Beer is the third most popular drink after water and tea.
It is produced by brewering and fermentation of starches, mainly derived from cereal grains-the most common of which is malted barley, although wheat,maize/corn and rice are also widely used.
Production of Beer
The process of making beer is known as brewing. The purpose of brewing is convert the starch source into a sugary liquid called wort and to convert the wort into alcoholic beverage known as beer in fermentation process effected by yeast.
Barley selected for use in the malting industry must meet special quality specifications. Accepted malting barley varieties have to modify evenly and produce a finished malt whose properties lie within the brewer’s specifications. The malt quality of a given barley variety is determined by its genetic background and the physical conditions during growth, harvest and storage.
When storage at very low temperature and low moisture content barley may keep its vitality for centuries should be kept at a moisture content of below 12% and at temperatures below 12 degree Celsius.
Fungal contamination during storage: barley with a moisture content of above 14% may be attacked by fungi during storage especially by species Aspergillus, Fusarium and Penicillium. Secondary metabolites of these fungi cause gushing.
From Barley to Malt
Steeping and Germination
From the silos the barley is transported to the steeping and germination plant. During the steeping process the moisture level in the barley reaches 45% over a period of 2days. At the completion of steeping, the germinating grain, referred to ‘green malt’ is transferred to the germination boxes and allowed to germinate for 5 days.
The germinated green malt is dried in the kilning with heated air which is blown through the layer of green malt for 24 hours to produce about 285 tons of finished malt from original 330 tons of cleaned barley. The moisture content after kilning is 4%.
Mashing are performed at pH 5.5 at which most malt-derived enzymes exhibit high activity.
Conditions include a controlled step wise increase in temperature that preferentially favours one enzyme over the other, eventually degrading cell walls, proteins and starch. Since the enzymes which degrade cell walls and proteins are heat labile, it is important for their function that mashing begins at the low temperature. Mashing at 65 degree celcius or higher is geared to control conversion of gelatinized starch into fermentable sugars using malt-derived starch degrading enzymes.
Mashing enzymes include (1-3,1-4)-beta-glucanase and xylanase for cell wall degradation, endo-peptides and carboxypeptodase for protein degradation; and amylases, limit dextrinase for starch degradation.
A good beer needs a good aroma and acceptable palate and a great deal of that flavour in beer is provided by hops.
The lupulin glands of the female flower cones of the hop plant provide the different bitter substances which are the basis for beer bittering. Hop cones or hop extracts are added during the wort boiling where the largely insoluble a-acids from hops are isomerized to the more soluble iso-a-acids. Hops also contain beta-acids which are claimed to add bitterness to beer, after oxidation.
Bitter substances 19%, oils 0.5%, protein 20%, polyphenols 4% and minerals 8% in the hops.
After fermentation temperature is lowered and 1-the beer is maturated for a period during which the off-flavour component diacetyl is assimilated by yeast cells. 2-mature beer is chilled to temperature of -2 degree of Celcius for a couple days. By doing so the colloidal stability of beer is improved due to precipitation of protein –tannin complexes which are soluble at low temperature. 3- the beer is ready for final stabilization which removes amounts of proteinaccous matter and/or tannins, and subsequent filtration. The bright beer is obtained and adjusted to the correct carbon dioxide content, is ready for bottling.
When the residual yeast cells have been removed it is importance that oxygen uptake is reduced since oxygen will damage the flavour of stability of beer.
Finished beer is bottled, canned or filled into kegs. It may be tunnel pasteurised, flash pasteurised or aseptically bottled. In either case the beer must appear fresh, bright and without faults to the customer.
The beer must be free from m/o to ensure biological stability.
The ethanol content must obey fiscal rules but also major importance for the flavour of the beer.
Visually the finished beer must form a nice foam on pouring , it must have an attractive color.
Foam and Flavour
An importance aspect of beer quality is the formation of stable head of foam when beer is poured.
The proteinaccous compounds in beer are involved in foam formation.
The main flavour characteristics are the bitter taste derived from hops.
