In maple sugaring, the equipment that claims the cruelest name is the “extractor,” a device that sounds like it preys on maple trees. What it really does is separate out the sap flowing down toward a vacuum system and puts it into a storage tank without interrupting the flow of vacuum to the tree.

[The Not-Very-Quaint Extractor]

Buckets and horses it ain’t. It’s a clever device, and useful in that you can calculate your sap flow by timing how frequently it extracts with its electric pump.

Tonight, visiting our rented sugar bush to see if I needed to turn off the vacuum system due to rapidly freezing conditions, I set down to first calculate the extracting times with a stopwatch.

I didn’t set this bush up. A man named Chaz did, and I came along to rent it from his family after he passed away a few years ago.

[The Sugarhouse at Chaz’s Bush]

Our extractor throws about four gallons of sap at a time, so when we see it working every three minutes, we know that we’re running about 80 gallons per hour out of the forest, or about enough to make two gallons of maple syrup. The pump clicks on after 2 minutes, 56 seconds.

Just one test is often misleading, so I reset the watch to restart. Killing time, I start going through the trove of Chaz’s notes from years past. Manuals, sugar line layouts, some day-to-day notes. The notes are precious. They show how this bush’s trees interact with weather and temperature, seasons and how Chaz’s equipment – much of which I use – interacts with the sap to create light and dark maple syrup. He’s written down settings, mistakes, clever work-arounds and even occasionally how he felt.

3 minutes, 9 seconds later, I hear the extractor click the pump on. I could use another data point.

My sugaring buddy and I have been arguing back and forth about whether the season is over, or if we’re just in a dry patch for sap. I start rifling through Chaz’s notes to see when he stopped. He ended his seasons on April 14, 2, 21 and once on March 23, although the notes then indicate “burned the finish pan,” so I won’t count that one.

I hear the extractor pump turn on, so I push the lap button on the stopwatch. 3 minutes, 37 seconds that time, slowing a little.

Some of his notes are prosaic things only another maple syrup maker would find interesting, like the sugar content of his sap (high then as it is now, at about 2.5 percent), and others barely describe the drama I’m sure was involved (“March 20: Leak in flue pan”) which was probably very much like the day, almost exactly a year later, “9.5 inches of sap. Burned front pan.”

The extractor clicks on, and I push the lap button on the stopwatch. 4 minutes, 1 second this time.

In 2003, when Chaz was sick, there are blank spaces. You can see him backfilling dates with temperatures, and once writing on March 24 “Was in hospital since the 21rst.”

I didn’t see a lot of syrup quantity recorded day-to-day in that calendar. He’d put out a gallon of maple syrup one day, a few days later three gallons of maple syrup. The inconsistent boiling took a toll on the grade, with the maple syrup descending to Grade C on March 25. Chaz did a “push” the next day, putting plain water through the back of the pan to push through the remaining maple syrup before he would dump the pans, clean them and start over.

I notice the extractor has been going for a few seconds, so I reset the stopwatch. It was 4 minutes, 30 seconds. A whole lot slower now.

It took three days of boiling after that to get the sugar content back up in the pans, and the first batch of maple syrup must have been frustrating because it was Grade C again. It would have come back up after that, but the weather let Chaz down, turning cold enough to deny him sap for nine straight days, and allowing the sap he did have in his pans to sour. He cleaned again the day before the big runs on April 10 and 11, making a range of Dark Amber, B and then C again.

Those days and the three next brought Chaz 36 gallons of maple syrup, by far the most he’d ever made in such a period. The next day: “Very warm. I quit.” It was 76 degrees outside, a clear day and a night of a full moon.

5 minutes and 20 seconds had gone by. The extractor clicked on. I pocketed the timer and grabbed Chaz’s notes. There was truly a trove of useful information (that, for instance, the automatic draw off device I was contemplating using actually doesn’t work).

[Before Chaz, the Old Sugarhouse Up Atop the Hill]

I peer into the extractor’s input pane and can see that the sap lines must be freezing up. There’s little sap coming in, and the pressure gauge is steadily climbing as ice blocks major parts of the lines. I throw the switch on the wall with a satisfying “clunk,” turning off the vacuum. With some cold this evening, we’ll get some more flow tomorrow, and maybe extend our season one or two more days. It’s April 8, a full moon lights the outside; a fair time to think about stopping for those who would, but I going to decline. I still hold out hope for a last charge of sap in the face of the oncoming spring. We still have much to make up.

Another reader question:

I am looking for some help in my own attempt at maple sugaring. This is the first time we have ever attempted this, and the syrup we produced has a very off flavor. Almost like rotten fruit? Any tips? -Tara

There are a few things that can cause these off flavors in maple syrup. I’ll list them out, and perhaps one or two will jump out at you.

