Here is our final Datacer post, our next update will detail the results of our 2022 season, which is looking a lot like 2021.

One interesting drawback of high vacuum is the effect it has on the freezing point of water. Sap can be treated as water since it’s 98-99% water. We all know that water freezes at 32°F under normal conditions, but most people don’t know that under vacuum the freezing point can easily approach 35-40°F! In years past we noticed that even though the outside temperature would hover a few degrees above freezing, our releasers would fill with ice and sap would stop flowing. This is caused by the higher freezing point and amplified by leaks in the system. As air enters tubing through various leaks, it expands, releasing energy and dropping the localized temperature several degrees. These two effects work together, stopping sap flow prematurely.

We always try to minimize leaks, but it is nearly impossible to find every micro leak over 110 miles of tubing. This year we’re fighting freeze ups another way, by adjusting our vacuum level based on the weather. As the air temperature approaches freezing, our pumps spin slower and our input line is chocked off by a modulating valve. We configure several temperature/vacuum set points to optimize sap flow but prevent freezing. Two additional benefits are that our pumps use less power when it’s below freezing, saving us hundreds of dollars in electricity each year, and that the modulating valve can be closed if the releaser floods, preventing our vacuum pump from sucking sap. We ran this system on three of our four properties this year and will be adding it to our fourth over the summer.

First, another season update. This season is looking a lot like 2021, a mostly frozen January/February followed by a flood of sap in early March, then warm weather with no freezes. We’ve passed our 2021 production numbers by 5-10% to put us at 85% of a normal crop. Based on other reports in the area we feel fortunate to have that much. Our pumps are still hoping it freezes tonight and that the taps are not dried out just yet.

Another Datacer update. One great feature is the ability to turn the vacuum pump on/off remotely. In February we had an unexpected issue where ice formed in a releaser, preventing the submersible pumps from running. We noticed this while at another property. Instead of racing home to turn the vacuum pump off before it sucked sap, we were able to press a few buttons and turn it off from 20 miles away. Anyone who has ever cleaned a flooded rotary claw pump knows how valuable this is! The pumphouse controller has several other features, including tank level sensors, pressure sensors, sap drain control, and indoor/outdoor temperature monitors.

Quick season update – We’ve made over 50% of the syrup we made last year, and if you count all of the sugar in the evaporator/chiller/tanks we’re probably approachingg 50% of a normal crop (last year we only hit around 80% due to poor weather). We should get a few decent runs this week, a nice freeze over the weekend, then some big runs next week!

We’ve been using our Datacer tank sensors to calculate gallons of sap per hour. Based on the attached chart, our 4,000 gallon tank filled up in 4 hours, so our 7,000 taps at this location ran 1,000 gallons/hour! All four tanks filled up that day, we were very close to overflowing but managed to get our truck there in time. We’ve always had cameras on our tanks but this allows us to quickly calculate when they would overflow, sometimes allowing us to sleep easier at night!