Suitable Emulsifiers for Hop Oil Emulsions

Hop oil emulsions prepared from different varieties of hops have been found to exhibit enhanced physical stability on the addition of blends of the emulsifiers Span 20/Tween 80 or Span 60/Tween 60. Examination of the particle size and volume distributions of an emulsion by use of a Coulter Counter was found to be an excellent method of monitoring its stability. An indication as to the relative efficiency of emulsifiers can be obtained from Coulter Counter measurements on hop oil emulsions after storage for 4 days. The use of an ultracentrifuge provies a rapid means of testing emulsion stability and hence the effectiveness of emulsion stabilizers.

Stability of Aqueous Emulsions of the Essential Oil of Hops

Chilton¹,

Laws²

1980

The Essential Oil of Hops a Review

Sharpe¹,

Laws²

1981

Use of Extracts Prepared With Liquid Carbon Dioxide as a Substitute for Dry Hops

Scort¹,

Theaker²,

Marsh³

et al. 1981

Liquid carbon dioxide hop extracts were prepared for use as a substitute for dry hops. Many of these extracts were oil rich fractions containing up to 14% (w/w) hop oil. Extracts of Styrian Golding, Wye Target and Wye Northdown hops were used to treat ales prior to completion of beer processing and subsequent packaging. Emulsion/suspension systems were developed as carriers to facilitate addition of these extracts to beers before the chilling process. A loss of hop character from beer was found to occur during fining and filtration. Beers, treated with the extracts, exhibited natural though varietally distinct dry hop character. Production scale trials using these extracts have been successfully carried out to dry hop a brewery conditioned draught bitter and to match a traditionally dry hopped premium pale ale. The quantities of extract used indicated that economies in hop usage can be achieved when substituting liquid carbon dioxide hop extracts for dry hops.