three amino acids in their molecule. The group of peptidases includes amino-polypeptidases, whose activity is determined by the presence of a free amino group, and carboxypeptidases, which require a free carboxyl group. All malt peptidases have an optimal pH in the weakly alkaline range between pH 7 and 8 and an optimal temperature of around 40\u00b0C. At pH 6, where proteolysis occurs in germinating barley, the activity of peptidases is pronounced, while at pH 4.5-5.0 (the optimum for proteases), peptidases are inactivated. In aqueous solutions, peptidase activity decreases at 50\u00b0C, and at 60\u00b0C, peptidases are rapidly inactivated.<\/p>\n<p>When mashing, enzymes that catalyze the hydrolysis of complex phosphoric acid esters and phospholipids of cell membranes play a significant role. The cleavage of phosphoric acid is technically very important due to its direct influence on the acidity and buffering system of brewing intermediates and beer, while the fatty acids formed from phospholipids create complex esters during fermentation, contributing to various aromas. The natural substrate for malt phosphoesterases is the complex esters of phosphoric acid, of which phytic acid predominates in malt. This is a mixture of calcium and magnesium salts of phytic acid, which is the hexaphosphate complex ester of inositol. In phosphatidates, phosphorus is linked as a complex ester with glycerin, while nucleotides contain a phosphoric ester of ribose associated with a pyrimidine or purine base.<\/p>\n<p>The most important malt phosphoesterase is phytase (mesoinositol hexakisphosphate phosphohydrolase). It is very active. Phytase gradually cleaves phosphoric acid from phytic acid. In doing so, various phosphoric complex esters of inositol are formed, which eventually yield inositol and inorganic phosphate. Alongside phytase, other enzymes have also been described, such as sugar phosphorilase, nucleotide pyrophosphatase, glycerophosphatase, and pyrophosphatase. The optimal pH range for malt phosphatases is relatively narrow \u2014 from 5 to 5.5. They are differently sensitive to high temperatures. The optimal temperature range of 40-50\u00b0C is very close to the temperature range of peptidases (proteases).<\/p>\n<p>The formation of enzymes is greatly influenced by oxygen \u2014 without it, the grain simply does not sprout, and light \u2014 it destroys some enzymes, particularly diastase, which is why malting rooms (malt houses) are designed with minimal light access.<\/p>\n<p>Until the 19th century, it was believed that only malt, which did not sprout until the emergence of a shoot, was suitable. In the 19th century, it was proven that malt, in which the shoot reached a relatively large size (long malt, Ger. Langmalz), contains significantly greater amounts of diastase, provided that malting was carried out at the lowest possible temperature.<\/p>\n<p>Among other things, malt is also used for making what is known as malt extract. Malt extract is a concentrated or dehydrated wort, brewed from crushed barley, rye, corn, wheat, and other cereal grains. The wort is gently evaporated under vacuum at temperatures of 45 to 60\u00b0C to a syrup-like consistency, clarified, freed from astringent compounds through separation and centrifugation. In beer production, malt extract is used quite rarely, as it does not allow for experimentation with a variety of flavors and colors.<\/p>\n<p>A variety of flavors can be obtained very simply. Depending on the degree of drying, different types of malt can be produced \u2014 light, dark, and black. To achieve dark and especially caramel varieties, the malt is roasted. The stronger the malt is roasted, the more sugars caramelize in it. The caramel flavor is imparted to the beer by malt that essentially contains real caramel inside: after steaming and drying, the starch present in the malt turns into a caramelized solid mass. This will contribute characteristic notes to the beer \u2014 and similarly, a \"burnt taste\" can be added using actually charred malt. The Germans also have \"smoked beer\" \u2014 rauchbier, which is made using fire-smoked green malt: the heat and smoke from the burning fuel dry and simultaneously smoke the germinated grain. Moreover, the taste and aroma of the future beer directly depend on the type of fuel used to smoke the malt. At the \"Schlenkerla\" brewery (which, by the way, is over 600 years old), aged beech wood is used for this purpose, which gives this variety its specific smoky profile \u2014 well, the efforts of these Bavarian brewers are understandable: it is necessary to find some original variants within the narrow confines of the German beer purity law, but we will discuss these \"confines\" and more after we cover all the ingredients of beer.<\/p>\n<p>It should also be noted that it is impossible to brew beer using only dark malts: roasting destroys the enzymes necessary for saccharification of the wort. Therefore, any beer, even the darkest rauchbier, will contain light malt as well.