These resins can then be standardized to a particular alpha percentage with glucose. Hop resin extract will vary depending on the hop variety extracted, and usually contains from 40 to 60% alpha acids.

Supercritical carbon dioxide extraction is the newest hop extraction technology available. This extract is typically a golden yellow color when produced. It is free flowing at elevated temperatures and is a semi-solid paste at room temperature. CO2 extract has excellent storage properties, and can be packed in different container sizes from 1/2 kg. cans up to 200 kg. drums, depending on the brewer's needs. The resin's active ingredients remain intact over extended periods of time assuring the brewer consistent brewing characteristics.

The resin has a pronounced hop aroma, and is a pure product; that is, no foreign substance is used in processing it, just pure CO2, a natural product of the fermentation process in beer.

The low temperatures and high pressure used during processing plus the inert nature of supercritical carbon dioxide combine to produce exceptional efficiency in extracting the alpha acids. Supercritical CO2 extraction is a hi-tech, state of the art process providing the brewer with the highest quality product possible.

There are various types of solvent extracts. Hexane is an older technology using a strong, highly flammable solvent. In Germany ethanol is used as a solvent to extract the hop resins. Solvent extracts are generally being phased out in favor of Super-critical CO2 extracts.

Hop extracts are used primarily for bittering the beer. They typically add little aroma, and often a brewer using extracts will add aroma pellets later in the brewing cycle.

Newest hop extract product are the Tetra extracts, particularly favored by those who put their beer in flint (clear glass) bottles.

Tetra Iso-Extract provides protection from light-struck flavor, but only in the absence of normal, iso-cc-acids bittering. In this regard, it is important that no other sources of non-reduced iso-a-acids are inadvertently introduced into the wort or beer. (Common sources of contamination are equipment surfaces and pitching yeasts that have had previous contact with iso-alpha acids).

Hopsteiner Tetra ISO-Extract can be safely used in conjunction with Hopsteiner Reduced ISO-Extract to achieve beer light stability together with ideal foam and bitterness characteristics. Hopsteiner Tetra ISO-Extract provides 1.6 to 1.8 times the perceived bitterness as compared to the same IBU level from traditional hopping. Tetra ISO-Extract also provides improved foam retention and cling.