What's Going On Inside that Barrel?

It's been an interesting problem, trying to show what's going on inside a barrel with our technology. The Wizard, like The Symphony before it, agitates the contents inside a barrel. How do we know? Well, we've shown what it can do in a carboy, and so it can be inferred (sorta). But that's really never been good enough for us. You can put your hands to the outside of the barrel and feel it, but that still leaves it to the imagination about what's happening on the inside.

The problem? It's dark in there, and it's plugged with a bung, and it's liquid tight. So. Yeah. Good luck seeing inside. We've seen some barrel-heads replaced with transparent plastic, and that's actually really cool, but turns out it's not the most affordable thing to pursue (like, not at all). Jameson uses a few "see-thru" barrels to show different stages of aging (to good effect, I might add).

We know that color change is only one of the characteristics indicative of maturation, and that color change itself is largely driven by extraction processes between the spirit and the wood. We've also shown through experiment that agitation is very effective at driving color-change (extraction). That being said, color has no flavor. And I don't know anybody that has bought a 2nd-bottle of anything because they loved the color alone. 

Extraction is only one of the processes involved in maturation, the other two are reaction(s) and evaporation. One of my favorite finds on Google of the last year is the very excellent "Chemistry of Whisky" poster provided by compoundchem.com

The poster shows the key flavor compounds present in a matured whiskey. A quick review of our older blog posts would show that these compounds are also in higher concentrations as a result of agitation, quite substantially actually.

But the question remains...what's going on inside that barrel? Well, we finally caved. Destroy a barrel for science? YES! Actually, we just drilled another hole by the bung, a peep-hole of sorts, so that we could see inside without altering the Wizard's operation. I suppose we can just stick a cork or #3 stopper in that hole and use it again.

We filled the barrel up about an inch from the top and stuck a barrel-Wizard in, plugged it in (unlike our previous technology, The Wizard is simply plugged in. Genius, right?), and hit record. Here it is.

And why does that matter? Because in addition to wood extraction, spirits maturation also includes reaction(s) and evaporation, both of which can be heavily influenced (and even driven) by the amount of surface area at the spirit and headspace interface in the barrel. And as you can see in the video, an agitated surface has substantially more surface area than a flat, still surface. And manipulating this interface promotes the many good oxidative reactions and evaporative losses that occur during the barrel maturation processes.

Extraction? Check. Reactions? Check. Evaporation? Check.



Wheater Ale - Homebrewing Experiments

We love beer. We love to make it, we love to drink it, and we love to talk about it. 

Whiskey? Ditto.

Beer + Whiskey = 2 x Awesome + Intangibles

So we set out to make a whiskey beer, or more specifically, a "Wheater" Ale. Basically took a modified grain bill of Maker's Mark and brewed it (no, it's not mostly corn). It smells awesome. But we didn't want to stop there, so we added dry-hops into the secondary along with some charred oak that had been sitting in Maker's Mark (along with the bourbon). 

And it gave us our first chance to try out our latest gadget, the Wizard. The Wizard is quite a beastly tool for homebrewers; it's really just a one-to-one swap with your current stopper+airlock, but it sits in your brew and agitates your carboy on demand. No lifting. No swirling. No handling. In fact, no exposing your beer to the elements at all. We're using it in the secondary in this batch, but could we use it in the primary? You betcha! That's next. We might even use it in our mash tun to see if we can increase efficiency a little bit. The Wizard is made of food-safe high density polyethylene (HDPE). We'll post updates soon.

For now, we just wanted to show you what it does in a carboy. A video can only do so much justice though, you gotta feel the carboy or barrel it's in to really appreciate it. Cheers!

Effects of Agitation on Spirits Maturation - ADI 2016

Had an excellent time attending and speaking at ADI's 2016 Spirits Conference & Vendor Expo this year in San Diego. Coming from the aerospace industry, I can positively say that the last 10 conferences I've been to (at a minimum) pale in comparison when it comes to booth gifts. A typical conference for me is good for a few USB memory sticks, or pens, or samples of solder. This year's ADI conference, however, yielded three flasks, two sets of small bottle tasters, a handful of leather coasters, and some charred oak sticks for my homebrew. Will. Be. Back. 

As promised, a PDF of the presentation can be downloaded at the link here: Effects of Agitation on Spirits Maturation - ADI 2016

5G Barrel Experiments - Results and Rumblings

It's been almost 4-months of side-by-side aging of unaged spirit (white rum, 65% ABV) in new, #4-char, 5-gallon oak barrels, one agitated 24/7 by a Symphony, and the other acting as a control.  The goal of this investigation has been to start quantifying differences in chemistry that occur during barrel-aging, with and without agitation, using generally accepted industry testing practices (GC-MS) and known chemical markers. Although the unaged spirit in this study was rum, our primary interest is the impact of agitation on unaged spirit in new-char barrels, more typical of US Whiskey and Bourbon, and the resulting maturation chemical markers that are derived from the barrel and that are believed to play a prominent role in the final sensory profiles of such wood-matured spirits (1, 2, 3, 4).

(Bonus: we've got some good sippers on our hands as well.) 

