Last Updated on June 20, 2024 by Michelle
Want to know how to build your own Reverse Osmosis for making maple syrup?
Want to save money making maple syrup?
Every detail you need to know is all broken down for you right here.
I’m elated that you found this page. If you’re a backyard sugarmaker looking to save money, this article will make your day, just like it did for Jeff Whitmore and Eric Shufelt:
Hi, I’m Michelle. A backyard sugarmaker in New England, and author of Sweet Maple.
Please consider helping me support sugarmaking education worldwide with every purchase of SoulyRested Swag. You’ll find the latest designs right here (like the one I’m wearing here) .
But first, let me applaud you. Seriously. I have huge respect for DIYers like you who know what they want and can seriously build it.
I’m not like you. I love making syrup, and baking with syrup, making maple cream (my favorite form of maple), and writing about maple syrup, but I do not know how to build something like this awesome Reverse Osmosis set up that we have.
Nope, that’s all my husband’s ingenuity. And I have huge respect for Bill and for YOU, since you’re here.
Me? I wouldn’t know how to even cut the plywood the size I wanted it. True story.
Can you save money making maple syrup?
The best way to save money making maple syrup is to cut down your boil time, and save in your fuel costs. The best way to do this and save money making maple syrup? By building a Reverse Osmosis system for maple syrup. And that, my friend, is exactly what this article is all about.
Yep, you’ve stumbled across the Holy Grail for saving money while making maple syrup…
What is Reverse Osmosis for maple syrup?
A Reverse Osmosis system (lovingly referred to as “RO” in the sugar making world) is the same idea as that fancy filter many folks have under their sink, filtering their water.
But a sugar maker reverses the system, and instead of filtering out impurities to produce pure water, we filter out the water and keep the “impurities,” aka SUGAR. By removing a nice percentage of the water in the tree sap, we increase the brix of the sap and reduce our boiling time.
Read more about measuring brix in your sap and syrup here.
Save money and build a DIY Reverse Osmosis system.
So I asked Bill to walk me through exactly what he did to make this sweet contraption. Since it saves us hundreds of dollars every year in fuel costs as we boil our sap, I totally want to tell y’all exactly how to build your own.
I also list, below, every single item Bill bought to build our system.
If you are still learning how to collect, boil, and bottle maple syrup, head over here to this article about making syrup, step-by-step or, better yet, pick up a copy of Sweet Maple. It’s being hailed at the “Book of Knowledge of all Things Maple.”
But maybe you stumbled here wondering what an “ro system” is, I’ll explain…
What is a homemade reverse osmosis (RO) system?
A DIY Reverse Osmosis is exactly like a water filtering system. You know the ones that that filter out the impurities and leave you with wonderfully pure drinking water? (In fact, you’ll see below that’s exactly what we’re using–filters from a water purifying system.)
Except sugarmakers use the idea in reverse. We filter out the “impurities” (aka the sugars in the sap) and keep them. That’s what we boil down to make syrup. But after the sap has run through the ro system, we can spend a lot less time, energy, and fuel to boil it. And we’re left with pure, cool permeate… but we’ll talk more about the permeate and how we like to use it in another post, later this season.
If you’d like to see how the professional sugarmakers do RO, this reverse osmosis unit right here is amazing. (And here’s a facebook live video showing how it works.) Maybe some day we will upgrade to that fancy-shamancy gorgeous thing. But for now, our little homemade one gets the job done.
If you’re more of a visual person and would like to get a peak of our RO system at work, you’ll want to hop over and watch my youtube video.
Does Reverse Osmosis remove sugar from your sap?
No, reverse osmosis doesn’t remove sugar from your sap. In fact, the reason we want to run sap through an RO is the exact opposite. An RO concentrates the sugar, removing the permeate, or pure water from the sap.
By concentrating the sugar in the maple sap, a sugarmaker can save as much as 90% in fuel since he or she will have to boil the sap for a much shorter time. Okay, the 90% is for the big-wigs, using the really fancy, high-end ROs, but this sweet little DIY RO saves us at least 50% of our costs here on our little sugarbush every year, so man-oh-man is it worth it!
Can you run sap through RO twice?
Yes! Not only can you run your sap through your RO twice, but I highly recommend it!
