Craft brewery Mlinarica
our beer production process
01
Water preparation and mashing
Today’s modern technology has allowed us to easily adjust water to any style of beer. In our brewery, by reverse osmosis and UV lamp, we remove all cations, anions, and other minerals from the water. That is how we obtain perfectly clean and demineralized water, which we adjust for each beer separately.
By adjusting the water, we can greatly influence the flavors and aromas of the beer.
Certain minerals in water are important for the growth and development of yeast, the utilization of hop and its aromas and bitterness, and for greater utilization of barley malt and the taste it gives us.
Water preparation is an important, but not the most important part of beer preparation, so the next time you see an ad for „spring water“ used for beer, you will have the awareness that that water is most likely adjusted by reverse osmosis.
After we have adjusted the water, we start with mashing.
Mashing is a process in which ground malt is at different temperatures soaked in warm water. The most common temperature is between 63 °C and 69 °C. The duration of the process is 60 minutes.
During the mashing process, the starch found in barley malt is converted into sugars. We get the sweetened water which we call wort. The sugars we get from malt will later bind to the yeast and produce alcohol and carbon dioxide (CO2).
Besides the barley malt, we can also use wheat malt or rye malt, or even oat or barley flakes, basically everything that contains starch, that means even potatoes.
In short, in the beer mashing process, the water gets on the sweetness from the barley malt.
02
Draining the wort and boiling
After the end of mashing, we want to separate the wort (sweetened water) from the malt. We transfer the whole mixture to a pot in which the draining process will take place, where we separate the wort from the malt. Malt absorbs approximately 1-1.2 L of water. During the draining process, the malt must be sparged with warm water because it has already absorbed some of the water.
In our brewery, we do the draining by gravity, which means that the kettle for draining must be at a higher level, while the lauter tun (a vessel for pure wort) is just below the draining vessel.
The drained wort is then transferred to a brewing kettle, to which hops are also added.
Once the wort boils, we add the first hops that give the most bitterness to the beer. Longer boiling releases more alpha acids (bitter substances from hops), and we achieve a balance in regards to the sweetness
of wort. Boiling lasts for 60 minutes, and as it goes towards its end, we add hops for aroma and taste.
A good part of aroma and taste will be obtained when the hops are added in the last 15 minutes of boiling, and most of all once the boiling is over.
In the boiling process, one part of the wort (around 5%) evaporates, so this must also be taken into account in the production process, as well as when making a new recipe.
03
Whirlpool and cooling
The last part of the boiling process is now ready to take place. We can get the most of the aromas from the hops on the warm side of the brewing,
so we can add some hops in the whirlpool known as „Whirlpool hopping“, to achieve the desired and better flavour.
There are different technological processes of the whirlpool. In our brewery, we are doing the whirlpool in a separate kettle, while some breweries make a whirlpool in the same kettle in which they brew the beer. The whirlpool lasts about 20 minutes.
After 20 minutes, we begin with the wort cooling process. The wort is cooled through a heat exchanger. In the first part of the process, we cool the wort with cold water, and in the second with ice water, at -4 °C
(a combination of water and glycol). After the work with the heat exchanger finishes, the wort immediately goes directly through the hoses into the tank.
The wort is cooled from the temperature of 99 °C to 11 °C, or 18 °C, depending on which type of beer we produce. The hoses through which the wort goes to the fermenter are connected directly to the heat exchanger. Cooling takes between 30 and 40 minutes.
04
Adding the yeast and fermentation
Once the wort is cooled to the desired temperature, it is time to add the yeast. The wort, which is at that moment full of sugar, is the main source of food for the yeast. The moment in which the yeast begins to eat the sugars is the moment in which the fermentation has begun. Three to four days after, depending on the type of beer, the main part of fermentation (or „high kräusen“) takes place.
Fermentation lasts from 5 to 15 days and its duration is determined by the type of beer that ferments.
During fermentation, yeast feeds on sugars. By-products of these activities are alcohol and CO2. At one point, we close the airlock, and the CO2 that is created during fermentation remains in the tank, in that way naturally carbonating the beer.
Probably some have already heard that yeast is the one that makes the beer, which is and is not true. It is said that the brewer makes only the „preparation“, and the yeast does the rest, but also the brewer needs to use measuring instruments and tasting skills to estimate when the beer is finished with fermentation and ready for aging.
05
Aging
After fermentation, the time has come for a bit of patience, which means: aging.
Here every beer has its own rules. The aging can last 10 days (pale ale) or 40-80 days (Czech-style lager, Vienna lager, or Black widow).
With lagers, the aging time is very important and there is a huge difference in taste if the beer ages for 40, 50, 60 or 80 days.
During aging, the beer is carbonated. The yeast settles to the bottom of the tank, the beer gets clearer and the flavours take shape. If the beer does not age long enough, it can be hazy (this does not necessarily happen if the beer contains wheat malt, oats or some specific yeast strains), it can have a lower carbonation level and the flavours may be a little bit „mixed“. So, in this case, the old saying „all good things come to him who waits“ really turns out to be true.
Aging usually takes place at low temperatures, between 0 °C and 1 °C.
Some beers from Mlinarica brewery age in wooded barrels, and aging can take up to a year.
After aging the beer, the brewer must make one last sacrifice and one more time use his tasting skills, to check the taste and the smell of the beer. After that, you can start safely and carefree enjoying our beer.
