How to make beer at home
Before going to the guide for preparing beer at home, it is good to know that since 1995 (Legislative Decree No. 504 of 26/10/95) in Italy it is possible to produce beer in the home, provided it is not sold. The law does not set quantitative limits but the marketing ban. This means that the quantities produced can only be for self-consumption. Now we will see how to make beer at home and all the steps necessary to get to this interesting goal.
Meanwhile, let’s start from the raw material. These are essentially cereals, and in particular barley, which undergo different malting processes according to the type of product to be made, and are then ready to finish off in the process leading to the production of beer.
To do this, it is necessary to extract practically the sugars contained in the grains, obtaining, finally, a must.
After the yeast inoculation, inside the must, begins a phase more purely of management and control of the times and temperatures that in the various stages of fermentation will guide the yeasts themselves in their work of transformation of those sugars of the must into different by-products of its metabolism, namely alcohol, carbon dioxide and esters (aromas).
The first phase is that of milling. So before reaching the most appropriate phase of mashing, it is necessary to physically break the grains (of cereals or of barley) to allow the water to take in solution these starches, thus allowing the rest of the process. The cereals must then be broken and ground. This is one of the phases on which many characters of the future beer depend. in fact from the grain of the fragments depend some indices such as the efficiency of mashing and the overall efficiency, which express the amount of sugars extracted in relation to the total of those contained potentially in the grains.
At this point, ground the cereals, you go to the mashing. In mixing these cereals with water, starches are allowed to go into solution. At this point we start the real process of mashing that is nothing but the reduction of starches to simpler sugars (and therefore fermentable). In general it is barley that already contains a better enzymatic composition for the mashing process that must take place at a certain temperature.
Basically it is about mixing our ground cereal with hot water so that inside the grain the enzymes turn the starches into sugars.
Before this phase only 15-20% of malt is soluble, thanks to the mash we reach a percentage of 65-80%.
There are three main methods for carrying out the mashing:
– infusion (also called multistep infusion): our mixture of water and cereals is brought to different temperatures and with different time intervals by direct heating of the mixture itself (the classic pot on the fire). This is probably the most used by homebrewers;
– English infusion: in a container that has a low heat dispersion, the cereal is placed and, at various times, water is added at certain temperatures so as to bring the temperature of the mixture and the grains / water ratio to the desired quota. Normally this type of infusion applies to recipes that do not require the use of non-malted cereals;
– decoction: part of the mixture of water and grains is placed in a secondary pot and brought to a boil. It is then combined with the main mixture, raising its temperature. Obviously, to determine the amount of mixture that must be taken and brought to a boil to reach the desired temperature, it is necessary to perform calculations in advance.
The main purpose of mashing is to break down proteins and starches that have not been transformed during the malting process. This work is done by various groups of enzymes that degrade different substrates if activated at certain temperatures.
With light malts this enzymatic degradation begins with the acid rest, where phytase breaks phytate into calcium or magnesium phosphate and phytic acid. This helps the acidification of the must when the water has a low calcium content and the very toasted grains are not included in the recipe. This pause takes place at temperatures between 35 ° C and 49 ° C. Another group of enzymes active in this range are b-glucanases, which break the hemicellulose and gums in the cell walls of unmodified malts. Some additions, especially rice, have high levels of these substances, and problems such as stuccoed must be found if they are not degraded into simpler substances by b-glucanases.
For many malts, the mash begins with the protein rest (protein break), which usually occurs at temperatures between 46 ° C and 52 ° C. This process begins with proteases, which break down the heavy molecules of proteins into smaller fractions such as polypeptides. These polypeptides are also degraded, by peptide enzymes, into peptides and amino acids, which are essential for the proper growth of yeast. Proteins with a molecular weight of 17,000 up to 150,000 must be reduced to polypeptides weighing 500-12,000 for good foam formation, and some are further reduced to 400-1500 for good yeast nutrition.
The final enzymatic process converts the starches into dextrins and fermentable sugars. The starches must first be gelatinized, and this occurs at temperatures of 54-65 ° C for the malt. Gelatinization for untreated grains, such as corn, occurs at higher temperatures, so these beans must be boiled or made into flakes before adding them to the must. The breakdown of starches is carried forward by the combined action of the enzymes a-amylase and b-amylase during the saccharification pause. These enzymes break the bonds 1-6 of starches reducing the complexity of the molecules. The diastatic enzymes, or amylases, work in tandem, with the enzymes b in dividing the maltose units from the reducing head and breaking the bonds 1-4 randomly. Temperatures below 65 ° C favor b-amylase, producing a more fermentable must, while temperatures above 68 ° C favor amylase, producing a more dextrinic must. The simplest sugar produced is a monosaccharide, that is, it has only a sugary base in its molecule. Monosaccharides in the must include glucose, fructose, mannose and galactose. The disaccharides are made of two combined monosaccharides, and include maltose, isomaltose, sucrose, mellibose and lactose. Trisaccharides include maltotriose, which is slowly fermentable and supports yeast during lagerization. Oligosaccharides, constructed from chains of glucose (different monosaccharides), are soluble in water and are called dextrins. The relative concentration of these sugars is determined by the type of malt and whether b-amylase or a-amylase has been favored.