You’ll save yourself that much more on fuel costs to boil down your sap, since you will have doubled the amount of water you’ve removed, but you also may notice a slightly more caramelized taste to your syrup. That’s a win-win in my book.
Does a DIY RO system really save money?
Our family lives on 14 wooded acres, and we cut and store a lot of wood. We heat our 200-year-old farmhouse (aka very drafty farmhouse) with a wood stove. All winter. All very-long-cold-New-England winter. There just aren’t enough hours in the day or trees in the woods to do it all. So we persoanlly choose to boil our sap with propane.
But whether you’re a backyard sugarmaker who uses propane or wood for fuel, a homemade ro system will save you a boatload of time and money. (Read about Ray Ingham’s ro experiences below.)
Afterall, we all wanna save on fuel, no matter where were get it, can I get an “amen”?
Of course, no matter what you use for fuel, cuddling with a barn cat while you watch the sap boil makes everything a little more puuurfect. (Sorry, bad pun.)
If you wanna read more about why we RO, go here. Wanna know how we even do some natural RO for FREE? Read this article right here. Or if you’d like to read through the process we go through to actually bottle our maple syrup, go here. Otherwise, read on…
Is it hard to build a DIY Reverse Osmosis system?
Here’s our Reverse Osmosis set up. It’s rather simple, it’s rather small, but it’s totally huge on savings.
How long does it take to build your own Reverse Osmosis (RO) system? Honestly, getting all the pieces is the largest drain on your time. Once you have all the parts in front of you, it’ll take you a few hours, tops. Well, that is if you’re like Bill. If you’re like me. . . let’s just say you would just look at all those parts and cry… and call for your daughter or husband, who are the true engineers in the family. . . then go bake some maple cookies while they do the hard work. (If you need a giant cookie fix–and I do mean giant–you’ll want this recipe.)
How long does it take for a 5-gallon bucket of sap to go through the system? We use filters intended for 150 gallons per day, and 5 gallons goes through in about 45 minutes.
At what pressure do we run our RO? We run it at 60-70 psi, which we regulate with the needle valve.
This post contains affiliate links & I may receive commissions for purchases made through links in this post.
Go here to read the full (ultra fun) legal disclosure about that.
To build a reverse osmosis set up of your own–and seriously slash your fuel costs–you’ll need a piece of plywood, or something similar, for mounting everything, and you’ll need the following items, which are all pictured below as well, in the order they’re listed. Click either the item name or the picture for ordering information.
Then keep scrolling for a totally unprofessional, hope-you-understand-what-he’s-talking-about drawing of Bill’s design.
The items we used for our DIY Reverse Osmosis for making syrup
Pump and transformer, membranes* (you will need 4 but see other links for varying gallons per day), membrane casings (4), filter 4-pack, filter housing, pressure gauge, a straight needle valve.
* For your membrane, you can choose the one linked above, for 50 gallons per day, or upgrade to one for 100 gpd or 150 gpd. (We use the 150 gpd filters. We have 110 taps and process roughly 5 gallons of sap through the RO every 45 minutes.)
btw, if you don’t already have Amazon Prime, I highly recommend it. We live in nowhere-ville, so traveling to Lowes is quite a trek. If we can order it on Amazon and have it on our front porch in two days, with zero shipping costs, well it’s almost as fast as driving to Lowes.
But seriously, you can try out Prime for totally free for 30 days. If nothing else, sign up and get all these goodies delivered to your door for free shipping, right away, so you can start saving money on your propane.
Try Amazon Prime 30-Day Free Trial
You’ll also need some tubing and connectors, as well as another valve. These items, which I couldn’t find on Amazon, I list below, along with where I did find them and the item #s or purchasing info you’ll need.
The items we picked up at Lowes for our DIY Reverse Osmosis system
1/4″ T (you’ll need 4 of them) Sharkbite item # 835039, model #25427Z
1/4″ male x 1/4″ quick connect 90° (you’ll need 5 of them) Sharkbite item #83500, model #25433
1/4″ male x 1/4″ quick connect straight (you’ll need 8 of these) Sharkbite item #835025, model #25413Z
3/8″ x 1/4″ male quick connect (just 1) Sharkbite item #835028, model #25416Z
3/8 polyethylene tubing (25′ of it) item #879277, model #98634
1/4 polyethylene tubing (25′ of it) item #814305, model #98584
3/8″ quick connect ball valve (just 1) Sharkbite item #835049, model #25438Z
ridgid 3/8″ x 30″ pex tube (30″ faucet) item #751655, model #7227-30-38-2
Here’s the artwork I promised you.*
*NOTE: the red lines in Bill’s drawing represent clear tubing connecting the filters in sequence above. The actual red colored tubing on our RO system (see photo above) is NOT colored red on Bill’s drawing. Sorry if that is confusing. Bill confuses me sometimes too. 🙂
How much water does reverse osmosis take out of maple sap?
