The Cleaning Power of Steam

Smog City Brewing Founder and Brewmaster Jonathan Porter uses a steam generator for many tasks around the brewery, from deep-cleaning barrels to dealing with pesky floor drains and de-stickering kegs and other equipment.

John M. Verive Dec 14, 2016 - 9 min read

The Cleaning Power of Steam Primary Image

A lot of hardware goes into making beer, and enterprising homebrewers are skilled at cobbling together the gear they need, whether it’s a cooler mash tun or a hopback built from plumbing parts. Once a brewer goes pro, the ability to get the most out of limited resources becomes even more important.

Working on the edge of their production capacity with tight margins and growth can compound these challenges. The pains that come with expansion provide the resourceful brewer with ample problem-solving opportunities, and any incremental improvements to process and efficiency can help them make better, more consistent beer. When Smog City Brewing in Los Angeles took over a warehouse near their production brewery to house a growing collection of wine barrels, Founder and Brewmaster Jonathan Porter needed to balance making the regular production beer that keeps the lights on in the brewery with all the additional tasks required to process and fill all that oak.

“Barrels aren’t cheap, but all the labor they need is the bigger investment,” Porter says. “There’s a lot of money in that oak,” he says, gesturing toward the barrel warehouse, “and it’s slow to return any revenue.”

Looking for a way to both protect his investment into all that oak and streamline the ingress of newly acquired barrels into Smog City’s barrel room, Porter turned to an old technology that’s become popular with winemakers: steam. The Swash Deluxe, a portable steam generator from ARS Enterprises, creates high-pressure, high-temperature “dry steam,” and the cast-bronze attachment known as a Bordeaux wand is built to cleanse and condition oak barrels.


The 350-pound machine looks like a cross between a pushcart and a Star Wars droid, and the wheeled boiler can be moved to the barrels that need to be cleaned. It requires 220-volt power and a waterline to create the culinary-grade steam that’s free from additives and has very low mineral content. A specialized steam hose connects to the outlet ball valve, and various accessories can be clamped onto the hose. The Bordeaux wand is a meter-long brass baton that emits the steam from a number of nozzles along its length; the wand is inserted into the bung of an empty barrel, and the dry steam generated by the boiler can penetrate the porous oak to clean the wood.

Once a barrel has been steamed for about five minutes, it can be deep cleaned by removing the wand and immediately sealing the bung. The barrel is then left to cool, and the partial vacuum created as it cools down pulls what Porter calls “the gunk” from the porous oak. A quick roll and dump of the cooled barrel produces a liter or two (compared to the sixty liters, or more, that would normally be used to fill and clean a barrel) of murky fluid that’s saturated with the residues of past inhabitants, tartrate crystals left from winemaking, and other contaminants. Getting better results with far less water is an important consideration, especially for the brewery in drought-choked California. The steam pressurization is also an effective way to check for leaks in a barrel that doesn’t require the vessel to be filled with water—another way the steam generator helps the brewery save water.

“I hate watching water go down drains,” Porter says, and he wants to keep cutting down on his water use. “We’re looking for even more ways to use [the steamer] around here.”

The steam treatment will also swell the staves of the barrel, helping to prevent leaks and reducing the risk of a barrel drying out too much. This is important to Porter because he can’t always schedule the arrival of a shipment of barrels, and with a tight production brewing calendar, it can be difficult to coordinate a brew destined for barrels for when fresh oak arrives at the brewery or a batch of barrel-aged brew is packaged. Instead of filling an empty with water to prevent drying out—and risk losing the character of a freshly dumped barrel—Porter can steam a barrel and store it until he’s brewed something to fill it with.

With more contact time, the high-temperature, high-pressure steam can also be used to control the microbial populations of a barrel. This is especially important to winemakers who are buying new oak barrels for upwards of a thousand dollars each and who are extremely concerned about Brettanomyces infections. While the bugs are an important part of Porter’s barrel-aged wild ales, he likes to have full control over which microbes are residing in his oak inventory. He used to decommission the wine barrels that turned acetic or created a flavor profile that’s outside of his vision. “They got pulled from rotation and turned into furniture,” he says gesturing to a pair of side tables in the tasting room. “It sucks. We paid a lot of money for those barrels.” With the Bordeaux wand, Porter can push superheated steam deep into the barrel’s wood to kill the unwanted guests. The barrel can then be re-inoculated with the house culture and reused to make beer instead of seating in the taproom.


Porter says the Swash has been like getting a new hammer and not having enough nails—he just wants to steam everything. The package he purchased also came with a gun attachment that can be used to jet the high-temperature steam pretty much wherever. It’s become a helpful tool for the unending cleaning tasks around the brewery. Porter finds it especially helpful for dealing with pesky floor drains and de-stickering kegs and other equipment.

“It’s kind of a toy, but we’re finding a bunch of ways to use it,” he says while spraying a burst of steam into the drain at the base of the brewhouse. “It’s really pretty fun.”

Homebrewing Application

Ambitious homebrewers looking to condition incoming barrels probably don’t have access to a dedicated steam generator, but they can use many of the same ideas to prepare their wood. “Filling a fresh barrel with 180°F (82°C) water is the first step,” says Kristofor Barnes—a longtime homebrewer who’s opening a production brewery in Los Angeles. He’s been experimenting with wood aging his brews for years and says prefilling will reveal any leaky spots, help rehydrate the barrel, and prevent it from drying out any further. The hot soak will also help swell dried-out staves to seal any leaks. You may have to top off the barrel with hot water a few times if you do have leaks, but Barnes says that’s better than discovering that a barrel leaks when you’ve filled it with beer.

Home brewers looking to harness the power of steam to deep clean and sanitize barrels will need to get extra creative and maybe a little daring. There are not any readily available products or tools for these tasks that are within the reach of the average homebrewer, but since when has that stopped creative and resourceful brewers accustomed to beverage-cooler mash tuns and kegs cut into kettles? Some exploration into using steam in a home brewery turns up concepts and plans for steam generators built from modified pressure cookers and small-scale electric boilers for both cleaning and heating of boil kettles and hot liquor tanks. There’s no reason that intrepid and handy-at-home engineers can’t cobble together a DIY steam setup for barrel conditioning, but high-temperature, high-pressure steam can be dangerous, so this is not a project to approach cavalierly.

For more details about using barrels in your homebrew operations, check out “Prepping Used Barrels for Aging Beer”.



In addition to the Swash Deluxe from ARS Enterprises, there are a few other portable steam generators specifically targeting the alcoholic beverage industry:

Vapor Box Steam Generator, distributed in the United States by The Vinter’s Vault

LG 10-30C, from Electo-Steam

AaquaSteam, from AaquaTools

Reimers Model RB, from Reimers Electra Steam, Inc.