Technology

a look back

AromaLoc™ was invented in October, 2012, when Dr. Dick Jones, a retired pulmonary research scientist, began making wine from grapes he grew in the Okanagan area of British Columbia.  He called his small vineyard “Sweetspot” because of the beautiful setting of steep hillsides and the stunning waterfall visible only from his house.

He planted his vineyard on the steep hillside facing the waterfall.  His background in lung gas exchange equipped him to react to a problem he noticed during his first year of making wine from his own grapes.  He noticed nice aromas coming out of a tank of Pinot Gris during fermentation, and he immediately thought of ways to prevent what he later learned was called CO2-induced aroma stripping, and keep the aromas in the finished wine.  After a literature search, he was surprised that no one had tried to solve this 8,000 year-old problem using the method he had in mind.

A special membrane would be required.

Since winemaking happens only once per year, he needed to do something immediately to see if his method to preserve aroma made any difference to a batch of Pinot Gris that was already near peak fermentation.  Searching through the things kept when he retired, he found a container of soda lime, a granular material that absorbs CO2.  He quickly set up a tiny study, and used only about 1 litre of the fermenting Pinot Gris.  He let the headspace gas flow through the soda lime to remove some of the CO2 and returned what was left to the headspace above the 1 litre sample.  After fermentation was complete, he got only one bottle of the experimental wine, which was compared to the larger volume that was left untreated.   A local wine expert blindly sampled the two wines and confirmed Jones’s impression that the experimental wine had significantly higher aromatics.

After an exhaustive hunt, Jones managed to find an appropriate membrane he felt would work. Over the following winter, Jones continued researching aroma preservation techniques and conducting experimental trials.  His idea was novel, so he embarked on the demanding patent application process.

 He worked with Paul Gardner, a commercial winery owner, to build a membrane housing and prepare for the 2013 winemaking season. Using his invention on white and rosé wines would be straightforward, but red wine fermentations posed challenges due to the need for cap management while still keeping the headspace gas tight.  Solutions were developed and more was learned. As with any testing, as questions were answered others were created.  Unfortunately, the 2013 winemaking season was a bust as the membranes froze during shipping making them useless.

Undaunted, in 2014 Jones flew to Europe and personally brought back four membrane sheets. These membranes were used during many trial experiments to test the theory that concentrating aroma in the headspace could reliably translate into retention of aroma in the finished wine. Without exception, the experiments were successful — it was now time to test larger wine volumes.

In 2015, two hollow fibre membrane modules were obtained.  This configuration allowed for a large membrane surface area in a small footprint — thus they could handle larger CO2 volumes from larger fermentation volumes.  In that year the first experiment on a small, commercial-size fermentation was conducted, using side by side 700 litre volumes of Pinot Gris.

The protocol for all past and current trials is to have a large tank of wine or must which is ready for fermentation. Any adjustments are made to this entire volume, and it is inoculated with the desired yeast.  It is then mixed and racked into two identical tanks which are fermented with the same parameters. One of the tanks is fitted with the prototype invention (experimental), and the other is allowed to vent CO2 in the conventional manner (control). 

Results from a Pinot Gris 2015 trial can be seen below.  This tasting, like all others, was carried out by a tasting panel comprised of accredited industry professionals.

The control and experimental  results are presented in two different ways to make visualization easier. The spider graph (Figure 1) compares the experimental wine (red line) to the control wine (blue line), and is expressed as the percent change from control.  On the bar graph (Figure 2), the control is represented by zero on the graph.  When AromaLoc treated wine scored higher than control, the bar is greater than zero. It is clear that for all seven attributes tested, the AromaLoc treated wine scored higher, especially for aroma and overall rating.

 
Figure 1 — Spider graph 
 
 
Figure 2 — Bar graph

These same wines were sent to the Wine Research Centre at the University of British Columbia for Gas Chromatography/Mass Spectrometry analysis of the levels of individual aroma compounds.  Figure 3 shows that most of the volatile aroma compounds were higher in the membrane-treated wine (bars above zero), which was consistent with the blind tasting findings.

