We have developed a special solution called Tetrahop Gold® that improves beer froth in the long term.
In so-called Late Hopping, cone hops are extracted particularly gently. This process takes place between the whirlpool and wort cooling. It enables an ideal transfer of the hop oils into the wort.
In Dry Hopping (German "Hopfenstopfen") the hops are added to the beer only after its main fermentation. In this way, a very special hop aroma is created. By the way, "Dry Hopping" is so called because primarily dried hops are used.
Dry hopping probably originated in the UK where is was first applied to cask ales.
Hop extracts for dry hopping usually don't contain iso alpha acids. PHAs contain only hop oil. Hop emulsion contain unisomerised alpha acids, which contribute very little to overall bitterness.