HVG Germany: Hopfen


Beta-acid products  
Beta- acids are gained in the fractionation of the resins. These products are dosed into the copper as emulsions (partly together with the oil fraction) in the brewhouse. This process can be used In making "light stable" beers In order to avoid the copper frothing over, to produce a certain microbiological protection and to counteract a too malty wort-flavour in the beer. Some unspecified oxidation products of the beta-acids enter the solution in low concentrations. 

Isomerised products 
The use of pre-isomerised extracts and pellets is not intended to obtain a special character in the beer but is generally made for reasons of cost. Isomerized products should contribute a basic bitterness in the form of iso-alpha-acids. The hop oils and polyphenols of these products are considerably changed or reduced compared with the fresh hops. At the same time the original characteristics of a hop variety are lost.
The aim is to save money In the use of raw commodities.
As pre-isomerized downstream extracts iso-alpha acids can be added prior to filtration to correct the bitter units. In this way a product with stronger bitterness can be produced e.g. also from a mildly hopped beer in the filtration.

Reduced products  
Also used as downstream products these hop products are usually added prior to filtration.
Consequently two main problems are dealt with:
Froth problems and light struck flavour with the beer in light glass bottles.
Increased contents of reduced iso-alpha-acids can cause an untypical froth and an unusual, changed bitter taste. Therefore special attention must be paid when dosing them.

Xanthohumol preparations
They are a new product in the beverage industry. New preparations are being developd for dosage In the brewhouse as well as for the post-fermentation (following the fermentation). In the beer xanthohumol in higher concentrations produces a lasting turbidity which is similar to the yeast turbidity in white beer