Perhaps the most common cause of such an off flavor is boiling sap that has been kept too long before boiling, or stored in a warm and/or concentrated form. I made some very nice rotten fruit maple syrup a year ago on my last day, concentrating some sap partially and then letting it sit up in the sugarhouse attic for three days getting nice and toasty in the April sun before doing my last boil. Specifically, it tasted like rotten oranges. I sacrificed that batch to the farmyard as an offering for a good maple syrup season in 2009.

Remember that while bacteria are breeding in your sap, they’re eating your sugar and excreting compounds that are generally not good for the maple syrup flavor. The specific type of critters you have growing can vary, and their off-flavors will vary along with them. We’re contemplating installing an ultra-violet filtering system on our sap and concentrate tanks next year, so as to be able to more comfortably store sap and boil more strategically. For the backyard sugarer, that wouldn’t make any sense at all. You might, though, contemplate whether or not you really want to hold over sap from Monday’s buckets to the Saturday during which you have time to boil.

Sometimes, rather unpredictably, maple trees will go through a “metabolism” stage, where it will generate an off-flavored sap. When that happens, it’s usually not a local phenomenon, and can be seen across an area. I haven’t had this happen to me, but a few years back a lot of New England maple syrup producers found this happening, and they reported that the maple syrup had a distinct “sweaty sock” taste. Makes your mouth water just thinking about it. Proctor Maple Research Center is in the midst of some good research on this phenomenon. They’re trying to pin down both the cause and any actions a sugarmaker might take in order to prevent or correct the problem.

I have a few local folks who just started maple syruping coming by the sugar shack this year, showing off some samples of Fancy maple syrup. That’s impressive, given that it’s tough to make fancy off a stovetop, but it’s also fairly common for the light and subtle taste of fancy maple syrup to reveal the presence of pan cleaner residue, or even of odors baked into the sap while boiling, such as cigarette smoke or just plain not-very-well-vented firebox smoke. With the sometimes fruity taste of fancy maple syrup, those off-flavors can combine to give a rotten fruit sort of flavor.

A reader question:

I'd like some expert advice. I have a tiny operation with a camp stove on my deck. I've decided to pre-heat sap on my kitchen stove to speed up processing time. I'm using the pressure cooker, to get the sap up to boil, then releasing the steam outside and adding it to the already boiling sap. Any thought about that? Any problems other than watching the pressure cooker carefully?

-Kristin

Kristin, your system is actually very clever. Boiling at high pressures saves fuel and causes the sap to experience lower heats, preventing early caramelization of the maple syrup and other processes that can produce off-flavors.

The principle works like this: the higher the air pressure, the lower the boiling point of water (or sap). That means you need less heat to get the fluid boiling and thereby shedding water. It also means that it boils cooler, which prevents the sap from overcooking, causing darker grades of maple syrup and burnt flavors.

I’ve been toying with the idea of experimenting with something called mechanical compression, which would allow my boil to take place at very, very low temperatures. My wife thinks I’m going to blow myself up with this, though, and I’m not exactly sure she’s wrong, so I’ve been taking it slow.

Suffice it to say that your system of pre-heating the sap with a pressure cooker should work fine, if you keep a good eye on it. You may find that in transferring the boiling sap in the pressure cooker to the main sugar pan, the boil is lost, though, because the original boil was actually at a lower temperature than is possible in the normal atmosphere.

The one thing I’d caution you on is letting it boil too long in the pressure cooker, as you’d just be exposing the sap to heat without letting the steam out. If the sugar pan is a bit ahead of the pressure cooker, you’d have the best of both worlds.

Good luck with this. Let us know if you discover any neat learnings. And do look out for that steam. It’ll really do a number on you if you expose yourself to it, or allow it to build up and cause an explosion.

We packed some of our Grade A Dark Amber maple syrup into our square bottles a few nights ago. We pack it strong. They were left overnight on the cold concrete floor, as temperatures dipped pretty low. The maple syrup at that temperature can keep only so much sugar in solution, so some of it started to crystallize on the bottom. It’s a beautiful thing, a dusting of shiny crystals on the bottom of a maple syrup bottle. You know it’ll be thick and strong.

One element I’ve been thinking about: if we’re boiling down extra strong, the sugar content of that syrup is obviously higher than normal. A New Hampshire syrup might be below 68 percent sugar. A Vermont syrup should be just above 68 percent. We’ll pack it at about 70 or so. But when the sugar comes out of solution like this, folks say it’s just back to normal syrup. Except, I think it’s not. You see, those sugar crystals don’t taste like maple syrup. They’re just pure sugar. Which means that all the extra maple flavor associated with that volume of syrup remains in the bottle. Here is a picture of the same bottle in the evening...

[This is, quite literally, stored energy]

I need to test this more carefully, but I believe that a bottle of overstrength maple syrup that has been brought back to normal strength through sugar crystals forming will have a higher rate of maple syrup flavor than a bottle that was just brought to normal density in the first place. We could probably best test this with some Grade A Fancy, where the normal strength maple syrup lacks the strong flavor of the darker grades of maple syrup. Sounds like a great excuse to do another tasting.