How To Control Humidity For Ageing Homemade Cheese

One of the most important steps in cheesemaking is the aging, or maturation, process. Getting this stage right affects the texture, taste, and rind formation of your cheese. And the key to successful ageing? Humidity control. Different types of cheese need different humidity levels, so let’s explore the essentials for maturing homemade cheese to perfection.

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Why humidity matters for cheese ageing

Humidity influences how moisture stays in the cheese during maturation. If the humidity is too low, the cheese will dry out too fast, resulting in a cracked texture or a too-hard rind. Too much humidity, however, can encourage unwanted mould and spoilage.

Finding the right balance helps the cheese develop its desired texture, flavour and rind.

Effect of air humidity on cheese rinds

On a molecular level, air humidity affects the rind of cheese by controlling the movement of water molecules, influencing biochemical reactions, and impacting microbial growth. Here’s a breakdown of how humidity interacts with cheese at the molecular level:

1. Water molecule dynamics

Cheese contains water, fats, proteins and salt. When the humidity in the surrounding air is high, there’s a lower tendency for water to evaporate from the cheese’s surface. High humidity slows water movement out of the cheese, which keeps the rind moist and encourages the growth of specific moulds and bacteria.

In low-humidity environments, water molecules are more likely to evaporate from the cheese, leading to drying. This causes the proteins near the surface to denature and tighten, creating a harder and drier rind.

2. Protein and fat interactions

Humidity influences how proteins and fats on the cheese surface interact with each other and with water molecules. In a moist environment, casein proteins (which form a matrix in the cheese) can retain water, remaining flexible and preventing the rind from hardening too quickly. When proteins stay hydrated, they’re less likely to form dense cross-links, leading to a softer, more pliable rind.

In contrast, in low humidity, proteins and fats near the surface lose water, which increases the density of protein cross-links. This makes the rind harder and less permeable, which is desirable for certain hard cheeses but would hinder rind development in soft cheeses.

3. Microbial growth and metabolic activity

Cheese rinds are often home to various bacteria, yeasts and moulds. The availability of moisture from a humid environment supports microbial growth by allowing organisms to remain metabolically active.

Microbes, like Penicillium molds in blue and soft cheeses, require water to thrive and reproduce. When humidity is high, these microbes can grow steadily, breaking down fats and proteins and contributing to the flavour and texture of the rind and cheese.

In low-humidity conditions, the lack of moisture can reduce microbial activity, slowing down these biochemical processes. This affects not only the formation of the rind but also the development of complex flavours, since the bacteria and moulds responsible for flavour development become less active.

4. Salt and Ionic Interactions

Salt on the cheese surface interacts with water molecules, affecting osmosis and water retention. In high-humidity environments, salt ions attract water molecules, helping retain moisture at the surface and ensuring a more balanced rind development.

However, in low humidity, the water on the surface evaporates, leaving behind concentrated salt. This excess salt can inhibit microbial growth, resulting in a less complex rind. This is one reason hard cheeses, which benefit from a drier surface, can handle lower humidity without compromising their flavour.

The ideal humidity for different cheese types

Different cheese styles require specific humidity settings. Here’s a guide to the ideal humidity for soft, semi-hard, hard and blue cheeses.

Soft cheeses (80-98% humidity)

Soft cheeses like Brie, Camembert and Brillat-Savarin require high humidity. These cheeses have a high moisture content and a delicate white mould rind that needs moisture to develop well. Humidity of up to 98% allows this rind to grow while keeping the cheese interior soft and creamy.

Maintaining high humidity also prevents cracking in the rind. A cracked rind would expose the cheese to excessive airflow, affecting both texture and flavour.

Semi-hard and hard cheeses (80-95% humidity)

Semi-hard cheeses like Comté, Gouda, and hard cheeses like Parmesan need slightly lower humidity than soft cheeses. Aim for around 80-95% humidity for these types.

This lower humidity helps reduce excess moisture in the cheese and allows it to develop a firmer texture. A consistent, moderate humidity level will help form a smooth, even rind without cracking or drying out the interior too quickly.

Blue cheeses (90% humidity)

Blue cheeses such as Stilton, Roquefort and Gorgonzola need high humidity, around 90%. This humidity level keeps the cheese moist, enabling blue mould to spread inside, creating the distinctive blue veining.

Without high humidity, the blue mould may struggle to develop, and the cheese could dry out, resulting in an uneven texture.

How to monitor and control humidity for homemade cheese aging

To mature cheese at home, you need a reliable way to control humidity. Here are some key tools and tips to manage humidity for successful ageing.

