Smokehouse and Smoking Guidelines for Cheese and Cheese Products

Introduction

Smoking gives cheese a characteristic taste and look. To achieve this, processors use a smoker to create smoke outside the smokehouse and direct it inside the smokehouse, where it passes over the cheese.

Under Ontario's Milk Act, smoking cheese is considered to be a form of processing a milk product.

As a cheese maker, you should be aware of the food safety risks associated with the smoking process. These include:

• contaminating the cheese with cancer-causing substances if the cheese comes in direct contact with heavy smoke
• contaminating the cheese with harmful bacteria if you do not follow good manufacturing practices or the smokehouse is not made of materials that can be properly cleaned and sanitized.

Smokehouse/Smoking Requirements for Cheese and Cheese Products

1. Locate the smoker/smokehouse inside a dairy plant licensed under the Milk Act.
   
   Dairy products should never be handled or processed in a non-licensed facility because they could become contaminated through:
   • incompatible activities such as processing meat, processing other foods, or smoking meat products
   • inadequate sanitation
   • improper handling procedures that contaminate the product with dust, foreign materials or microorganisms.
   It is not acceptable to smoke cheese in a smokehouse located within a provincially licensed or federally registered meat plant.
2. Avoid incompatible activities that may contaminate the dairy product. For example, don't locate the smoker/smokehouse within the following areas:
   • milk-receiving bays
   • other areas where raw milk is handled
   • the "make room" of a cheese processing plant.
   The smoker/smokehouse needs to be located in a finished product area. It needs to be physically separated from incompatible products and activities or separated in some other effective way to prevent contamination.
3. Enclose the smoker/smokehouse in a separate compartment or room.
   
   Because the smoking process creates strong odours, the smoker/smokehouse should be enclosed to stop the odours from affecting the quality of products in other areas of the dairy plant.
   
   The inside of the compartment/room needs to be designed to:
   • minimize the risk of food contamination
   • make it easy to keep the smoking process sanitary
   • be easy to clean effectively.
   If dust, dirt or condensation build up, they can contaminate the product. The smoker/smokehouse needs to be designed, built, finished and maintained in a way that prevents this.
4. Make sure all the surfaces and racks in the smoker/smokehouse are made from materials that are:
   • corrosion-resistant
   • smooth
   • waterproof
   • easily cleaned
   • able to withstand repeated cleaning and sanitizing
   • approved for use in a food plant
   How effectively you can clean your smoker/smokehouse depends on the design. Sharp corners and angles are difficult to clean. Because racks directly touch the cheese, they need be made of stainless steel or corrosion-resistant material. You need to be able to keep the racks sanitary so there are no microorganisms on them that could contaminate the cheese.
5. Make sure the smoker/smokehouse has enough ventilation to exhaust the smoke.
   
   You need to be able to exhaust the smoke so that airborne contamination such as steam, condensation, dust or odours don't affect the quality of products in other areas of the dairy processing facility.
6. Make sure the exhaust duct is designed to stop rainwater or pests from entering the smokehouse. When the duct is not being used, it needs to be sealed (for example, with a damper or baffle).
   
   Exhaust systems need to be easy to clean, and they need to be kept clean.
7. To create the smoke used in the smoker/smokehouse, choose combustible materials that will not affect the safety of the cheese or cheese products.
   
   You can use:
   • hardwood
   • hardwood sawdust
   • vapourized liquid smoke created from hardwood or hardwood sawdust.
   Make sure the material you use is certified as food grade. Store it and handle it properly to minimize the risk of contaminating food products.
8. Control the temperature of the smoke to protect the cheese from polycyclic aromatic hydrocarbons (PAHs).
   
   Small particles in smoke may carry PAHs. PAHs are a food safety concern because many of them are known or suspected to cause cancer. To reduce the risk of creating PAHs, keep the smoke temperatures low.
   
   Temperature control is extremely critical for the cold smoking process. Place the smoker outside the smokehouse, smoking chamber or processing oven. To keep ignition temperatures below 350-375°C, make sure the moisture content of the hardwood sawdust or chips is at least 30%. Also, keep the smoke vapour below 29-32°C to make sure that the cheese does not soften and lose shape or start to oil off.¹
9. Write down your processing procedures. For each batch of cheese you process, record:
   • The date
   • The lot identifier
   • The processing time
   • The temperature
   • The cooling time
   • The type of combustible material you used.
   Keeping track of these things will help you ensure product consistency. Update your procedures as required.
10. Make sure you have a written cleaning and sanitation program.
    
    Since the smoking process is performed on finished cheese product, use cleaning chemicals that can remove smoke residues without leaving chemical residues that could contaminate the next lot of cheese. Generating smoke creates residues that are difficult to clean using typical dairy detergents. However, the detergents you use should still be approved for use in a food plant. Carefully evaluate your cleaning and sanitation program to make sure it is effective.

Training Programs

All plant employees should be trained to make sure they understand the importance of their role in the smokehouse and how it can affect the safety of the food they are preparing and the health and safety of people who eat it.

Accessing Smoking Services from a Licensed Dairy Plant

If you do not have your own smokehouse, you need to make sure that the smokehouse that handles your cheese meets the following requirements:

1. It is located in a dairy plant licensed under the Milk Act.
2. It meets the conditions outlined in this guideline. Examine the facility's written program to verify that:
   • the requirements for smoking and smokehouses are met
   • records are kept
   • the right corrective steps are taken if deviations occur.
3. It has a written training program for employees that includes appropriate training in personal hygiene and hygienic handling of food. The program is enforced, and it is updated at appropriate intervals. The training should reflect how complex the manufacturing process is and how complex employees' jobs are.

You also need to make sure that:

1. Both your plant and the smokehouse operator have documented procedures and records demonstrating that both facilities have control of the chain of custody. As the cheese manufacturer or the owner, you need to have a written process control procedure to make sure that you can track each lot of cheese for traceability.
2. The vehicles used to transport the cheese to and from the off-site smoking facility are designed, built, maintained, cleaned and used in a way that prevents food contamination.
3. The cold storage facilities where your cheese is kept are designed, built, maintained, cleaned and used in a way that prevents food contamination.
4. Programs to check the effectiveness of cleaning and sanitizing are documented and implemented.
5. Finished product that needs to be kept at a specific temperature is transported and stored at that temperature.
6. Records are kept that demonstrate the cheese has been transported and stored at the right temperature for that type of cheese.
7. You have good microbiological control over your products. It is your responsibility to demonstrate that the safety of the product has been maintained.

Resources

1. Wendorff, W.L. Smoked Cheese, A comprehensive guide for cheesemakers. Wisconsin Center for Dairy Research, Univ. of Wisconsin-Madison.