Copper is medicine for a bad ferment!

Whiskey making: the procedure If we exclude grain handling and aging, traditionally, whiskey is made in three steps:

1. Mashing (converting starches into fermentable sugars by using enzymes);
2. Fermenting (converting the fermentable sugars into alcohol with yeast);
3. Distilling (concentrating the alcohol and harvesting the right flavors).

In order to create the best possible whiskey, both in terms of yield and taste, all steps need to be optimized. The end product is the sum of how the various parts are performed. If mashing is sub-optimal, the major loss you face, as a craft distiller, is yield. You will create less alcohol. A failing fermentation will, above all, have impact on flavor creation. That's because over 80% (as a rule of thumb) of taste molecules are made during fermentation. Bad distilling procedures can affect both yield and flavor composition of your new make spirit. Whiskey making: historically Historically, whiskey was made in small batches. Small mashes are easy to handle. Small ferments do not generate a lot of heat. Small, copper stills were the norm, because copper was available, affordable, and bendable. In the 1870's the industrial revolution found its way into the distilling industry. A lot of the whiskey production became bigger and more centralized. A declining number of remaining distilleries that, each on their own, saw a steep increase in production output.

Small batch traditionally allows for good control and therefore good whiskey ...

Batch size growth associated problems As distilleries grew bigger, mashing basically scaled up from small batch to big batch, and yield didn't suffer. Fermentation scaled up from small batch to big batch as well, and this did created a major problem. Fermentation creates heat, and the bigger ferments created more heat. The warmer fermentations stressed out the yeast and produced multiple unwanted flavor compounds in the base beer, of which sulfur was (and is) the most important. In short? As distilleries got bigger, mashing didn't get compromised, but fermentation did. Yield didn't suffer, but flavors did. Interestingly enough, it took a few more decades for distillers to realize they actually had a problem.

Bigger, uncontrolled ferments generate bad flavors that copper catalyses ...

Houston, we have a problem! In the 1960's new metallurgic innovations found their way into the distilling industry. As growing distilleries needed bigger stills, traditional copper stills were replaced with more modern stainless steel set-ups. And guess what? All of a sudden the whiskey they produced had bad, sulfur associated flavors in them! What had happened, was the following: copper reacts with sulfer. The traditional copper stills had managed to polish-up the bigger, overheated, sulfur-rich whiskey beer! Copper, it turned out, was a really good medicine for a bad ferment.

With SS stills, sulfurs no longer got catalyzed, and bad ferments got exposed ...

The traditional solution The switch from copper to stainless steel stills brought to light a major problem: bigger ferments created off-flavors. The solution the industry rallied toward, was to switch back to copper stills. The copper catalyzed the sulfuric compounds to below the taste threshold, and the problem was solved. Or wasn't it? Bigger ferments, left unchallenged, grow too hot, stressing the yeast into making multiple unwanted flavor. Sulfur is the most significant of those and copper does a good job at cleaning up these sulfuric flavors, and at hiding the poorly managed ferments.

So the distilling industry switched back to copper stills ...

Compromised solution Using copper stills, to counter bad ferments, is a treatment of effects, not a root cause solution. By allowing for non-optimized whiskey production via copper stills, the following set of new problems occurs:

1. Uncontrolled, overheating fermentations create more bad flavors than just sulfur;
2. The copper clean-up during distillation does not polish-up all of those;
3. Copper stills oxidize, creating copper contaminated whiskey;
4. Copper stills need extensive cleaning, making for longer working days;
5. Due to oxidation and cleaning, copper stills need to be replaced in 10 to 15 years.

Even though copper stills are a medicine for bad ferments, they are not the ultimate solution. Bad ferments create bad flavors, and copper does not counter all of them. More so, copper is a heavy metal that is toxic to humans. Due to the reactive qualities of copper, the distillation equipment needs extensive cleaning. This cleaning, as well as the general levels of oxidation, severely hamper a copper still's longevity. The iStill solution That's why we started proposing a different approach. Here it is. Let's call it the iStill solution:

1. Mash in a controlled environment, to achieve maximum yield;
2. Ferment in a controlled way, to achieve maximum flavor;
3. Distill in a controlled way, to achieve maximum yield and flavor.

Our iStills are designed to mash with 0.1 degree temperature tolerance. This gives the distiller the opportunity to maximize yield, which helps optimize production quantities. During fermentation, our technology brings temperature, pH, and SG under control. This ensures that the distiller maximizes the desired flavor development. Finally, the iStills have perfect control over the distillation process. This helps the distiller in optimizing both flavor profiles and yield in the most efficient and repeatable way.

iStill gives you the control to make better whiskies ...

Design choices Because we optimize fermentation, the creation of undesired, bad flavors is minimized. As a result, we do not have to build our stills out of copper. This way, we can deliver a still that is easy to clean, does not cause copper particle contamination in your spirits, and has tremendous longevity. But if you decide you are going to do your fermentation quick & dirty anyhow, well, please know we have copper waffles that you can insert at the bottom of the column. It takes less than a minute to put them in place. It takes less than 10 seconds to take them out, when the run is done. They have the same surface area as a complete copper column, without the hassle.

iStill copper waffles: well-used ...

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