As a recap, the Symphony is a wirelessly powered agitation tool that works from inside a barrel to help promote the interaction of the spirit with both the oak and the headspace. The device is designed to be dropped through a barrel's bung hole and to sit on the bottom of the barrel where it agitates the contents inside. 

To get a qualitative idea of the changes occurring during our experiment, a simple snapshot into color change is easy to capture and has also been a useful indicator. Pictures of both the Symphony-aged barrel and the control barrel were taken under identical lighting conditions over the course of three months. The results are shown below. These pictures are a continuation of our previous blog entry, and it's worth pointing out that nothing is added to the spirit and that the pictures in the image below are all taken at cask-strength. 

Although coloring is just one of the changes occurring during barrel-maturation, the difference is fairly noticeable between the two barrels after only three months, even in the bottle after proofing-down to 40% ABV. 

To dive further into the chemical make-up of the spirits after 3-months of aging, samples were tested at ETS Laboratories for their oak aroma characteristics. This test is performed using GC-MS and provides the concentrations of the main oak-derived sensory compounds present in each sample. The image below shows the results from the testing of the 3-month samples on a radar plot, where the blue lines represent the control barrel concentrations and the orange lines represent the Symphony-agitated barrel concentrations. 

With the exception of the furanic compounds (which may themselves undergo further reactions during aging [I've read this somewhere, but still looking for the reference]), all of the compounds tested showed higher concentrations as a result of agitation with the Symphony, with the whisky lactones (cis-, trans-) showing the greatest gains against the control barrel, both testing at concentrations over 2X the control. 

A deeper dive into the available literature shows that for bourbon whiskey, at least as of 2008, Poisson and Schieberle had identified six (6) primary odor-active compounds, shown below.

Of the compounds cited above, a look back at the radar plot shows that (30) cis-whiskeylactone (cis-oak lactone) exhibits a 108% increase relative to the control, (36) 4-allyl-2-methoxyphenol (eugenol) shows a 36% increase, and (45) 4-hydroxy-3-methoxy-benzaldehyde (vanillin) shows a 31% increase over the 3-months test. The other three compounds from the Poisson paper were not available for testing with the standard oak aroma panel.

So where does that leave us with respect to "accelerated maturation"? Depends on the maturation marker and the timeframe of interest. Admittedly, we could run more tests to further develop slope plots, and we likely will as we go forward. To be clear though, our goal at Hertzbier has always been to enable a distiller to get more out of their barrel for a given amount of time, "more" being represented by a variety of compounds present at levels greater than would have been possible without agitation with the Symphony, a "given amount of time" being whatever amount is suitable to the distiller and his/her craft and the goals for their product, and "barrel" meaning just that...conventional oak barrels. For example, the follow on work to the Poisson paper above dives into the chemical makeup of two commercial bourbons bottled from two different years, both aged for at least 3 years in new charred oak barrels. 

Of particular interest are the levels of whisky lactones, eugenol and vanillin given the available test data. A quick comparison with the published literature would suggest that the 3-months of aging 65% ABV spirit in the 5G barrel with Symphony agitation can enable equivalent (or greater) levels of various oak-derived maturation marker concentrations as found in 3-year aged spirit in new, charred 53-Gallon barrels.

To be sure, this is only a small part of the story. There are over some 300+ compounds that have been identified in wood matured spirits, and we've been looking at no more than 10-15 of them. The ester compounds detailed above in the commercial whiskies need also be considered.  Unfortunately our testing hasn't been able to quantify all of those compounds (yet), but instead we've been able to take a snapshot of a couple of esters, ethyl acetate and isoamyl acetate, at both 6-weeks and 12-weeks, as shown.

The ester concentrations above show that the barrel agitated with the Symphony isn't driving these reactions to happen at dramatically accelerated rates when compared to the control barrel, although the relative ester concentrations between 6-weeks and 12-weeks do go up in both cases with the Symphony. Additional testing is still needed to see how changes occur over longer time frames. To more fully understand the bigger picture though, a review of the available literature on the subject leads to a book by Nykanen and Suomalainen which claims that a study of ethyl acetate concentrations in bourbon "had an average concentration of 249 mg/L (249 ppm) in whiskey aged for two (2) years, 369 mg/L (369 ppm) in whiskey aged four (4) years [...]". 

So what does it all mean? Well, taking everything presented above and extrapolating out a few months, we should have a spirit that exhibits a large majority of the maturation markers of a 2-4 year aged bourbon after 4 months of aging in a new char, 5G barrel...it'll just be made of rum. It's already a tasty sipper though, we'll see if we can wait another month.

Ready to enhance one of your barrel-aged products? We're rolling out a small number of units for initial testing and feedback. Get your's here

Rum in 5G barrels - side by side experiments

Finally, at long last, we've got an opportunity to start testing at scales of relevance to the industry. Although still on the small side, 5G barrels are common, and we've seen at least a couple of them in most of the distilleries we've had a chance to visit. Thanks again to our friends at Liberty Call Distilling for the white rum and for locating the barrels (#4 char - Barrel Mill).

