Tetrahop Gold® is an aqueous alkaline solution of the potassium salts of tetrahydro-iso-?-acids. It is produced from CO2 hops extract using a patented all aqueous process. Tetrahop Gold enhances beer foam when used as a post-fermentation replacement for a part of the normal bittering. In the absence of normal ?-acids and iso-?-acids, Tetrahop Gold will give complete protection from the formation of lightstruck flavour. Furthermore, it will act as an antimicrobial agent when added to beer.
Description: A yellow to amber colored, aqueous solution of the potassium salts of tetrahydroiso-?-acids.
Concentration: Standard concentration is 9.0% ± 0.5 of tetrahydro-iso-?-acids by HPLC
pH: 8.5 – 11.0
Density: 1.017 g/mL (approximately) at 20 °C (68 °F)
Viscosity: 2 – 10 mPas at 20°C
Solubility: Soluble in pH-adjusted de-mineralised water, and in alcohol
Iso-?-acids: < 0.1%
The following calculations are based on the assumption of tetrahydro-iso-?-acids (THIAA) being 1.7 times as bitter as iso-?-acids (IAA). Utilisation of THIAA is expected to be up to 70 – 75% when Tetrahop Gold? is used as recommended.
Desired Sensory Bitterness Units = BU
THIAA required in beer (mg/L) = BU / 1.7
Dosage THIAA in mg/L (70% utilisation assumed ) = (BU / 1.7) x (100 / 70)
Dosage in grams THIAA per hL of beer = (BU / 1.7) x (100 / 70) x (100 / 1000)
Dosage amount of Tetrahop Gold (9% THIAA)in g/hL :
(BU / 1.7) x (100 / 70) x (100 / 1000) x (100 / 9) g/hL = BU x 0.93g/hL
Dosage amount of Tetrahop Gold? (9% THIAA) in mL/hL :
(BU / 1.7) x (100 / 70) x (100 / 1000) x (100 / 9) x (1 / 1.015) = BU x 0.92 mL/hL
(e. g. for 5 desired sensory bitterness units 5/1.7 X 100/70 X 100/1000 X 100/9 =
4.7 g/hL (4.6 mL/hL) of Tetrahop Gold are necessary)
Calculate required Tetrahop Gold as shown above (for foam and cling enhancement we generally recommend Tetrahop Gold not be added to the final beer at a concentration greater than 5 ppm THIAA). Reduce kettle bittering by an equivalent BU to compensate for the bitterness contribution of Tetrahop Gold.
Tetrahop Gold? will only provide protection from light-struck flavour if a complete absence of normal iso-?-acids is achieved, therefore no other sources of non-reduced iso-a-acids should exist in the wort or beer streams. Thus for light-stable beers packaged in clear or green glass bottles, all the hop bitterness must be derived from reduced hop acids such as Tetrahop Gold, Redihop or Hexahop products. Iso-?-acids (from equipment or yeast) must not be present in the beer. If beta extracts are used as kettle additives, ensure that the concentration of a-acids and iso-?-acids are below 0.2%
Store Tetrahop Gold in full, closed containers at 15 – 25 °C (59 – 77 °F). Prolonged storage at high temperature will cause deterioration.
BEST BEFORE DATE
Tetrahop Gold performs best if used within 24 months from the time of production if stored as recommended. Opened containers should be used within a few days.