After completing this phase, many brewers finish by raising the temperature of the must to 75 ° C for several minutes. This ensures the deactivation of amylase and the conversion of dextrins into fermentable sugars. It also reduces the viscosity of the must, facilitating filtering. However, they all agree that the best extraction conditions occur at these temperatures.
Of course, one technique is not the same but affects the “type” of beer we will get.
Once this sugar must is obtained, the liquid part must be separated from the solid part. It is therefore necessary to filter it gently. It is an operation that, if slow and accurate, can have positive effects on the quality of the must and its clarity. Depending on the equipment and production methods, an additional step (called sparging) or washing of the grains may be necessary. this is based on the fact that, with the classical dilutions, it is not possible to extract the whole quantity of sugars from the grains in a single filtration; for this reason it is necessary to add to these a further quantity of water to make these sugars still trapped in the threshers more easily and take them together with the first must to reach the designated values.
At this point we arrive at the boiling phase. This is the operation that allows you to sterilize the must and make it more concentrated, allowing an evaporation of a part of water. Simultaneously with the boiling of the must in the strict sense, one of the most important actions performed at this stage is hopping. The addition of this ingredient while the must is boiling is essential: the boiling allows the compounds contained in the hops to dissolve and be transformed, activating chemical processes that cause the formation of compounds responsible for the bitter taste. Hopping is an operation that balances the bitter taste necessary to counteract the sweet aromas deriving from cereals. Obviously the lower the boiling time of the hops with the must, the less bitter we will extract. To do this we recommend gradually adding the hop to the final minutes of boiling to pass from the typically bitter flavor to a more aromatic one. This process is obviously of craftsmanship of master brewers and characterizes the various types of beer we can get.
After this process has been performed, before adding the yeast, cooling must be done (otherwise we would devitalize the yeasts). It is a process in which the hygienic precautions must be considerable, as long as the must is sterilized the sterilization is assured, then as it cools it can intervene various contaminations. in fact, when the must is cooled to around 15 – 20 ° C, yeasts and bacteria are introduced into the working range, both in the air and on tools and objects that come into contact with it.
Before the inoculation phase we must be sure of the sanification of the container (fermenter) that will house the cooled must. In this phase it is necessary to oxygenate the mass (or mechanical stirring or by falling) making it beat on the bottom of the fermenter and so make it include oxygen, necessary for the first phase of multiplication of the yeast, which will be inserted at the end of transfer. The fermenter must be hermetically sealed, with its cap, leaving a bubbler for the escape of carbon dioxide but do not allow the entry of air from the outside.
The fermentation phase begins in a period of time ranging from a few hours to a few days (depending on the type of yeasts). At the beginning (first week) there is the tumultuous phase (or primary fermentation) with transformation of fermentable sugars into carbon dioxide, as well as alcohol and flavorings. Here it is essential to manage the fermentation temperature and control it, which determines the qualitative and quantitative performance of the yeast’s work. Once this phase has passed, the bubbling takes on an increasingly mild cadence, as fermentation becomes secondary. This period (always determined by the type of yeast) varies from a couple of weeks to a couple of months.
After this period we are ready for packaging. You can move on to this operation if you notice that the density of the fermented must no longer changes despite the passing of the days. Here too the containers (bottles or any drums) must be absolutely free of any bacterial impurities or other organisms that would damage the beer.
It is often advisable to transfer the must to another clean fermenter to exclude its bottom, where used yeast and various proteins have been deposited.
Before packing, the decanting may be necessary, above all because in the bottle or in the stem one wants to recreate an appropriate gassing thanks to a second fermentation, called refermentation. The refermentation is obtained by adding sugar, which will be metabolized by the yeasts that are inevitably suspended in the beer and which will produce an additional amount of carbon dioxide. For this reason, once bottles and barrels have been tapped, a suitable temperature must be assured, very close to that of the first fermentation. The refermentation time is normally a couple of weeks but a beer maturation aft which lasts for several weeks is needed. This time varies from a few weeks for very light and / or very hopped beers to many weeks for more complex and more alcoholic beers; this allows the yeasts to remove even some imperfections.