Improving Wine Quality Through Sanitation

The bustle of crush can create a breeding ground for dangerous microorganisms

by Peter Mitham
winery cleanliness
Few wineries can appear as pristine as the one on the left, but proper sanitation is key, especially during crush, when wine grapes, juice and equpiment are constantly being moved.
Penticton, B.C., Canada—We’ve probably all had the experience, either in our own wineries during crush or when visiting other people’s premises: The stickiness of grape juice and must on floors, railings and a general sense of the winery being closer to an actual workshop than something in Architectural Digest or the glossy tourist brochures.

But if there’s stickiness, there’s sugar; and where there’s sugar, there’s food for bacteria, flies and a vinegary atmosphere. And vinegar isn’t something most of us want associated with wine.

“My first line of defense is always sight, smell and touch. If it feels slimy, if it smells bad and it looks bad, then chances are it is bad,” said Gordon Taylor of Daven Lore Winery in Prosser, Wash., during a presentation to winemakers at last week’s conference of the British Columbia Wine Grape Council.

During a half-hour presentation about how to keep things “clean and mean” in wineries, Taylor laid down the law: “There’s no reason for it, you just have to keep those things at bay,” he said. “It’s nothing different than good management practices.”

Recipe for trouble
Microorganisms move from becoming a dormant part of a winery’s ecosystem to a problem with very few ingredients, many of which are activated by the bustle of crush: nutrients, ambient temperatures, moisture and time.

The warm temperatures that make for a comfortable harvest are also appealing to bacteria and other critters, which will start increasing in number if spills and damaged fruit are not removed. With time and no cleaning, conditions are ripe for problems to start.

“We all know that we have fruit flies in our winery in the fall,” Taylor said. “But if you have biblical proportions of fruit flies, it’s not clean enough.”

Three simple procedures can help manageable problems from becoming plagues: cleaning, regular sanitation and sterilization.

“Cleaning is the removal of debris off the surface; you have to do that one first. Sanitation is the reduction of unwanted organisms. And then sterilization: Basically, let God sort them out, we’re going to eliminate everything,” he said. “But if you haven’t cleaned something up front, and you’re sterilizing some filth that’s lying on top of your tanks, you’re not going to have it clean. It’ll just cover the surface, then some piece will break off and you’ll have problems…98% clean is still 100% dirty.”

Design for cleanliness
One of the basic avenues to ensuring good winery hygiene is good design (a factor considered by many wineries in Wines & Vines’ regular Technical Review features).

Adequate lighting and ventilation, specific areas for cleaning barrels and building systems that deliver reliable hot water are key, as are subtle elements such as sufficient slope to the floors so that liquids flow toward the trench drain rather than pooling or—worse—toward walls, corners and crevices where they can harbor micro-organisms.

“If you can keep your trench drain clean, you’ll drop your fruit fly load considerably,” Taylor noted.

The winery floor isn’t the only place where the flow of liquids—or their pooling—is an issue.

The downside of gravity flow
Among the hotspots Taylor singled out for special consideration when it comes to ridding a winery of bacteria are gravity-flow systems. Since they’re designed to carry materials downward, Taylor reminded winemakers that gravity-flow systems need to receive vigorous upward cleaning.

He advised growers to have a clean-in-place system at the foot of the line that can provide adequate turbulent flow up gravity-fed pipes, sufficient to lift debris and residues off the inside (he suggested a flow of 24-34 gallons per minute through a 1-inch pipe).

“Push up the line and clean it because the top of the pipe will always be dirty,” he said. “No matter how much chemical you throw down a gravity system, it will always be dirty because you can’t clean the pipe—it’s going to be open on top.”

Similarly, Taylor warned against dead legs in piping (places where liquids can stagnate for lack of adequate pressure). This frequently occurs when smaller pipes flow into larger pipes, with a consequent loss of pressure as cleaning water enters the larger channel. The flow of water is inadequate for cleaning the larger pipe, resulting in accretions of debris, residues and bacteria.

A little elbow grease
Perhaps the biggest risk to winery hygiene is inadequate cleaning, and the accumulation of nutrients and then bacteria in places such as valves, locks, the threads of connections, unpolished welds and the undersides of tanks, barrel racks and other areas that may come in contact with wine but are seen as secondary to the actual making of wine.

Hot water is handy even for simple tools like the wine thieves used for drawing barrel samples; dipping them in boiling water between barrels can limit the spread of contamination between barrels.

“Be proactive in the cellar hygiene, don’t be reactive. After something’s spoiled in the barrel, it’s too late to be good at it,” he quipped, adding: “Better winery sanitation can only improve your wine quality.”

The result is lower overall risk and better margins on operations as the cost of addressing problems falls and reputation for quality increases.

“Chances are the wines are going to be good when the facility’s nice and clean,” he said. “And it sets benchmarks and goals for the employees.”

Posted on 07.30.2013 - 08:38:31 PST
A great option for easy sanitation is a spray bottle of high proof reverse osmosis wine distilled to 170 proof. A common misconception is that you need a DSP to have spirits on premises; not true. All you need is to be a bonded winery.
Jack Jacoby