We’ve been running the reverse osmosis system at about 95 PSI and concentrating the sap from around 2 percent to 7-8 percent. That’s a lot of water being pulled out (and the water tests at 0 … so we’re not wasting a statistically significant amount of sugar in the filtering process).
Tag: maple sap
Reverse Osmosis Maple Sap Stats
We collected nine gallons of sap with SG of 1.009 = 2.3 Brix
We ran all of the sap through the reverse osmosis system at 60psi and had sap with SG 1.011 = 2.8 Brix
We ran the concentrated sap through the reverse osmosis system a second time, this time at 80psi and had sap with SG 1.022 = 5.6 Brix.
The “pure water” output SG was about 1.003 — we re-ran this through the RO as well.
At the end of the day, we have about 4 gallons of sap at 5.6% sugar, another gallon from the “pure water” run that’s a lower SG, and four gallons of water that’s removed.
Notes for the future:
- We want to see what a single pass at higher pressure does — is it multiple passes that farther concentrated the sap or the higher pressure?
- We took SG readings and converted to brix using an online converter. Next time, we should just take the readings in Brix 🙂
- We might need a different refractometer to get accurate readings near 1 … not sure how accurate our tool is at the low end of the range.
Maple Syrup Reverse Osmosis Build
We’ve got all the bits and pieces to assemble our maple reverse osmosis system — four 150 gallon per day filters, a pre-filter, pump, pressure gauge, and a valve to control how much pressure we allow to build up in the system. Plus some tubing and connectors, of course!
2021 Maple Syrup Season – Final batch
We got fifteen full pints and a partial pint (plus a cup that Scott took out to enjoy early) of late-season maple syrup in our third batch. That gives us five and a half gallons of syrup this year — and we’ve got about eight more trees that we can tap next year.
Maple Syrup Batch 2
18 pints in our second batch!
Maple Syrup Batch 1
We canned the first batch of maple syrup today — 10 pints
Maple Season Begins
Sap is boiling! We tapped about thirteen trees so far, and collected about 20 gallons of sap today.
DIY Reverse Osmosis Filter for Maple Sap
Notes from the reverse osmosis system build we are planning:
Ideally, we run RO inside — lose 3% efficiency on RO for every degree drop, and systems are rated at 77 F. Is this bad for sap storage, though?
Multiple RO membranes connected in series (“dirty” out goes to next one’s “in”, “clean” out goes to fresh water collection). 3x or 4x membrane — more concentrated as fluid runs through each of the membranes. Diminishing returns, 3-4 max units.
Process:
Sap goes into rain barrel — need valve out from rain barrel. Sensor in sap holding tank and smart outlet for pump — turn off pump when tank is near empty.
Pumped from rain barrel holding tank to filter. Output from filter to input on first RO.
“Fresh water” output from each RO goes to fresh water holding tank (rain barrel). “Dirty stuff” output from each RO goes to input on next RO for farther concentration.
“Dirty stuff” output from final RO, the concentrated sap, goes into Digiboil (65L, ~17 gallons of liquid)
Little pump we use for brewing draws from Digiboil to fill boil trays on the burners.
RO system:
Pump — need to compare this one and this $40 one.
Water filter housing Either with 1/4″ inputs or 3/8″ inputs — prefer 3/8″
Water filter 10″ long x 2.5″ across filters — these look like they’d fit
RO membrane & housing combo but we can get replacement things from Ali for about $10
Connections:
Something from rain barrel to 3/8″ input on pump — GHT female and 3/8″ male
Something from 3/8″ output on pump to 3/8″ input on filter
Something from 3/8″ output on filter to 1/4″ input on RO
3/8″ tubing from rain barrel to pump, from pump to filter, and from filter to RO
1/4″ tubing to run between RO filters
1/4″ tubing from each RO to fresh water holding tank
1/4″ tubing from last RO to Digiboil
2020 Maple Syrup
Our taps are drying up — some of them were drilled on 03 February. The weather is getting warm; a few trees have leafed out. Our maple season is coming to a close. We’ve got more than five gallons of maple syrup canned:
18 Feb 2020 — 1st batch — ~3/4 gallon, a little scorched and used for cooking instead of canned
25 Feb 2020 — 2nd batch — 6 pints
10 Mar 2020 — 3rd batch — 24 pints
26 Mar 2020 — 4th batch — 10 pints
04 April 2020 — 5th batch — 2.75 pints
Maple Sap Season Coming To A Close
We’re getting to the end of maple sap season – collecting a last batch of sap and boiling this week. We should get another gallon or so of syrup, but the red maples are well into leafing out. I’ve heard a lot of descriptions of the sap flavour after bud-break … to me, it is tannin heavy. That would put us around four gallons of syrup for the year — and re-enforce my belief that the algorithm determined tapping date is when we should tap – even if that’s the second week of January!