title: Rapid maturation of whiskey

authors: Button, Kaitlin

subjects: Whiskey

abstract: Whiskey is among the oldest and one of the most consumed spirit based drinks in the world. Traditionally whiskey is aged for three or more years in wooden barrels to mature the spirit. During maturation, a variety of compounds are extracted from the wood to give a complex mixture of flavours and aromas. It is desirable to speed up the reactions which take place during maturation including, extraction of compounds from wood and reactions between the distillate and wood compounds. The benefits of ageing the spirit faster are the reduction in storage space, time and costs associated with the ageing process. 
This project was carried out for a commercial company with a focus on maturing fresh distillate using different ageing techniques; heat, light, heat-freeze and sonication with wood chips to obtain the flavours and aromas associated with mature whiskies in a short timeframe. Quantitative (concentration, ppm) and qualitative (peak areas, ISTD corrected) analysis was carried out on samples stored over time using gas chromatography mass spectrometry (GC MS). 
Initially, different sized wood pieces (toasted to varying degrees) were soaked in 65% ethanol, to replicate a whiskey matrix, and heated over four weeks to confirm what compounds were extracted from the wood and their relative quantities. The ethanol experiment also allowed determination of the optimal temperature (70 °C), time (≤ 14 days), wood size (small chips) and toasting level (medium toast) to extract compounds in a short timeframe with similar levels to the analysed commercial samples. 
Heat, light, heat freeze and sonication treatments were separately applied to fresh distillate (corn and malt) with different wood sizes and toasting levels. Experiments were sub sampled over time. The determination of the compounds present and the effects of different treatments on the concentrations/peak areas were compared. Experiments were also compared to commercial samples (n = 51) to investigate whether a mature whiskey profile had been achieved. 
Samples heated (70 °C) for six days had some desirable compounds (furfural, 1,1 diethoxyethane, several esters and several phenolic aldehydes) at concentration/peak areas similar to commercial samples. Sonication (≤ 8 hours) with medium toast small chips also produced good results for several reasons; the colour and aroma were similar to commercial samples and it had a similar compound profile to commercial samples for the analysed compounds. Furthermore, untargeted analysis using principal component analysis indicated that the corn distillate sonication samples (non-heated and 50 °C) and heat freeze (day 9) samples were clustered with the 10-12 year-old whiskey sample group whereas the heat-only samples were clustered further away. In comparison, the malt distillate samples did not cluster near any of the commercial samples. Linear discriminant analysis was used to categorise the heat, heat-freeze and sonication samples to an age group based on the model created from the analysed commercial samples with 90%  predicted to have a chemical profile ≥ 10 years old (≥ 72% probability). Overall, several age treatments show promise in rapidly maturing whiskey.

text: Rapid maturation of whiskey Whiskey is among the oldest and one of the most consumed spirit based drinks in the world. Traditionally whiskey is aged for three or more years in wooden barrels to mature the spirit. During maturation, a variety of compounds are extracted from the wood to give a complex mixture of flavours and aromas. It is desirable to speed up the reactions which take place during maturation including, extraction of compounds from wood and reactions between the distillate and wood compounds. The benefits of ageing the spirit faster are the reduction in storage space, time and costs associated with the ageing process. 
This project was carried out for a commercial company with a focus on maturing fresh distillate using different ageing techniques; heat, light, heat-freeze and sonication with wood chips to obtain the flavours and aromas associated with mature whiskies in a short timeframe. Quantitative (concentration, ppm) and qualitative (peak areas, ISTD corrected) analysis was carried out on samples stored over time using gas chromatography mass spectrometry (GC MS). 
Initially, different sized wood pieces (toasted to varying degrees) were soaked in 65% ethanol, to replicate a whiskey matrix, and heated over four weeks to confirm what compounds were extracted from the wood and their relative quantities. The ethanol experiment also allowed determination of the optimal temperature (70 °C), time (≤ 14 days), wood size (small chips) and toasting level (medium toast) to extract compounds in a short timeframe with similar levels to the analysed commercial samples. 
Heat, light, heat freeze and sonication treatments were separately applied to fresh distillate (corn and malt) with different wood sizes and toasting levels. Experiments were sub sampled over time. The determination of the compounds present and the effects of different treatments on the concentrations/peak areas were compared. Experiments were also compared to commercial samples (n = 51) to investigate whether a mature whiskey profile had been achieved. 
Samples heated (70 °C) for six days had some desirable compounds (furfural, 1,1 diethoxyethane, several esters and several phenolic aldehydes) at concentration/peak areas similar to commercial samples. Sonication (≤ 8 hours) with medium toast small chips also produced good results for several reasons; the colour and aroma were similar to commercial samples and it had a similar compound profile to commercial samples for the analysed compounds. Furthermore, untargeted analysis using principal component analysis indicated that the corn distillate sonication samples (non-heated and 50 °C) and heat freeze (day 9) samples were clustered with the 10-12 year-old whiskey sample group whereas the heat-only samples were clustered further away. In comparison, the malt distillate samples did not cluster near any of the commercial samples. Linear discriminant analysis was used to categorise the heat, heat-freeze and sonication samples to an age group based on the model created from the analysed commercial samples with 90%  predicted to have a chemical profile ≥ 10 years old (≥ 72% probability). Overall, several age treatments show promise in rapidly maturing whiskey.