To get started, we simply put the barrels on blocks, filled both with about 4.5G each of rum (had some spilloff on the ride home, my car was odoriferous), and slid the transmitter underneath one of them. 

With a fermentation chamber next to a couple of barrels, the garage is starting to look bragworthy. Aforementioned Single Malt Scotch Porter in the background.

With a fermentation chamber next to a couple of barrels, the garage is starting to look bragworthy. Aforementioned Single Malt Scotch Porter in the background.

Testing is going to be performed via GC-MS, and we're still debating what we want to quantify in this batch. Any point on the barrel with the Symphony can be felt to be vibrating, and the control barrel next to it makes for a pretty good comparison of environment and temperature range. GC-MS samples are all 200mL each. A comparison through 6-weeks of aging, showing only color change at this point, are below. 

1 week in 5G barrels (#4 Char) - Hertzbier on the left.

1 week in 5G barrels (#4 Char) - Hertzbier on the left.

2 weeks in 5G barrels (#4 char) - Hertzbier on the left.

2 weeks in 5G barrels (#4 char) - Hertzbier on the left.

3 weeks in 5G barrels (#4 char) - Hertzbier on the left.

3 weeks in 5G barrels (#4 char) - Hertzbier on the left.

6 weeks in 5G barrels (#4 char) - Hertzbier on the left.

6 weeks in 5G barrels (#4 char) - Hertzbier on the left.

At cask strength (about 125 proof), this one will wake up all of your senses.  In fact, with the #4 char it's trending somewhere between a dark rum and a whiskey. With a couple of small ice cubes and a little bit of time to let it mellow, we finally had a sipper. Time to cut it back a bit and get it in the bottle. We're going to keep taking samples for GC-MS from the control barrel so that we can begin quantifying the acceleration due to the Symphony. Keep a lookout.

Symphony aged rum (6wks), on the rocks, ironically, in a NEAT glass. 

Symphony aged rum (6wks), on the rocks, ironically, in a NEAT glass. 

Let's make some beer - Single Malt Scotch Porter

I'm pretty sure that without homebrewing, Hertzbier wouldn't exist at all. When this idea started to take form, we wanted to go after faster fermentation for homebrewers, that was the goal. Wireless power made sense for carboys, since the idea of opening up the airlock to take a device in and out for charging violated just about every rule we knew of. We haven't explored the Symphony for homebrewing to near the extent that we anticipated, and that's a damn shame. Certainly aging on oak chips, dry-hopping, and barrel-aging are all opportunities for brewers to explore. Now that we've got some working prototypes in-house, time to try it.

Time to start testing.

Time to start testing.

By far my favorite homebrew creation to date has been the "Single Malt Scotch Porter". This beer features a smoked porter base and the addition of scotch-soaked hickory chips, and the scotch should be a peaty Islay (Finlaggan's from Traders being the best value for blending that we've found so far). We didn't have a goal for quantifying the impact on our homebrew (in fact, we'd love to hear from you about what tests and performance metrics would be of interest for future testing...please leave us a comment!), but we let the Symphony rip throughout the entire process, both in the primary and secondary. 


Get it out into the world...

Although far from being a market-ready product, some of the kind folks on the ADI Forums suggested that we reach out to a local distiller to build up some credibility and to start getting some feedback from an end user, and that's just what we did. Bill and his team at Liberty Call Distilling decided to give it a go, and we brought over our benchtop prototype to see what it could do.

Not exactly in a convenient form-factor yet...but it looked professional :-)

Not exactly in a convenient form-factor yet...but it looked professional :-)

In testing at Liberty Call...

In testing at Liberty Call...

Whiskey aging in 1G jars with spirals after 1 month - Hertzbier on the left.  

Whiskey aging in 1G jars with spirals after 1 month - Hertzbier on the left.  

After a month of aging, which felt like a lifetime (!!!!), we were thrilled to get an update from Bill and a picture as well. 

Hey Matt,

In a taste test with the standard, the Symphony enhanced whiskey is SOOO much smoother. It tastes better, easier to drink, less harsh, etc. [...]

 - Bill




Proof of Concept - 2L Barrels with Vodka

Turns out that getting enough wireless power to do something useful through a fair amount of distance (i.e. wood staves) isn't trivial...it took some work! Once we had a usable prototype though, we set out to see if we could show the world (er, ourselves) that all of our goals and assumptions could be validated with some actual spirit in some actual* barrels (we've since learned that 2L barrels are only "actual" to the smallest of home-crafter, but baby-steps!)

The barrels we used were 2L medium char vinegar barrels (large cork opening on the barrel head), and at this scale we could justify buying enough 80 proof unaged whiskey to fill a couple of these barrels.


We decided to let the experiments run side by side for a couple of weeks and we took small samples every day for pictures. It was easy to see the agitation within the barrel (which was the goal). Sampling at the end of the experiments (below) verified that we were on the right track.

2 weeks of aging moonshine (80 proof) in 2L (medium toast) oak barrels. Aged with Hertzbier on the left (no agitation on the right).

2 weeks of aging moonshine (80 proof) in 2L (medium toast) oak barrels. Aged with Hertzbier on the left (no agitation on the right).