In the end, a DIY Reverse Osmosis system will take a lot of the water out of your syrup. We typically run our sap through a few times and get our sugar concentration up to about 8% (vs. the 2% we start with). We’ll take 100 gallons of sap down to about 40 gallons of sap before we start to boil it into syrup.
If you want to know more about choosing a refractometer that will help you measure your sugar levels of your sap so you know how much more concentrated your RO system is making your sap, read & watch the video here about How to Make Syrup–what tools do you need?
Is Reverse Osmosis worth it for maple syrup?
Yes, the afternoon or two that it will take you to build a DIY Reverse Osmosis system, and the money you invest into the parts will absolutely pay you back in the long run. Depending on how many trees you tap, it will most likely pay for itself in just a few years.
Read a few reviews of this system below to see the return on investment others are reporting. It really is a great investment that pays off quickly.
What are people saying about this DIY RO system?
Mark & Colleen Falardeau, backyard sugarmakers who built this RO system, explain,
“It cost us roughly $300 to make our RO and it takes sap from 2-3% sugar content to 7-8% in one pass! We have 100 taps and the wood saved and time saved in one season has made it worth every penny!!“
Chris M. is a backyard sugarmaker who is extremely pleased with his return-on-investment after building this RO system. He wound up making twice as much syrup using almost half the amount of propane:
“I made 2 gallons of syrup this year, using 2.5 tanks of propane. How does that compare to my costs last year? Last year, I made about 1 gallon of sap and used 4(!!!) tanks of propane. That is insane return on my investment!“
Ray Ingham is a hobby sugarmaker in Huntington, Vermont. Ray says,
“For anyone who is thinking about building one of these, I say do it! I put one together last year using 4 100 gpd membranes. It cost me about $350 and was well worth it. I’m retired and a one-man band. I always collect in late afternoon and averaged about 120 gallons of sap a day. I would run the RO over night and extract about 7 gals. of pure water an hour. By morning I would have 30 – 40 gallons of sap to boil down. My sap went from 1.5% sugar to 4 to 5% sugar after running through my ro. I would boil this down in less than 3 hours in my 2×4 pan. I saved a incredible amount of time and firewood.”
Heather Gilson, whose family has about 50 taps in their backyard on any given year, explains,
“My husband built one last year and man was it a time saver for us!! We saved so much time in not splitting a bunch of extra wood, not having to boil for extended periods of time. It was amazing!”
How do you clean RO membrane for maple sap?
You’ll be surprized at how easy it is to clean your RO membranes and use them for many seasons.
To clean the membranes after each use: Simply run your permeate (the water that your system pulls out of your sap) through your system at the end of your day. That will be all the membranes need to be clean and ready to use the next day.
To clean the membranes at the end of the season: Simply remove your membranes and wash them under running water thoroughly. Place them in a ziploc bag and store them in the back corner recesses of your refrigerator until the next sugar season.
More syrup-related information:
How to use pumps to make your sap collection so much easier
My detailed list of all the best tools for a backyard sugarmaker
Make some amazing Maple Cream with your syrup
You can also follow my Maple Syrup pinterest board right here. Everything I ever write about maple gets added to that one board.
Taste and see that the Lord is good. Psalm 34:8
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How do you clean the membranes for storage off season? Do you clean the system during the season and if so what do you use?
At the end of every season, we run 5-10 gallons of permeate through the system, then we remove the filters from their casings and mark where each filter was in the system (so we can change their position each year, to hopefully give them a longer life) Then we put them in a ziplock bag and store them in the refrigerator until the next sugar season. When it’s time to start up the RO again the next year, all we do is take the filters out of the fridge and use them. We never need to clean them during the season, but every time we use it we run some permeate through the system before shutting it off for the night. Hope that helps.