Figure 3

The results of the 2015 experiment led to the design of a machine around the process used at the time, and the company “AromaLoc™” was legally formed in 2016.  A workshop was obtained, and 10 machines were constructed that could handle up to several thousand litres of fermenting wine. These machines were constructed to be commercially viable. This configuration worked very well, but blind tastings on 2016 wines revealed that despite noticeable increases in the retained aromas ,there was a slight bitter aftertaste picked up by some tasters.  To get answers, various analyses of individual aroma compounds from previous experiments were reviewed, and it was discovered that although many of the fruity esters were augmented in the AromaLoc treated wine, so were the fusel alcohols.

Having succeeded in achieving aroma preservation, the issue of fusel alcohol retention presented a new challenge that needed to be resolved, without affecting retention of the beneficial aromas.  It took a redesign of the machine to achieve this.  Small-scale prototype machines were tested on wine kits and beer during the summer of 2017, and on local grapes in the fall of 2017. The results confirmed that the modifications were successful in enhancing desirable aromas and eliminating bitter aftertaste.

Larger AromaLoc machines were tested in the fall of 2017 with positive results, and additional knowledge was acquired regarding how best to use the technology. In 2018, a collaboration opportunity with an ultra-premium winery in the Napa Valley presented itself, and it was decided to go outside the partners’ wine region for independent evaluation of the AromaLoc technology.

There were two challenges in this trial.  First, a red wine was going to be fermented, which necessitated the design of a punch down tool that could maintain the gas-tight headspace. Second the fermentations were being done in wooden barrels, so a gas-tight seal was also needed.  TN Coopers worked with AromaLoc, and developed a solution to both of these issues.  AromaLoc built a machine capable of treating 4 barrels simultaneously. The 2018 Cabernet Sauvignon trial convinced the winery to continue with another trial in 2019.  For that trial, TN Coopers refined the barrel head and punch down system, and now have it available as a commercial unit for use with AromaLoc.

Local 2018 trials in the Okanagan Valley were also a success, on fermentation volumes ranging from 18 litres to 2200 litres (see below).

2018 okanagan valley trials

AromaLoc trials to this point have been done at several boutique wineries in British Columbia’s Okanagan wine region, and the ultra-premium USA winery mentioned above. Through blind tastings with industry qualified professionals and hobbyists, and on GC/MS analyses, the AromaLoc system has been fine-tuned to be scalable from 20L to virtually any size.

During seven years of research and development, we have conducted dozens of fermentation trials. In all AromaLoc trials, the juice is inoculated with yeast and well mixed before filling the control and AromaLoc trial fermenters.The results are blind tasted by industry professionals using both the control and AromaLoc treated products.  Examples of 2018 tasting results on wine are shown below.

The blue lines are control and red lines AromaLoc treated. We are regularly getting at least 20% increases in rating categories, and as can be seen, the increased aroma also affects different characteristics of the beverage. 

 Pinot 
 
Noir Rosé 2018, tasted by 16 wine professionals  

 

Pinot Gris 2018 tasted by 16 wine professionals

 

Viognier 2018 tasted by 16 wine professionals

2019 Pinot Blanc Trial

 

This graph shows the change in each measured aroma compound in AromaLoc treated Pinot Blanc compared to identical compounds in the control wine.  This is plotted against the hydrophobicity of each compound (logP).  Low values for logP are typical for fusel alcohols (red points).  The more hydrophobic fruity esters (blue points) are represented by higher logP values.  Generally, the red points did not change or decreased while many of the blue points representing the esters increased with AromaLoc treatment.  The results are interesting, because there is a linear relationship between logP and the percentage change with AromaLoc treatment.  This is exactly what AromaLoc was meant to achieve.  The increases with AromaLoc are greater for the hydrophobic esters, and less or non-existent for the fusel alcohols.  This translates into an aroma profile favoring fruity notes without a bitter alcoholic taste.