<\/p>\n<p>Thus, by using various types of malt, a whole set of different substances already enters the beer before the fermentation process, the most important of which are:<\/p>\n<ul>\n<li>Sugars (sucrose, glucose, maltose)<\/li>\n<li>Amino acids and peptones<\/li>\n<li>Fatty acids<\/li>\n<li>Phosphoric acid (Always Coca-Cola! Spare me, spare me!)<\/li>\n<li>Products of incomplete combustion during the drying of all the aforementioned rich composition<\/li>\n<\/ul>\n<p>\nWith sugars, everything is clear \u2014 this is the future food for yeast, as well as the sweet taste of beer (it was balanced before with herbs, and later with hops, adding bitterness), and everything is clear with the products of incomplete combustion \u2014 this provides a darker color, smoky and caramel taste and aroma. I have talked about the importance of peptones and foam \u2014 but I won't tire of repeating it. We'll come back to fatty acids when we talk about yeast and the emergence of fruity aromas.<\/p>\n<p>By the way, speaking of peptones, proteins and cell death \u2014 something reminded me of a story I read on one of the thematic public pages. It is under a spoiler for some reasons.<br \/>\n<b class=\"spoiler_title\">Not for children, women and the faint-hearted!<\/b>Almost 10 years ago, an interesting Scottish brewery BrewDog released an incredibly strong beer \u2014 a staggering 55%, which for a long time was the strongest beer in the world. A very small part of this batch was packaged in a protein (specifically a small mammal, not a protein) and other furry animals. A bottle of this beer called The End of History, designed with taxidermied small mammals (it is said the bodies were simply found on roads), cost around $750.<br \/>\n<img decoding=\"async\" alt=\"Beer through the eyes of a chemist. Part 2\" src=\"\/wp-content\/uploads\/2019\/05\/3e4081f88edb0bc6c24445596b79b58c.jpeg\" style=\"display:block;margin: 0 auto;\" \/><br \/>\n<br \/>\nWe'll conclude on malt by just mentioning that domestic malt is quite good \u2014 and is therefore actively used alongside imported malt.<\/p>\n<h4>Yeast.<\/h4>\n<p>\nAnother absolutely essential component of beer is, in fact, yeast. Well, where would we be without them, right?<\/p>\n<p>Brewer's yeast is a microorganism that carries out fermentation. In turn, fermentation is a biochemical process based on the redox transformations of organic compounds in anaerobic conditions, meaning without access to oxygen. During fermentation, the substrate \u2014 in our case, sugar \u2014 is not fully oxidized, which makes fermentation energetically inefficient. Depending on the type of fermentation, the fermentation of one glucose molecule yields between 0.3 and 3.5 molecules of ATP (adenosine triphosphate), while aerobic respiration (that is, with oxygen consumption) involving complete oxidation of the substrate yields 38 molecules of ATP. Due to the low energy output, fermentative microorganisms are forced to process enormous amounts of substrate. And this, of course, plays to our advantage!<\/p>\n<p>Besides alcoholic fermentation, where monosaccharides and disaccharides are converted into ethanol and carbon dioxide, there is also lactic acid fermentation (resulting in lactic acid), propionic acid fermentation (leading to lactic and acetic acids), formic acid fermentation (producing formic acid with variations), butyric acid fermentation (yielding butyric and acetic acids), and homoacetate fermentation (resulting only in acetic acid). It is unlikely that a beer enthusiast would want anything other than the authentic alcoholic fermentation to occur \u2014 I don\u2019t think anyone would enjoy drinking sour beer that smells like rancid oil or spoiled cheese. Thus, the proportion of 'foreign fermentation' is strictly controlled, particularly by maintaining the purity of the yeast. <\/p>\n<p>Yeast production is a vast industry: entire laboratories, either independent or established by breweries, are dedicated to developing strains of brewer's yeast with specific characteristics. The recipe for yeast often remains a closely guarded secret by the brewer. It is said that among the northern European peoples, there was a tradition of passing down a special brewing stick from generation to generation. Without stirring the brew with this stick, the beer would not turn out right, so the stick was considered somewhat magical and was kept with great care. Naturally, back then, they did not know about yeast and did not understand the true role of the stick, but even then, the value of this mystery was recognized.<\/p>\n<p>However, there are exceptions to every rule. For example:<\/p>\n<ul>\n<li>In Belgium, lambics are brewed \u2014 this is a beer that ferments spontaneously, thanks to microorganisms that enter the wort from the air. It is believed that true lambics can only be produced in certain regions of Belgium, and it's clear that the fermentation there is so mixed and complex that even the devil would struggle. However, frankly: lambics are an acquired taste, and they definitely won't suit those who believe that beer shouldn't be sour.