Mr. Lockman is a man with many skills knows how to push the Tappecue to the limits! Here is his latest project.
Tappecue Try SAP-pecue
We all know how awesome maple sugar and maple syrup are as ingredients for our BBQ rubs and sauces, but have you thought about how it’s made? It’s pretty simple, really, but knowing when it’s done can be tricky. There are a number of tests for “done-ness,” including measuring the viscosity, density and boiling temperature.
Maple sugar and maple syrup come from the sap of the maple tree. Maple trees are special in that in certain parts of the year, their sap is basically slightly sweet water. At other times of the year, it’s more like tree sap with a decidedly un-gourmet flavor. Birch trees have sweet sap, too, but birch sap is much less sweet than maple sap. The sweet sap happens in the spring, when the trees are reviving after a cold winter, and in the fall, when the trees are preparing for the next cold winter. Flow in the spring is tied to the weather: cold nights freeze the tissues of the tree, causing vacuum and sucking sap up into the body of the tree. During the day, the tissues expand as they warm, causing positive pressure and driving the sap down to the ground. If you drill a hole in the tree, you can catch the sap on the way down. In our case, we insert a small tube called a spile into the hole we drill, and catch the sap in a bucket. Once we have enough sap, it’s time to remove the water and get to the golden sweetness.
Most people remove the water by boiling the sap, which is the easy part. Really, how hard is it to boil water? The trick is that you need to boil a LOT of water (sap) to get a little bit of sugar or syrup. Most trees’ sap needs to be reduced to 1/40th of its original volume in order to get to syrup. In other words, it takes 40 gallons of sap to make 1 gallon of syrup. That’s a lot of heat, and a lot of patience. Most producers boil in a large pan and continually add fresh sap as the water evaporates, gradually increasing the sugar concentration. For many years, we used a large, flat pan over a big fire. The drawback here is that when it’s done, you need to somehow stop the boiling and remove all of the syrup from the very unwieldy pan. We switched to a different pan that is essentially a very long skinny pan that is folded back on itself. You add sap at one end and the syrup collects at the other end as the liquid boils. Chemically, there is a density gradient along the length of the pan caused by the continual removal of water as steam from the pan. The more you boil and continue to add fresh sap, the steeper the density gradient becomes over time. Also, the pan has a valve at the syrup end so you can remove the syrup without stopping the boil. It’s way better, and there a wide array of variations of this kind of pan.
Now, as the sap boils, its sugar concentration increases and its boiling point goes up. One of the tests for “done-ness” is that the reduced liquid boils at 4°C above the boiling point of water, and measuring the boiling point is where Tappecue comes in. We rely on the density of the liquid as our accurate measure, however, as the boiling point changes with weather conditions. The temperature, however, is a very good indicator of how close we are to having syrup.
I started with a Tappecue long probe, but discovered that the high humidity environment required a little modification. I put some shrink tube over the crimp and extended it out along the wire, and then added some RTV silicone to seal up any gaps.
The “factory” probe on the bottom, and the sheathed probe on the top. It is important that the sheath extend beyond the strain reliever built into the probe.
A little dab of RTV seals the end where the tube didn’t shrink quite enough. Make sure it gets into all of the gaps.
Due to the shape of the pan, I use two clips: one as a standoff, and one to hold the probe in place. The wire (with its shrink tube and RTV sheath) is bent over out of the steam and connects to Tappecue.
Prior to Tappecue, I couldn’t leave the cooker unattended for fear of losing my boil (because I didn’t put in wood), or for fear of overcooking the syrup and burning the pan. Trust me: a sugar fire is very bad, and if you’re not paying attention, it can happen very quickly. With Tappecue, I can sit in my home office and monitor the boil from afar. Of course, I have my Tappecue Extension for Creative Cloud installed, so when I’m Photoshopping or making web sites with Dreamweaver, I can always know the temperature of my boil.
When it gets to 219°F, it’s time to pay attention and start measuring the density of the syrup. We use a specially calibrated hydrometer so we know we have it just right. Once it’s ready, we open the valve and draw off some syrup, filter it, and put it into bottles.
If you happen to be in Maine on March 25th, come visit us for the Maine Maple Sunday open house. Here’s our Facebook page where you can learn more.