1. Using a cheese cave or wine fridge

Many home cheesemakers use a wine fridge or dedicated cheese cave. These storage options allow you to set the temperature and monitor humidity levels, which is essential for cheese ageing. Place a hygrometer inside to check humidity regularly.

If your fridge doesn’t reach the desired humidity, try adding a bowl of water or using damp sponges to raise it. For reducing humidity, open the door slightly for brief periods to increase airflow.

2. Creating a DIY humidifying system

For those without a dedicated fridge, a simple plastic container can work for smaller cheeses. Place a small bowl of water or a damp cloth inside to increase humidity. Check daily to make sure your humidity stays steady.

A mini hygrometer can fit inside most containers to help track changes. Keep the container sealed tightly and adjust the water level or cloth dampness as needed.

3. Using ageing mats for surface moisture

Ageing mats help cheeses retain surface moisture and encourage even rind development. Mats made from bamboo or plastic are common, as they allow airflow while holding moisture on the surface. Mats are especially useful for soft and blue cheeses that need high humidity.

Remember to sanitise mats between uses to avoid unwanted mould growth.

Common challenges with cheese humidity

Humidity control can be challenging, especially in homes where temperatures and moisture levels fluctuate. Here are common issues and some quick fixes.

• Low humidity: If the cheese develops cracks or seems too dry, add more water inside the ageing container. A damp cloth or sponge can help boost humidity quickly.
• High humidity: If there’s excessive moisture or signs of unwanted mould, reduce humidity by removing any water sources, increasing ventilation or opening the container slightly for air circulation.
• Temperature changes: Changes in temperature can impact humidity. If your environment is inconsistent, consider moving the cheese to a more stable space or use a small fan to help with airflow and humidity control.

Different types of hygrometers

Here are some popular types of hygrometers suitable for ageing cheese at home:

1. Analog hygrometers

• Mason’s Hygrometer – Red Liquid IC736740: This traditional analog hygrometer includes a thermometer and is designed for accurate humidity measurement. It’s widely used in agricultural and food settings, making it suitable for cheese ageing where precision and durability are key.
• Brannan 12/413 Thermometer and Humidity Meter: This UK-made analog hygrometer is compact and reliable, featuring both a thermometer and a humidity gauge. It’s an affordable option for home cheesemakers who prefer a simple, battery-free device.

2. Digital hygrometers

• ThermoPro TP50: A compact digital hygrometer and thermometer with a clear LCD display. It measures temperature and humidity simultaneously, ideal for cheese ageing setups.
• Govee Smart Hygrometer: This model not only tracks humidity but also connects to a mobile app, allowing you to monitor conditions remotely. It’s great for those who want constant updates on humidity.
• Inkbird ITH-10: Known for accurate readings, this budget-friendly digital hygrometer is commonly used in home fermentation and cheese ageing. Its compact size is perfect for placing in tight spaces.

3. Smart Wi-Fi hygrometers

• SensorPush HT1 Wireless Thermometer/Hygrometer: This high-precision device connects to a smartphone app, offering real-time data and alerts. It’s highly rated for stability, accuracy and convenience, making it a great choice for serious home cheesemakers.
• AcuRite 06002M Wireless Temperature and Humidity Sensor: This Wi-Fi-enabled model allows you to check conditions via app, which is ideal if you’re monitoring cheese ageing in a remote cellar.

4. Hygrometer-thermometer combos with probes

• ThermoPro TP60: This hygrometer comes with a remote sensor and probe, allowing you to monitor humidity in difficult-to-reach spots. It’s suitable for deep cheese caves or containers where direct readings are tricky.
• Inkbird IBS-TH1: This model features a probe that can be placed directly inside a container, making it ideal for enclosed cheese ageing setups.

Final thoughts

Controlling humidity for cheese ageing takes practice, but the effort is worth it. With the right humidity levels, your cheeses can mature with the ideal texture, taste and rind. Start with a reliable hygrometer, track your humidity levels and make adjustments based on the cheese type.

Happy ageing, and enjoy the delicious results of your homemade cheese!

Cheese humidity table

References

Institut National de l’Origine et de la Qualité – https://www.inao.gouv.fr/

New England Cheesemaking Supply Co – https://cheesemaking.com/

Jonah Kincaid

Jonah is a a hipster, eco-warrior and slow food afficionado. Coming from a scientific background, Jonah has a particular interest in cheese science. And yes, he loves a good cheese pun!