Top Fermented Beers

Lysophosphatidyl cholines (LPC), which occur in cereal as amylose inclusion compounds (starch lipids cf. 15.2.5), reduce the foam stability. The terrqterature management during the mashing process regulates the LPC concentration because it determines the activity ratio of a-amylase, which contributes to the release of LPC from amylose, to phospholipase B, which catalyzes the 

Selected examples of top fermented beers from Germany are Berlin weiss beer, brewed from a wort having 7-8% solids from barley and wheat malts and inoculated at fermentation with yeast and lactic acid bacteria Bavarian weiss beer brewed from weakly-smoked barley malt with a little wheat malt and fermented only with yeast Graetzer beer made from wheat malt with a smoky flavor and with a stemwort content of 

Pale ale is strongly hopped light beer, whereas mild ale is mildly hopped dark beer. Incorporation of ginger root essence into these beers yields ginger-flavored ale. 

Top fermented beers from Belgium, which are stored for a longer time, are called Lambic and Faro beers. 

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Since the 1960s the overall number of types has been decreasing, or at least remained unchanged (standard products), but some figures indicate that in the future the creation of new products might take place as a strong alternative to the previous mass-produced beers of less body or character. A traditional and overall grouping of beer can nevertheless stiU be made, ie, bottom-fermented beet and top-fermented beer. 

Lambic Beer. Lambic beer is made in Bmssels and is one of the few top-fermented beers stiU brewed in Belgium. It is made from 60% barley... 

Others. The only top-fermented beer ia Scandinavia is Hvidt Lp. it has a low alcohol content (2.6% vol), a high level of extract, and is very mildly hopped. Smoke Beer is manufactured ia Germany and Denmark. It is made entirely from malt that is dried by direct beechwood fumes. In Denmark it is called Skibs Lp. (Ships Beer) and for centuries was iatended for consumption ia the Danish Navy and Marines siace it had better keeping quahties than the ordinary beers. It is top-fermented with low alcohoHc content. 

Infusion Method. Infusion is a classic method for top-fermented beers and is used for ad British types. The whole mash is heated graduady from mashing-in to mashing-off with holding times for the degradation of protein and starch. No part of the mash is boiled and the malt, therefore, must be well-modified to assure the breakdown of ad soluble substances. Because no boiling takes place there is no physical breakdown of the malt, and consequentiy infusion is not as effective as decoction despite the better protection of the enzymes. 

The ASBC describe such a method. Some representative values for British beers are given in Table 22.21 where the results are also expressed in kilojoules (1 kcal = 4 184 kJ). Many brewers of low carbohydrate lite beers declare the calorific value (e.g. 26-29 kcal/100 ml) on the label. Beer is also a source of B vitamins containing (values in ppb for lagers and top fermentation beers) biotin (7-18 11-12), nicotinic acid (4494-8607 7500-7753), pantothenic acid (1093-1535 1375-1808), pyridoxine (329-709 341-546), riboflavin (219-420 331-575), and thiamine (15-58 59-181) [117]. Folic acid and vitamin Bj are also present [10]. 

The so called lagtime assay uses forced oxidation combined with EPR spin trapping to effectively measure the antioxidant activity of a beer and to even predict a beers shelf life. It has been well established that the time in minutes (i.e., lagtime) before a dramatic EPR signal increase occurs, correlates with the time in days that are required for a sensory panel to detect the characteristic cardboard off-flavour. A parameter known as the T150 (the EPR intensity at time = 150 minutes) is another metric that is used to evaluate the resistance of the beer to oxidation. The T150 value is particularly used in ale-style (top-fermented) beers which do not have a lagtime. 

In beer, flavanoids could be also responsible for astringency [41, 42]. Catechin and epicatechin thresholds lie between 1 and 20 ppm [41,42], with higher values for the beer matrix (20 ppm). Astringency is intensified at low pH, especially near 4.0-4.2 [43], but a higher astringency has been measured by Franfois et al. [44] in beers with a pH close to 5. In this case, it was suspected that the pH of the samples fell in the mouth before polyphenol/protein interactions occurred. Sensory analyses applied to top-fermented beers have shown that storage (20°C or 40°C with air in the head-space) decreases bitterness and post-bitterness but intensifies astringency [45]. On the... 

Vanderhaegen B, Neven H, Coghe S, VCTstrepen KJ, Verachter H, Derdelinckx G (2003) Evolution of chemical and sensory properties during aging of top-fermented beer. J Agric Food Chem 51 6782-6790... 

Wheat malt is mixed with barley malt in a ratio of 40 60 in the production of top fermented beer. 

In infusion mashing, used mostly in England for brewing top fermented beer, the terminal mashing temperature is achieved not by stepwise increases, but by live steam injection or addition of hot water. As in the decoction method, the temperature program used can vary greatly. 

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