Mashers, fermenters, and stills … up until now every Craft Distiller knew he had to acquire one, two, or a few of each of them. Up until now? Yes, until we released the iStill NextGen line-up that can mash, ferment and distill in any combination the Craft Distiller sees fit.
This iStill Blog post will not talk about why one boiler, from now onwards, suits all stages of the spirits production process. I think I made a good case about that a few blog posts ago. This iStill Blog post will talk about why the old designs are far from optimal. It will also explain the design principles behind the NextGen boiler, and how we came up with a no compromise optimal solution.
Old style mashers, fermenters, and stills
Old style mashers, fermenters, and stills have very different boiler designs. Why? Let’s dive in deeper.
Mashers in general are rather wide. The reason is that a wide masher can create a thinner grain bed. That’s good if you want to sparge beer. For a distiller that doesn’t mean shit, but anyhow, mashers are wide and relatively low for breweries … and that’s why the ones Craft Distillers use are wide and relatively low too.
Now onwards to fermenters. In general, old style fermenters are of a more narrow and high design. That way you can use total ceiling heigth. The old style Craft Distiller probably had a still with a huge, tall, and inefficient column … so he needed a high ceiling. In order to maximize floor space use, our industry ended up with narrow, tall fermenters.
Old style stills have huge, heavy, and very inefficients columns. Because of column weight, boilers have to be relatively narrow to prevent caving-in issues.
So … is the old style any good?
The short answer is: yes, no, and no! But let me elaborate.
A masher, to suit the modern Craft Distiller, has to be relatively wide. The reason is that a wider design creates more surface area. This surface area may be used at the bottom for direct heating and at the top for a more gentle boil. Direct heating leads to more taste formation, where a more gentle boil allows you to fill your masher to a higher degree.
The answer to the question if the old style of designing mashers is any good can be answered by “yes”. Not because we need to sparge. That would be ashame, since fermenting and distilling on the grain brings over much more taste, but because it allows for better direct heating and a bigger total mash volume.
Fermenters are high and narrow. The reason is because old style stills have huge, tall, and inefficient columns. “If the ceiling height is there for that column … let’s make our fermenters as high as we can as well”, has been the design principle behind fermenters over the last century. Is that design principle any good? No, it isn’t. And it isn’t for three reasons:
- Modern, 21st Century columns do not have to be that high;
- If you migrate from a round to a square fermenter design, you can use floor space much more efficiently;
- Water pressure stresses yeast.
I will zoom in on the last point: yeast likes to work in a stress free environment. And pressure adds stress. The less pressure yeast has to deal with, the better it performs. A water column of like 4 meters means that the yeast that is situated at the bottom of that old style, and very high and narrow fermenter, has to deal with 4,000 kilo’s of water pressure. That’s not ideal. And that’s why the answer to the question if the old style fermenter design is any good has to be “no”!
Old style stills have relatively narrow and high boilers to prevent caving-in issues from their tall and heavy (did I mention inefficient already?) columns. But that is a compromised solution, since distilling benefits from wider, less high boilers.
A wider design has a more gentle boil. A gentle boil allows for a higher filling grade. A more gentle boil also creates a more stable gas bed above the liquid that allows the column to do its work of harvesting and separating the right alcohols and associated congeners with more ease.
A wider distillation boiler design also allows for easier direct heating. And direct heating, while distilling, enables the Maillard Reaction (a taste cascade) to take place. All Craft Distillers should take advantage of that reaction: that with directly fired stills you can get over 20% more (and better!) taste.
The NextGen Revolution
A modern masher should be relatively wide. A modern fermenter should be relatively low (and wide) to minimize yeast stress. A modern still should be relatively wide too.
And that’s exactly what we did, when we designed the iStill NextGen! The NextGen design is relatively wide and low, so it creates optimal mashing, optimal fermenting, and optimal distilling conditions.
Since mashing, fermenting, and distilling are all about heating up and cooling down … since mashing, fermenting, and distilling are all, in an ideal world, about heating up and cooling down in a relatively wide and low boiler … we give you the iStill NextGen boiler.
We call it “NextGen”, because it allows the Craft Distiller to take the next step, and migrate to that ideal world, where he can decide to mash, ferment, and distill in one (1) optimized unit.
I firmly believe that, by desiging the NextGen equipment, iStill has changed the Holy Trinity of mashing, fermenting, and distilling and finally turned it into a Holy Unity.
Holy crap, we did it again! iStill has changed the face of Craft Distilling once more!