<\/li>\n<li>The American brewery Rogue Ales brewed an ale based on yeast that the head brewer carefully cultivated in his own beard.<\/li>\n<li>His Australian colleague from the 7 Cent brewery went even further and grew wild yeast in his belly button, before releasing a beer based on it.<\/li>\n<li>The Polish brewery The Order of Yoni brewed beer a few years ago using yeast derived from women. Well, not from women directly\u2026 from yeast taken from women. No women were harmed in the process\u2026 So, you get the idea\u2026<\/li>\n<\/ul>\n<p>\nDuring fermentation, brewer's yeast not only consumes sugars and produces what is expected, but also performs a large number of other chemical processes simultaneously. In particular, esterification processes occur \u2014 the formation of complex esters: after all, there is alcohol, fatty acids (remember the malt?) \u2014 they can be used to create many interesting things! This can range from green apple (found in some American lagers) to banana (typical for German wheat beer), and pear, and butter. This reminds me of school and various esters that smelled so enticing. But not all of them. Whether the drink will have a fruity aroma or a subtle scent of a mix of moonshine and solvent depends on the concentration of complex esters, which in turn depends on various factors: fermentation temperature, extractiveness of the wort, yeast strain, and the amount of oxygen that entered the wort. We'll discuss this when we get to the brewing technology. <\/p>\n<p>By the way, yeast also influences the taste \u2014 we will remember this when we talk about hops.<\/p>\n<p>And now, since we've become acquainted with yeast, I can reveal the one true way to categorize beer. And no, %username%, it's not 'light' and 'dark,' because neither light nor dark really exists, just as there are no 100% blondes and 100% brunettes. It is the division into ale and lager.<\/p>\n<p>Strictly speaking, there are two types of fermentation in brewers' eyes: top fermentation (yeast rises to the top of the wort) \u2014 this is how ale is produced, and bottom fermentation (yeast sinks to the bottom) \u2014 this is how lager is made. It's easy to remember:<\/p>\n<ul>\n<li>Ale \u2192 yeast ferments high \u2192 fermentation temperature is high (around +15 to +24 \u00b0C) \u2192 consumption temperature is high (from +7 to +16 \u00b0C).<\/li>\n<li>Lager \u2192 yeast works low \u2192 fermentation temperature is low (around +7 to +10 \u00b0C) \u2192 consumption temperature is low (from +1 to +7 \u00b0C).<\/li>\n<\/ul>\n<p>\nAle is the oldest type of beer; it was brewed by the very first brewers hundreds of years ago. Most ales today are characterized by: higher density, more complex flavor, often fruity aroma, and generally darker color (compared to lagers). An important advantage of ales is the relatively simple and inexpensive production process, not requiring additional cooling equipment as is the case with lagers, which is why all craft breweries can offer some form of ale.<\/p>\n<p>Lager appeared later: its production was more or less adequately mastered only in the 15th century, and it began to gain serious momentum only in the second half of the 19th century. Modern lagers are known for their more straightforward and often hoppier flavor and aroma, as well as typically lighter color (although there are black lagers) and lower alcohol content. A fundamental difference from ales is that at the final stage of production, the lager is transferred to special containers and matures there for several weeks or even months at near-zero temperatures \u2014 this process is called lagering. Lager types have a longer shelf life. Due to the ease of maintaining quality stability and a long shelf life, lager is the most popular type of beer in the world: almost all large breweries produce lagers. However, since the production requires a more complex technology (let's remember about lagering) and the presence of special frost-resistant yeast \u2014 therefore, the presence of original (truly original, not rebranded) lagers in the list of offered types at any craft brewery signifies its status and the experience of its brewers.<\/p>\n<p>Many (including myself) believe that ales are a more \"correct\" type of beer compared to lagers. Ales are more complex in terms of aromas and flavors; they are often richer and more diverse. On the other hand, lagers are simpler to perceive, often more refreshing, and generally less strong. A lager differs from an ale in that it lacks the distinct flavor and aroma of yeast, which are important and sometimes essential characteristics of ales.