year: 2020

title: The hydrodynamics of the southern basin of Tauranga Harbour

authors: Tay, H.W.

subjects: hydrodynamic model

abstract: The circulation of the southern basin of Tauranga Harbour was simulated using a 3-D hydrodynamic model ELCOM. A 9-day field campaign in 1999 provided data on current velocity, temperature and salinity profiles at three stations within the main basin. The tidal wave changed most in amplitude and speed in the constricted entrances to channels, for example the M2 tide attenuated by 10% over 500 m at the main entrance, and only an additional 17% over the 15 km to the top of the southern basin. The modelled temperature was sensitive to wind mixing, particularly in tidal flat regions. Residence times ranged from 3 to 8 days, with higher residence times occurring in sub-estuaries with constricted mouths. The typical annual storm events were predicted to reduce the residence times by 24%–39% depending on season. Model scenarios of storm discharge events in the Wairoa River varying from 41.69 m3/s to 175.9 m3/s show that these events can cause salinity gradients across the harbour of up to 4 PSU.

text: The hydrodynamics of the southern basin of Tauranga Harbour The circulation of the southern basin of Tauranga Harbour was simulated using a 3-D hydrodynamic model ELCOM. A 9-day field campaign in 1999 provided data on current velocity, temperature and salinity profiles at three stations within the main basin. The tidal wave changed most in amplitude and speed in the constricted entrances to channels, for example the M2 tide attenuated by 10% over 500 m at the main entrance, and only an additional 17% over the 15 km to the top of the southern basin. The modelled temperature was sensitive to wind mixing, particularly in tidal flat regions. Residence times ranged from 3 to 8 days, with higher residence times occurring in sub-estuaries with constricted mouths. The typical annual storm events were predicted to reduce the residence times by 24%–39% depending on season. Model scenarios of storm discharge events in the Wairoa River varying from 41.69 m3/s to 175.9 m3/s show that these events can cause salinity gradients across the harbour of up to 4 PSU.

year: 2013

title: Ki te kapu o taku ringa - In the palm of my hand

authors: Hill, Rodrigo

subjects: Mātauranga Māori

abstract: This publication accompanies the launching of our exhibition 'Ki te Kapu o Taku Ringa - In the Palm of My Hand' at the Ōtorohanga Museum in June 2024.
The title is taken from a line of King Tāwhiao's song-poem 'Maioha mō Waikato'. Ejected from their homelands he and his Waikato brethren took refuge with their Maniapoto relations in Te Nehenehenui; parts of which are mentioned in the song-poem. Teh 'maioha' was composed expressing King Tāwhiao's love for his homelands, and his solastagic holding fast to those lands '...in the palm of his hand.'

text: Ki te kapu o taku ringa - In the palm of my hand This publication accompanies the launching of our exhibition 'Ki te Kapu o Taku Ringa - In the Palm of My Hand' at the Ōtorohanga Museum in June 2024.
The title is taken from a line of King Tāwhiao's song-poem 'Maioha mō Waikato'. Ejected from their homelands he and his Waikato brethren took refuge with their Maniapoto relations in Te Nehenehenui; parts of which are mentioned in the song-poem. Teh 'maioha' was composed expressing King Tāwhiao's love for his homelands, and his solastagic holding fast to those lands '...in the palm of his hand.'

year: 2024