Malting Mashing Filtration Wort boiling
7 Temmuz 2006 CUMA
Sayı : 26221
Tarım ve Köyişleri Bakanlığından:
TÜRK GIDA KODEKSİ
(TEBLİĞ NO: 2006/33)
MADDE 1 – (1) Bu Tebliğin amacı, biranın tekniğine uygun ve hijyenik şekilde üretim, hazırlama, işleme, muhafaza, depolama, taşıma ve pazarlamasını sağlamak üzere özelliklerini belirlemektir.
MADDE 2 – (1) Bu Tebliğ birayı kapsar. Malt içeceğini kapsamaz.
MADDE 3 – (1) Bu Tebliğ, 16/11/1997 tarihli ve 23172 mükerrer sayılı Resmi Gazete’de yayımlanan “Türk Gıda Kodeksi Yönetmeliği” ne göre hazırlanmıştır.
MADDE 4 – (1) Bu Tebliğde geçen:
a) Malt: Bira üretiminde kullanılan başta arpa olmak üzere diğer tahılın kontrollü koşullarda su ile çimlendirildikten sonra kurutulup kavrulmuş halini,
b) Şerbetçiotu: Biraya karakteristik aroma ve acılık verici özellikleri kazandırma ve koruma amaçlı katılan Humuluslupulus adlı kültür bitkisini veya bu bitkinin fiziksel veya kimyasal veya hem fiziksel hem de kimyasal işlem görmüş halini,
c) Ekstrakt maddeleri: Kuru madde konsantrasyonunun sağlanması için ilave edilen malt, tahıl ve tahıldan elde edilen ürünler, bira konsantresi, malt konsantresi, şeker, maltoz ve malto dekstrini,
d) Bira: Sadece maltın veya malt ve ekstrakt maddelerinin öğütülüp, sıcak su ile belirli yöntemlerle işlenmesi sonucunda elde edilen şıranın; şerbetçiotu ile kaynatılması ve soğutulması, bira mayası ile fermente edilmesi ve dinlendirilmesinden sonra, filtre edilerek veya edilmeyerek, pastörize edilerek veya edilmeyerek üretilen içinde çözünmüş halde karbondioksit bulunan bulanık veya berrak içkiyi,
e) Alkolsüz bira: Sadece maltın veya malt ve ekstrakt maddelerinin öğütülüp, sıcak su ile belirli yöntemlerle işlenmesi sonucunda elde edilen şıranın; şerbetçiotu ile kaynatılması ve soğutulması, bira mayası ile belirlenen alkol derecesine kadar fermente edilmesi veya fermentasyon sonucu oluşan alkolün uzaklaştırılması yoluyla elde edilen, filtre edilerek veya edilmeyerek, pastörize edilerek veya edilmeyerek üretilen, içinde çözünmüş halde karbondioksit bulunan bulanık veya berrak içkiyi,
f) Aromalı bira: Aromatize edilmiş bira ve aromatize edilmiş alkolsüz birayı,
g) EBC birimi: Avrupa Biracılık Komitesi tarafından yayınlanan biranın renginin değerlendirilmesinde kullanılan ölçü birimini,
In the production of beer the first step is producing ‘from barley malt a “wort”.
Wort is then combined with flavour producing agents such as hops, additional carbohydrates, etc. and then fermented with yeast to obtain a beer which can be further modified as desired.
Method of producing a low alcohol beer comprising producing a wort, removing from the wort at least some of low molecular weight fermentable components, and then processing the wort to make a beer.
The wort of a beer includes carbohydrates in which the low molecular weight components such as the mono, di and trisaccharides are those which are most susceptible to fermentation by an active yeast in the beer making process.
In fermentation the lower molecular weight saccharides are converted to alcohol while the higher molecular weight carbohydrates and other materials added or inherently present in the wort do not ferment to the same extent as the lower molecular weight components and provide the calorific value and also the flavour of the beer.
The alcohol content in the final beer can be further varied by the degree of fermentation and by dilution with water.
The wort is subjected to a separating technique that are known as ultrafiltration process, Reverse Osmosis (R.O.) membranes and processes.
Inventor: Ian E. Ogden, 53 Makara Road,Karori, Wellington, New Zealand
Date of Patent:Jul. 24, 1990