Variety Specific Hop Oil
Varietal hop oils are whole, unblended oils prepared by vacuum distillation of liquid CO2 hop extract under carefully controlled conditions. Ultimately, this gentle extraction process presents the essential oils in an undamaged condition and in very high yield. Hop oils contain the full range of essential oils present in each specific variety and do not contain any soft resins or other hop components. They retain the full aroma character of the specific hop variety and are suitable for use on a pre- or post-fermentation basis to provide consistent late hop or dry hop character.
Description: Yellow to amber liquid
Hop oils: 100% of specified variety (or specified blend)
Density: 0.8 – 0.9 g/ml
Iso-α-acids: < 0.1 %
α-acids: < 0.1 %
β-acids: < 0.1 %
For best results, varietal hop oils should be added post-fermentation and prior to filtration. They can be added during kettle boil or pre-fermentation, however, there is a note of caution using the products in this way. Kettle boil additions result in very low hop oil aromas due to the dispersion and expulsion of the volatile compounds. Yeast metabolism alters hop oil compounds if the oil is added pre-fermentation, resulting in different hop aromas. Hop oils are not readily soluble in beer “as is” and, therefore, should be dispersed in a suitable carrier for dosing.
To prepare the oil in a carrier, mix the required volume of oil with five volumes of hop oil base by vigorous shaking or mixing. The shaking or mixing will result in an unstable dispersion that needs to be added to a small volume of beer immediately and thoroughly mixed again before moving forward. At this point, the beer/oil suspension is then blended in with the untreated bulk of the beer.
Addition rates depend on the point of dosage. A kettle addition will require 1.5-6 g/bbl, while the recommended pre-fermentation rate is 0.5-2.5 g/bbl. For an addition prior to filtration, the suggested range is 0.25-1.0 g/bbl depending on the desired aroma and taste, and the characteristics of the base beer. Dosing experiments, using a pipette or microlitre syringe, will give useful indications of the required quantity.
Methods of Evaluation:
Pilot trials and evaluations are recommended to gain experience with hop oil in brewing plants of any size. The following procedures are suitable for an initial evaluation of hop oil on a small scale or laboratory basis. To follow these procedures you will need a 1 ml syringe graduated in 0.1 ml increments in addition to hop oil and hop oil base.
Barrel basis: (31 gallon U.S. Barrel) Take 0.25-1.0 grams hop oil (depending on beer style and sensory analysis). Use a ratio of one part hop oil to five parts hop oil base to make solution. Shake vigorously until dispersion is obtained. Add the freshly prepared suspension to 50 ml beer and mix well. Add 30 ml of the beer suspension to a barrel of beer and leave to stabilize. Compare the taste of the treated beer with untreated. Repeat the addition of freshly prepared suspension until the desired taste is achieved.
Bottle basis: (12 oz. U.S. Bottle) Take 0.1 ml hop oil and add to 0.5 ml of hop oil base. Shake vigorously until dispersion is obtained. Add the freshly prepared suspension to 140 ml of beer and mix well. Chill a 355 ml bottle of beer to normal drinking temperature. Remove the crown cap and add 0.5 ml of the beer/oil suspension to the bottle beneath the surface of the beer. Tap the side of the bottle to induce fobbing and expulsion of the air. Reclose the bottle with a manual crown cap, invert several times to ensure mixing and re-chill for at least two hours before opening and tasting. Each 0.5 ml of the prepared beer/oil suspension added to a 12 oz bottle results in the addition of 1 ppm hop oil to the beer. Prepare several bottles at concentrations up to 5 ppm of hop oil for testing and select the desired level of taste.
Normally packed in glass bottles containing 25 g of oil.
Also available in 1 kg and 5 kg aluminum flasks.
Storage and Shelf Life:
Hop oils should be stored in full, closed containers at 37-43°F, and are best if used within 24 months of purchase. After 24 months of storage, it is recommended that an analysis be conducted to determine activity for necessary dosage adjustments.
For the analysis of the composition of hop oils, gas chromatography (GC) techniques are used. Details of this method are available upon request.
We will be pleased to offer support on the use of hop oil in brewing. For assistance, please contact our knowledgeable staff at 1-800-952-4873 or e-mail firstname.lastname@example.org.