Thanks for the instructions and parts list. I just received all the parts today and hope to assemble over the holidays. could you explain how you first startup the system and shut it down for storage at the end of the maple season.
At the end of every season, we run 5-10 gallons of permeate through the system, then we remove the filters from their casings and mark where each filter was in the system (so we can change their position each year, to hopefully give them a longer life) Then we put them in a ziplock bag and store them in the refrigerator until the next sugar season. When it’s time to start up the RO again the next year, all we do is take the filters out of the fridge and use them. I hope you LOVE your RO and all the money it saves you!
Do the filters NEED to be kept in the fridge? Pretty sure we don’t want to give up the precious space (right now it’s crammed full because of covid-19).
I did find this suggestion for the seasonal storage of RO membranes:
“Storing your membranes in the off season:
The easiest way to do this is to make PVC vessels. 3” PVC pipe works well – I made 2 – 40″ canisters because they are easier than one long one. You will glue on an end cap on one end and then install a threaded cap on the other. Plan on doing this well ahead of time. It took about a week of rinsing with water to get the smell from the pvc primer and glue to go away. I found that leaving out in the sun and wind did more than just rinsing with water daily.
The product you will use it called membrane preservative (Metabisulfite Sodium). The mix ratio is 1.1 ounces to 1 gallon of permeate. I fill up my PVC vessels with water and measure how much they hold so I know how much solution to make.
Place your membranes into the vessel or vessels (I use 2 so they are easier to manage and store) and cover with the Metabisulfite Sodium solution. Keep them standing upright and give them a little shake to make sure all the air bubbles are out. Cover and let stand overnight. Open the tops and add additional solution if needed. Give a couple of wraps of teflon tape and seal. Keep them from extreme heat and freezing and they will be safely stored until next season.
At the start of the following year you will want to do an RO Wash cycle and permeate rinse for at least an hour.”
Their cleaning regimen seems a bit extreme though.
Thanks for the great instructions. I’m still a little unclear on the cleaning procedure after each run during the season. Do you run the permeant through in reverse to flush?
Hi Scott. Every evening during the season, when we’re done RO-ing for the day, we simply run the RO one more cycle, using permeate instead of sap. The permeate cleans out the filters. Are you building your own RO for this year? If so, I hope you love it. (And all the money it saves you!!)
I am going to give it a go. I’m assembling the RO system now, and everything is going great. I only have 40 taps, but if this works I will tap more. Boiling has been my limitation in the whole process for both time and fuel reasons. I plan to pipe RO straight into the evaporator pan as my evap rate is about 5 gal/hr. This way I don’t have to add another tank. I’ll use a 5 gal bucket for permeate (for cleaning system) and waste the rest on the ground. I’m in Wisconsin, and I have a brother who also makes syrup in Vermont. Wisconsin has won every family taste test (blind of course). He has 400 trees.
Have you noticed your syrup having a Different taste when you started using an ros system. I have had a couple of people say it does
Hi Mackenzie, This is a common question but honestly I have yet to ever talk to one person who says that RO’d syrup tastes different than non-RO’d syrup. Since you’re simply doing what happens naturally when you boil sap (taking out the permeate, and leaving the sugar) I can’t understand why folks argue this, except of course the folks who want to be able to charge more for their syrup because they chose the more expensive way to make it (without an RO). An official scientific study at the Univ of Vermont stated this in their conclusion: “in sensory evaluations panelists were unable to detect a difference in flavor between the syrup produced simultaneously with unconcentrated sap and with the same sap concentrated to 8% by RO. The results indicate that producing syrup with sap concentrated by RO does not have a significant impact on syrup chemical composition or flavor.” Hope that helps. 🙂 btw, you can read the full report in my Subscriber Resource Library… Join here if you’re not already: https://soulyrested.com/snag-free-ebooks/
Does any body know what pressure setting to use when running permeate thru for the daily cleaning?
While researching, I’ve read about some RO systems running at 100 – 110 PSI, however this system runs around 60. Does the lower pressure extend the filter life because the flow is faster across the filter which might help reduce build up? Any thoughts or comments?
Thanks, Bob
Hi Bob, I just asked Bill. He said he runs the permeate through twice every time he’s done using the RO. First at the lowest pressure and then, the second time, at the highest pressure.