Best Production Practices to Keep
Lead Out of Maple Syrup

Table of Contents

1. Why is Lead a Problem?
2. Where Does Lead Come From?
3. What You Can Do
4. The Future
5. Testing Your Syrup

Why is Lead a Problem?

Exposure of the public to lead has been a health concern for many years. Efforts have been made to reduce any level above typical maximum backyard levels including those products, such as maple syrup. Lead is a heavy metal that accumulates in blood and other tissues over time. The effects of lead are varied dependent upon the type and quantity of lead, the age of the person, and the route and duration of exposure. Large amounts of lead in the human body ultimately result in the decay of the nervous system.

Where Does Lead Come From?

Lead that is present in maple syrup can come from many sources. Minuscule amounts of lead may be present in sap directly from the tree, taken up by the roots from lead-containing soil. Lead may be present in the soil due to local rock composition or particles deposited in the soil from atmospheric pollution. Research has shown that maple syrup from soil-source lead has levels of lead far too insignificant for concern. What can cause problems and is the most obvious and preventable source of contamination is lead from equipment.

Maple syrup is an acidic substance (pH 3.4 - 6.6) that in the presence of oxygen with oxygen can react with many metal surfaces. Contact time of maple sap or syrup with any lead-containing metal should be minimized throughout all collection, processing, and storage. Lead can leach into the sap through galvanized equipment (made before 1994), most bronze and brass fittings, 50/50 solder (used for equipment before 1995), and terneplate (an alloy used in older equipment). Any contamination of sap is later amplified by the concentration of sap into syrup. Therefore, if the sap is contaminated by a trace of lead the evaporation process will greatly elevate it. A portion of the lead present in maple syrup is dissolved in the liquid and is not filterable, some is also associated with suspended particles and can be removed from the maple syrup with the sugar sand.

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What You Can Do

Whether you are from a legacy of sugar makers or a first time entrepreneur your best defense against lead is knowledge and preventative action. Having high levels of lead in maple syrup is entirely preventable. Depending on the size of your operation and the revenue that it creates, replacing older or outdated equipment while often desirable, is not always economically feasible. It is important to be aware of the condition of your equipment and how to operate it to minimize lead contamination. The following are some practices that can be followed to minimize the amount of lead entering your sap and syrup:

Collection

• Replace all old metal spouts (Figure 1) with stainless steel or plastic
• Gather sap from buckets daily, especially galvanized and tin
• Reduce or eliminate any metal buckets containing lead or lead solder (Figure 2)
• Replace bronze gear pumps (Figure 3)
• Replace any gathering equipment containing lead or alternatively paint surfaces with food grade paint including proper application
• Use food grade tubing. Any metal fittings coming in contact with sap, replace with plastic or stainless steel

Figure 1. Replace old metal spouts

Figure 2. Galvanized bucket with lead solder

Figure 3. Bronze gear pump

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Boiling

• Purchase lead free pre-heaters
• If your pans have lead in the metal or solder - do not clean pans to a bright shine with a strong acid based cleaner (exposes new metal for sap to react with)
• Replace any brass or bronze fittings
• Minimize the time that sap resides in the evaporator (Figure 4)
• Remove sap from pans if there are prolonged periods between boilings and flush pans with water
• Purchase only lead-free solder and stainless steel pans (Figure 5)
• Make sure any repairs are done

Figure 4. Evaporator with tin pans and lead solder

Figure 5. Tin pan with lead solder and rust

Filtering

• Filtering is very important!
• Use clean, unscented filters
• Never filter syrup into old milk cans (Figure 6)
• Only filter syrup into food grade containers
• Use orlon/felt filters and/or a filter press
• Use filters with a small micron size
• Use filters in good condition

Figure 6. Never filter syrup into old milk cans

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Sap Storage

• Replace all galvanized tanks that are corroded or damaged immediately
• Purchase only stainless steel, glass lined, or food grade plastic storage tanks
• Use only food grade paints on tanks using proper application procedures

Syrup Storage

• Ensure that all your syrup is batch coded
• Never store syrup in corroded containers/drums (Figure 7a and 7b)
• Don't use containers/drums with unusual dents
• Ensure the container/drum is clean and free of odours

• Never use old containers - like milk cans. Use stainless steel, glass lined, or food grade plastic barrels if possible

Figure 7a and 7b. Corroded storage barrels should be replaced

The Future

As concern over the quality of food increases, the sugar maker must make it their mission to ensure that the maple syrup the customer purchases and enjoys is pure. With all producers, large and small, working together to produce and promote a quality product the Maple Industry will continue to thrive.

Testing Your Syrup

The only way to know the lead content of your maple syrup is to have it tested. It is recommended that you have your syrup tested three times throughout the sugaring season to ensure consistent quality of your syrup (Figure 8).

Figure 8. Sap should be tested for lead three times throughout the sugaring season to ensure consistent quality

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