John Allin
14x18 Hemlock Timber Frame Sugar House 2009
Leader 2x6 w/Patriot Raised Flue Pan 2009
Leader Steam Hood 2014 - Clear Filter Press 2015
Leader Revolution Pan and SS Pre-Heater 2016
CDL Hobby RO & Air Tech L25 Hi Vac Pump 2019
06' Gator HPX to collect wood & sap
14' Ski-Doo Tundra for winter work in the woods
Great Family 3 grown kids+spouses and 7 grand kids who like the woods
7th Gen Born in Canada - Raised in Chardon Ohio - Maple Capital of the World..<grin>.
John Allin
14x18 Hemlock Timber Frame Sugar House 2009
Leader 2x6 w/Patriot Raised Flue Pan 2009
Leader Steam Hood 2014 - Clear Filter Press 2015
Leader Revolution Pan and SS Pre-Heater 2016
CDL Hobby RO & Air Tech L25 Hi Vac Pump 2019
06' Gator HPX to collect wood & sap
14' Ski-Doo Tundra for winter work in the woods
Great Family 3 grown kids+spouses and 7 grand kids who like the woods
7th Gen Born in Canada - Raised in Chardon Ohio - Maple Capital of the World..<grin>.
None of this is terribly surprising. Length of time, temperature, number and type of microbes, and aeration will all influence (hasten) many of the biological factors and chemical reactions resulting in more color/flavor development, and in some cases, reduce the level of precursors of off-flavor. The difference is that (some) people are now looking to go towards darker/stronger syrup, whereas most of the efforts maple producers have taken over the past 100 yrs has been aimed at going the other way (towards making lighter syrup).
Dr. Tim Perkins
UVM Proctor Maple Research Ctr
http://www.uvm.edu/~pmrc
https://mapleresearch.org
Timothy.Perkins@uvm.edu
Air injection into pans produces light syrup. Air injection into sap produces darker syrup. A little paradoxical isn't it. ;^)
You might think so, but no. The reaction with air injection IN THE PANS is not a bleaching effect, but rather is a prevention or reduction of of color/flavor formation effect (I won't get into the chemical reasons, but it is largely due to a reduction in temperature resulting in a reduction in caramelization of invert).So does that mean that at the end of the season one could in theory introduce air for the purpose of reducing off flavor and inadvertently darken the finished product but introduce air in the evaporator while cooking the sap and lighten it back with a more delicate flavor?
The air injection INTO SAP effect is different. In this case you are:
1. volatilizing (reducing) off-flavor precursor compounds in the sap that result in poor flavor
2. enhancing formation of invert (higher temperature, more oxygen, longer time period) which increases color/flavor formation.
3. altering the biome of microbes in the sap.
4. increase the rate of biological and chemical reactions in sap leading to color/flavor development.
All of these factors INCREASE color/flavor development (and can, perhaps, decrease some off-flavor precursors), thus darker syrup is formed upon boiling. Essentially you are controlling the fermentation level in the sap. The danger is the possibility of turning your sap/syrup ropey.
Now if you used air injection in your pans to process aerated sap, you'd make lighter syrup, but it wouldn't be quite as light as if you had not aerated the sap. It would certainly be possible to vary the amount of air injection in the pans to be able to produce somewhat lighter or darker syrup according to your wishes (dial-a-grade syrup).
Dr. Tim Perkins
UVM Proctor Maple Research Ctr
http://www.uvm.edu/~pmrc
https://mapleresearch.org
Timothy.Perkins@uvm.edu
Sap aeration and it’s effects on flavor and grade are very intriguing.
Been hearing a bit about it but if anyone has recommended ways to best set it up (hopefully without breaking the bank) I’d be interested. Or articles or other threads...
Dr. Tim could you elaborate a bit on the danger of going ropey due to aeration? The factors at play and what to watch our for?
Thanks so much!
Mike
The Bunker Farm
Dummerston VT
There simply is not sufficient research on the subject to give good answers. Aeration of sap MIGHT help in some ways by reducing microbial growth (or at least the bad microbes) and promote the development of stronger flavors (darker syrup) as well as help reduce volatile precursors of some off-flavors (metabolism and/or buddy perhaps), but it is still far from being a tried and true method. Too many variables and uncertainties to give recommendations at this time. As far as ropey sap goes...microbes + time + temperature result in spoilage. If the improper microbes are around...it'll eventually go ropey. Aeration might delay it a bit (maybe).
Dr. Tim Perkins
UVM Proctor Maple Research Ctr
http://www.uvm.edu/~pmrc
https://mapleresearch.org
Timothy.Perkins@uvm.edu
We have been experimenting with Sap aeration this year. On the positive side: The passive evaporation loss (1-2%) is nice and the ability to keep the sap from freezing at night was very helpful. On the negative side once temps warmed up we got lots of scum/bubbles as the bacteria went into overdrive, especially in the RO concentrated sap. Side by side taste tests of both cold/warm aerated syrup to the non-aerated control syrups we had trouble distinguishing them apart. Since we boil outside all our syrup tends to be darker/more robust, so we couldn't really tell a difference but we are also not experts.
I do think there are some potential benefits to aeration from the evaporation and the freeze prevention, but is is also another 110v device running overnight..
I would love to see a more detailed control study of sap aeration benefits besides just late season sap salvaging.
J
This is very interesting! From reading this article it reminds me of a large producer in Canada whom does the opposite! By filling their sap storage tanks from the bottom of the tank, they create an environment where they create less aeration/Via bacterial growth… So if anybody’s doing this aeration of sap,(and I understand why you would want to do it!) has anybody tried using a protein skimmer in their sap tank… Similar to what you would use in a saltwater fish tank to Skim off the bacteria, Or is there a different method(perhaps charcoal filter?) Or does it not need to be done at all?
Interesting idea.
Just to save people from googling it, as I remember a protein skimmer essentially is a column full of water from the tank. A pump generates bubbles in the water. The bubbles create a foam which consists largely of proteins (wastes). This foam builds up and spills over into a container which is then cleaned out. The purified water returns to the tank.
Sugaring since 2000.
2022 - 113 taps on tubing and gravity. Homemade evaporator and RO.
2023 - 120 taps on 5/16 and gravity added a float to the pan an built a new 5x400gpd RO