What is Maple Syrup Made of and How is it Produced?

By Andrew Campbell

Our farm tour today takes us to the woods, where you wouldn’t think you would find a farm. But here in Canada, mostly in the provinces of Ontario and Quebec, you will find maple syrup farms. Lawrence McLauchlan is going to tell us all about his operation here at Fort Rose Farm and how he and his family tap the sugar maple trees to harvest their sap to make the iconic Canadian maple syrup.

Maple syrup may scream Canada, but do you actually know how it’s produced? Let’s find out with a tour into the sugar bush, as it is so elegantly nicknamed, where maple trees are tapped for their sap. And then the real work begins to transform that sap into the sweet and sticky syrup we all want on our pancakes. So join the tour with the McLauchlan family to see just how maple syrup is farmed.

Can you tap other kinds of trees other than the sugar maple?

You can tap other maples, but sugar maples are the best. They have great flavour, the highest sugar content and best yield. They also have the longest sugaring season. On average, sugar maples will produce for 20 days over the 6-week season and produce about 1 litre (about 4 cups) of syrup per tree.

When I was a kid, we used buckets and I remember hauling them in full of sap with grandpa. He thought that was a great job. And as a kid, we thought it was a great job too. You don’t use buckets anymore. Tell us about your new system.

We had a lot of buckets when we were younger but now we have switched to a more modern method with a pipeline and a vacuum system to collect and gather the sap. All these small blue lines travel from tree to tree. On the end, inserted into the tree is a spile (a kind of spout) that creates a bit of vacuum that wicks that sap away when it drips out of the hole. It is very simple. When we get a little bit of frost at night and then the sun shines in the day, sap starts to flow through the lines to our tank.

That means you’re pretty weather-dependent to make sap.

Oh yes. Mother Nature is the boss, for sure.

What is perfect weather for sap to run?

Perfect weather is around -2° to -3° C overnight and then a nice sunny day getting up to 5° or 6° C.

Why does temperature affect the sap coming out of the tree?

The tree actually recharges when it cools down and freezes up. That’s when it draws fresh sap from the root system. When it thaws out, sap continues its way up to the branches to feed the buds so the new leaves can come out.

You’re basically catching that sap as it goes up and down the tree. That’s why you can only do it in the springtime?

Yes. We’re just intercepting a little bit of that flow and taking it to make syrup.

How many of these taps would you have? You have these spread out over several bushes. How many taps do you have in a year?

There’s probably somewhere between 7,000 and 8,000 taps in our operation. It’s a lot of work. You’ve got to cut all the wood to clean everything up, put in the spiles and lines, make sure everything works and then you’re ready to go.

You are also open for tours (When it isn’t a pandemic).

Yes, we have a lot of people visit us here at the farm, including a lot of school kids. Each year over 6,000 people visit on the weekends over a six weeks period. During the week a lot of school kids come out.

Thank you Lawrence for touring us around the sugar bush. His brother, Colin is now going to show us how they boil the sap to make syrup.

We collect sap from eight woodlots. It is all brought to this location and stored in tanks until we are ready to process it. The first step is to pump the syrup through this reverse osmosis machine to take out a lot of the water before we cook it. It concentrates the sap and saves a lot of time and a lot of energy.

Can we take a look at the reverse osmosis machine?

This machine is a two-post machine. There is a high-pressure pump back here that creates a lot of pressure. Right now we’re at about 350 PSI. It is pumping the sap through a membrane. The membrane is 20 cm (8 inches) by 102 cm (40 inches) and there are two of them. This machine will process about 2.25 kL (500 gallons) an hour of maple sap.

How do the membranes work? How does it know to toss water out and keep the sap in?

The membranes are specially designed for the maple syrup industry. It can also be used for other things like purification of water. There is a really fine filter. We pump the sap through it. The sugar that we want to keep to make maple syrup will not go through that filter. The water goes through the filter and is piped out. You can see it is clear pure water; you can drink it.

