Update: April 30 - Final Update (1+ month after initial tapping)
By the middle of the month, temperatures started to remain consistently above freezing. The two smaller sugar maples slowed to a tiny trickle, then went dry entirely - but not before one of them produced a very golden-looking bucket of sap. I wasn't sure what that meant, so I stored that batch separately.
Spring at UMEX
The big Silver Maple soon followed by going dry. The larger front Sugar Maple, however, continued to produce a fairly constant liter or so of sap per day. The smell of the sap seemed a touch more musty, but on-the-spot tasting of the sap didn't reveal it to be off in any way I could detect. Having heard stories of so-called "buddy sap", I was wary, and kept the sap from this tree separate as well. Suprisingly, this tree kept producing sap like this for almost a week, even though the temperatures had become downright summery.
Dry and Fly
With the taps removed from the trees and the buckets put away, it was time to turn attention to the last batches of syrup production. Seeing as the amounts were now relatively small, there was no longer a rush to process as quickly as possible. The final batch of "golden" sap from one of the small Sugar Maples ended up producing a very dark - almost black, to my eyes, syrup. I feared that this was the dreaded "buddy sap" syrup, but no - it was actually very good. Compared to the very first batch of Silver Maple sap, the color difference was striking.
That first batch of Silver Maple sap had also accumulated a large amount of sugar crystals in the bottom of the bottle. There had been crystals nearly from the time of bottling (indicating that I had cooked it to too high of a temperature), but the long period in the fridge had encouraged many more crystals to precipitate out. Fortunately, none of my subsequent batches of syrup exhibited any crystal precipitation.
When syrup gets too hot
The other late batch of sap - the sap that was collected for nearly a week after all of the other trees had gone dry - was a different story. As I started to boil it down, it began to exhibit a vague sour-like smell. Periodic tasting of this revealed that it was still sweet, but different in a subtle way.
The sour-ish quality intensified as the sap became more reduced. Eventually about 400ml of syrup was produced out of this batch, and it tasted - weird. Still very sweet, but with a sour component that was edible but not entirely pleasant. Was this an example of the syrup that came from so-called "buddy sap"? If so, I was glad that I had kept the sap batches separate from one another.
Curiously enough, this off-syrup was the exact same color as a very nice-tasting batch of syrup from a week before.
Class of 2015
The strange final bit of syrup aside, I think it is safe to say that UMEX 2015 was a resounding success. What I had thought was a relatively ambitious goal of 4 litres of maple syrup turned out to have been a gross underestimate. The backyard trees produced about 320 to 350 litres of sap, which in turn yielded about 10 (ten!) litres of maple syrup. I think that is an excellent result from four backyard maple trees.
An impressive variety of colors
So, will we do this again next year? To be honest, I don't know. It is definitely a lot of work, and a big time commitment. The local / sustainable angle is kind of neat, and I also like the ability to obtain unique types and blends of syrups. If we do it next year, maybe a tube-system is a good idea. We shall see...
And finally, to commemorate the whole urban maple syrup experiment experience, here's a video montage, set to the music of Pete Seeger's "Maple Syrup Time":
UMEX 2015 Video Montage - Click on video above to start
