Ultimate Guide To Mold In Wine Cellars

Why does mold grow in wine cellars?

Wine cellars conjure up images of vintage wines, Italian Chateaus and rolling vineyards. Sadly they also often conjure up mold. Mold and mold spores thrive in dark, damp places and cellars provide a perfect mix of dark and humid. Thus, creating a breeding ground for mold. Cellars are humid and often kept so to maintain the integrity of both the cork and wine. It is essential to find the right balance of humidity to allow for optimal wine conditions and limit mold growth. 

For new builds, the wine cellar builder you work with will be able to provide expert advice. They will guide you through the design and build to ensure a cellar perfect for wine, not mold. In older buildings, it is worth making sure the cellar has been maintained. Maintenance including making sure it's ventilated, sealed and set up to prevent the growth of mold and dampness. It's worth calling on the expert knowledge of a wine cellar builder to help plan what updates and maintenance are needed to keep historical cellars up to date with modern technology including air cooling and ventilation systems. 

It's worth checking the foundation and walls to see if there's any water damage or water seepage within or near the cellar space. Both these common issues can contribute to mold growth in your cellar.  Ensure the air in the cellar is well ventilated and controlled to stop the growth and buildup of mold in the cellar space.  A cellar needs to be sealed and separate from the rest of the building to ensure the humidity required does not affect elsewhere. 

Is mold in a wine cellar a bad thing?

Wine cellars often bring to mind French wine caves with racks of wine covered with centuries of history (i.e. dust and mold). A bottle removed reveals the signs of age and vintage, its white-label slightly aged and marked with mold spots. While most experts agree some slight mold damage on a label can be a sign of aged distinction. Some argue mold can add flavor and notes to the cellar; there is a line between a touch of mold and an excess of mold. 

Small amounts of mold can be acceptable, especially in historic cellars. For a new build, ideally, you want no mold to occur. Your wine cellar builder will design and build the cellar with features to allow optimal wine preservation without excess mold growth occurring.  While it's hard to eliminate all mold, you don't want your cellar to become a petri dish for the next issue of Scientific America.

What types of mold are common in a wine cellar?

When dealing with mold growth, it is vital to establish what type to ensure the cleanup and prevention are as effective as possible. Generally, mold falls into three categories:

Allergenic: These molds cause allergies like sneezing, coughing or breathing issues. 

Pathogenic: These cause further health issues for those with illness.

Toxigenic: Those that produce a toxic substance are often called "toxic mold" and can cause severe damage. 

The most common molds seen in cellars are

Alternaria: an extremely common mold both inside and outside the house. This allergenic mold causes common reactions like sneezing and is often found in damp areas like sinks or cellars. Velvety texture with green-brown hairs. 

Aspergillus: an allergenic mold that often appears yellow in color and forms in water damaged areas or humid areas. This can become more toxic if not found and treated in time. 

Chaetomium: often found in water-damaged drywall it's usually found by the distinctive musty odor. This brown colored mold often forms in rope shapes along walls and surfaces. It's an allergen and can cause significant health problems if exposed over time. 

Cladosporium: found inside areas like wooden cabinetry and floorboards. This is often a problem in cellars due to the damp, humidity and wooden wine racks. Another allergenic is it can cause a variety of respiratory problems. Olive green or brown in color with a suede-like texture. 

Stachybotrys (black mold) this toxigenic mold is often called black mold. It thrives in damp, wet areas with high humidity levels, which makes it a cellar problem. Dark green or black with a slimy texture it can cause severe health problems. 

How can mold be removed from a wine cellar?

First, remove the wine, it is delicate and temperamental, and none of the options for removing mold will help the vintage. Remove it or if that is not feasible, ensure it is adequately protected from any mold treatments about to occur. For simple quick solutions, there's a range of Hydrogen Peroxide or Vinegar solutions you can DIY. Wipe down all surfaces with this solution and give it adequate time to dry and air before putting the wine back. If your wine is in a cabinet within the cellar, make sure you clean any seals and around any doors.  

For mold occurring on concrete or stone walls, it is best to repeat this process a few times to remove all mold.  If it is a large area of mold, consider working with a professional to make sure all the mold is removed and areas are thoroughly cleaned. Once you've removed the mold, it is essential to make sure you make changes to stop it from re-occurring. Speak to a wine cellar builder about optimal humidity and conditions to ensure mold won't grow back over time. 

 How can an air conditioner or cooling system help with mold? 

First, ensure your cellar remains at optimal temperature, and the humidity doesn't creep up. An air-conditioner or cooling system can help. Planned with a wine cellar builder, you can create a cellar that prevents mold from growing out of control while still staying humid enough for optimal wine storage.  It is important to get the correct cooling system or air-conditioning unit for your cellar as each cellar's size, location, and specifications will require different cooling needs.  

As well as allowing for temperature control, cooling or air-conditioning will enable you to properly ventilate the cellar, thereby reducing chances of mold growth and build up. While it sounds the opposite of the humid temperature needed for cellars, a cooling system allows you complete control over your cellar no matter the season or weather.  

Happy drinking!