Membrane 1 is taking out about 32 litres(7 gallons) per minute of water and membrane 2 takes about 23 litres (5 gallons) per minute of water. We’re taking out 55 litres (12 gallons) per minute of water and we’re keeping 18 litres (4 gallons) per minute of concentrated maple sap. We’re basically keeping 20% of the original sap, so you can see why this saves a lot of time and a lot of energy.

Where does the sap go from here?

After it goes through the reverse osmosis, it gets pumped up top to a tank outside and then the sap runs in a ballast tank. We use the ballast tank so the same amount of pressure is kept on the float at all times so that flue pans in the evaporator stay level.

This is the evaporator. How does it work?

It evaporates off more water. The sap is coming into the evaporator onto the flue pan. Each pan has a float to keep it at a constant level. As the water is being cooked off or evaporated off, there’s always fresh syrup coming in so there is continuous flow when we’re cooking. The raw sap comes into the evaporator on one side and as it moves through the evaporator and water is removed, it gets thicker and more like syrup. It keeps running through the evaporator and the farther it moves through, the thicker it becomes. There are three channels in the evaporator. It starts at the back of the evaporator then it comes to the front, then it goes to the back, then comes to front again, and then it comes off on the other side into syrup pans. Syrup pans are large flat-bottomed pans with channels and a float to control the level of syrup in the pan. The syrup comes into the pan on one end and follows the channels through to the other end of the syrup pan.

How are you heating the evaporator?

Here at Fort Rose, we’re still burning wood for most of our heat. We cut all the wood.

How many liters of syrup are you hoping to make in the year?

Generally we make about 8,500 to 9,000 litres of maple syrup each year.

You have a second evaporator. Why is that?

We’re doing most of the cooking with wood, but we finish cooking syrup using furnace oil in the second evaporator. We use furnace oil because it’s a nice constant heat. When you add fresh wood, you get a lot of heat right off the bat. When maple syrup is getting close to being done, it gets really foamy. We can have issues with it boiling over the pan. So, basically it comes across onto another float into the finishing pan. This is a two and a half by six foot oil-fire finisher. The syrup just comes into the pan from the evaporator and it goes through all the channels. If you look in the finisher, when the syrup just comes into the pan, there is not a lot of foam and when you come down to the other end there is quite a bit of foam.

If it did get too foamy, what would happen?

It would boil over the side.

Just like a pot of potatoes in the house, and it’ll make a mess. How does the equipment prevent the syrup from boiling over?

When you’re cooking syrup, the boiling temperature of maple syrup is 104° Celsius (219° Fahrenheit). Water boils at 100° C (212° F) syrup boils at 104° C (219° F). There is a controller attached to a thermometer in the pan, and when syrup gets hot enough, it is automatically drawn off. We watch it constantly as it also depends on the day. If you’ve got a lower air pressure day, the boiling temperature of water is lower. The other day I was cooking and taking off syrup at 103° C (217° F).

So, if you had put that up to 104°C (219°F) it would have boiled over then?

It would not boil over, but it would make a thicker syrup. The problem with making your syrup too thick is that it will crystallize in the jug.

And nobody likes that on their pancakes!

Right. The crystals are just sugar, but we are careful not to make it too thick.

How do you get it into the barrels or into the jugs?

After it comes off, we put it through a filter press. The filter press is just a bunch of plates. The first plate is where the sugar sand is removed. Sugar sand comes out of the sap and it basically looks like really fine white sand. After the syrup comes through the filter press, it comes out on the other side nice and clean.

I have noticed that there are different colours of maple syrup. Why is that?

Maple syrup that is harvested at the beginning of the season when the weather is cooler makes a lighter grade of syrup. As the season goes on, there are different types of sugar in the maple sap and that balance will change with the weather and with air pressure. This gives you different colours and flavours. Today we’re making light and eventually, maybe next week we’ll make a medium and then we’ll make an amber and then a dark right at the end of the season.

Do you bottle syrup yourself and then you sell most of it here?

We sell probably 60% of our sales right here during the season. We have signs up on the main road and people come back each year or new people that drive by come into the yard. We do sell in stores. We wholesale in containers to a few other places. The darker syrup has a strong flavour which bakeries and sauce makers like so we put it in barrels and then wholesale it.