Rum Aging Science American Oak Barrels
Rum Aging Science Oak barrels
Introduction
In our first 12-part series, published from January through December 2020, we explored the transformation of rum, while aging in an ex-whiskey barrel. We selected an ex-whiskey barrel for that initial series because the majority of the rum aged around the world employs this type of barrel. The reason for the popularity of this choice is the fact that whiskey producers are required to age their spirit in new oak barrels and, once emptied, they cannot re-fill the barrels, thus creating a surplus of barrels that many other spirits are happy to use in their aging programs.
During the course of the first series, we received a considerable number of inquiries, asking how the results presented would differ if we were using new barrels. This new 12-part series is devoted specifically to address this topic: we will be conducting the same type of research as we did previously, examining the month-to-month changes to the rum while it ages in a new barrel, but also presenting side-by-side comparisons to the corresponding results from the used barrels.There are many different levels of heat treatment that can be applied to a new barrel. This series focuses exclusively on American Oak with a Char #1 (staves and heads), from Independent Stave Company/Missouri Cooperage. Future series will explore different Char and toast level combinations, as well as, barrels constructed using French Oak.
August’s Weather
August was, on average, a very hot month. We experienced a spell of cooler weather mid-month, but the temperatures quickly soared back to “normal” levels afterward. The daily “low” temperatures have been inching their way up, with some days experiencing a low temperature of 82F (28C).
August Temperature
The lack of rain has resulted in a decrease in the relative humidity inside the warehouse, with the average approaching 62% toward the end of the month.
August Humidity
Hot Tea Anyone?
Just like it is easier to brew a nice, rich cup of tea using hot water, rather than cold water, so is the process of extracting flavors and aromas from the barrels: the hotter the warehouse is, the hotter the rum will be inside the barrels, resulting in higher extraction rates. As such, we expect August to be at peak extraction month, flavor-wise.
These are the pH readings, as recorded on the 1st day of each month, compared to the rum from the previous series, which was aged in an ex-Bourbon barrel:
pH readings for August
And these are the changes in ABV % readings (as of first day of each month), also compared to the ex-Bourbon barrel:
ABV% reading for August
Color Transformation of Rum in August
Color: While it is true that many commercially-available rums achieve this color through the addition of caramel, the colors you see on the previous page have been achieved genuinely and naturally, through patient aging in oak.
Taste: The flavor has come a long way, from the white, un-aged rum that filled the barrel at the beginning of the year, to a rich combination of tannins, wet oak, light traces of smoke and a finish that gets better after each passing month. Right now it is promising to be a very decent, young sipping rum after only 1-2 years, we’ll see.
Join us again next month, as we continue to explore the fascinating world of rum aging!