<\/p>\n<p>Well, we've sorted that out. Right? No, that's not correct \u2014 there are instances when beer represents a hybrid of lager and ale. For example, German K\u00f6lsch is top-fermented beer (that is, ale) that matures at low temperatures (like a lager). As a result of this hybrid production scheme, the drink possesses characteristics of both types of beer: clarity, lightness, and freshness coexist with barely noticeable fruity notes in the taste and a fleeting yet pleasant sweetness. And a little hint of hops at the end.<\/p>\n<p>In fact, if you, %username%, suddenly feel you've become knowledgeable about beer classification, here's a final note for you:<br \/>\n<img decoding=\"async\" alt=\"Beer through the eyes of a chemist. Part 2\" src=\"\/wp-content\/uploads\/2019\/05\/8064a64e8ce4db61e18ce690a6847f76.jpeg\" style=\"display:block;margin: 0 auto;\" \/><br \/>\n<br \/>\nLet's summarize about yeast: overall \u2014 the longer the yeast works, the more the taste and character of the beer can change. This is especially true for ales, which have a higher concentration of substances affecting taste and aroma. For this reason, some types of ales imply bottle conditioning: the beer is already bottled and sitting on the store shelf, but the fermentation process is still occurring inside. By buying a couple of bottles of such beer and drinking them at different times, you can notice a significant difference. At the same time, pasteurization deprives the beer of some flavor characteristics as it eliminates the presence of live yeast in the drink. This is why many people cherish unfiltered beer: even after pasteurization, the remnants of the yeast culture can enhance the drink's flavor. The sediment visible at the bottom of a container with unfiltered beer is indeed the remains of the yeast.<\/p>\n<p>But all of this will come later; for now, we have to list a few more optional components of beer.<\/p>\n<p>This will be covered in the next part.<br \/>\n<br \/>Source: habr.com<\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>\u041f\u0440\u0438\u0432\u0435\u0442, %username%. \u0415\u0441\u043b\u0438 \u0443 \u0442\u0435\u0431\u044f \u043f\u0440\u044f\u043c\u043e \u0441\u0435\u0439\u0447\u0430\u0441 \u0432\u043e\u0437\u043d\u0438\u043a \u0432\u043e\u043f\u0440\u043e\u0441: \u00ab\u042d\u0439, \u0447\u0442\u043e \u0437\u043d\u0430\u0447\u0438\u0442 \u0447\u0430\u0441\u0442\u044c 2 \u2014 \u0430 \u0433\u0434\u0435 \u043f\u0435\u0440\u0432\u0430\u044f?!\u00bb \u2014 \u0441\u0440\u043e\u0447\u043d\u043e \u0438\u0434\u0442\u0438 \u0441\u044e\u0434\u0430. \u041d\u0443 \u0430 \u0434\u043b\u044f \u0442\u0435\u0445, \u043a\u0442\u043e \u0443\u0436\u0435 \u0437\u043d\u0430\u043a\u043e\u043c \u0441 \u043f\u0435\u0440\u0432\u043e\u0439 \u0447\u0430\u0441\u0442\u044c\u044e \u2014 \u043f\u0435\u0440\u0435\u0445\u043e\u0434\u0438\u043c \u043d\u0435\u043f\u043e\u0441\u0440\u0435\u0434\u0441\u0442\u0432\u0435\u043d\u043d\u043e \u043a \u0434\u0435\u043b\u0443. \u0414\u0430, \u0438 \u044f \u0437\u043d\u0430\u044e, \u0447\u0442\u043e \u0434\u043b\u044f \u043c\u043d\u043e\u0433\u0438\u0445 \u043f\u044f\u0442\u043d\u0438\u0446\u0430 \u0442\u043e\u043b\u044c\u043a\u043e \u043d\u0430\u0447\u0430\u043b\u0430\u0441\u044c \u2014 \u043d\u0443 \u0432\u043e\u0442 \u0438 \u043f\u043e\u0432\u043e\u0434 \u043f\u043e\u0434\u0433\u043e\u0442\u043e\u0432\u0438\u0442\u044c\u0441\u044f \u043a \u0432\u0435\u0447\u0435\u0440\u0443. [&hellip;]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":25912,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[702],"tags":[],"class_list":["post-34389","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 5.0.2 - aioseo.com -->\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<meta name=\"author\" content=\"Yuri Gagarin\"\/>\n\t<link rel=\"canonical\" href=\"https:\/\/prohoster.info\/en\/blog\/news\/o-pive-glazami-himika-chast-2\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 5.0.2\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"\ud83e\udd47\u041e \u043f\u0438\u0432\u0435 \u0433\u043b\u0430\u0437\u0430\u043c\u0438 \u0445\u0438\u043c\u0438\u043a\u0430. \u0427\u0430\u0441\u0442\u044c 2 | ProHoster\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/prohoster.info\/en\/blog\/news\/o-pive-glazami-himika-chast-2\" \/>\n\t\t<meta property=\"og:image\" content=\"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg\" \/>\n\t\t<meta property=\"og:image:secure_url\" content=\"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg\" \/>\n\t\t<meta property=\"og:image:width\" content=\"350\" \/>\n\t\t<meta property=\"og:image:height\" content=\"350\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2019-10-31T18:58:03+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2019-10-31T18:58:03+00:00\" \/>\n\t\t<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/prohoster\" \/>\n\t\t<meta property=\"article:author\" content=\"https:\/\/www.facebook.com\/prohoster\" \/>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"\ud83e\udd47On Beer Through the Eyes of a Chemist. 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