Tag: maple

Maple Evaporator Build

We built our maple evaporator — well, combination fire table, maple evaporator, grill, and smoker all-in-one backyard fire contraption. Scott calls it the MapleAtor. Total cost was about a hundred bucks — $60 for refractory brick, about $10 for the cinder blocks, and about $30 for “engineering” size brick (and probably another hundred bucks in fuel to *get* the blocks and refractory brick!).

We’ve got a layer of cinder blocks on the base — four rows five blocks long. Since we had four half-blocks, we were able to stagger the walls. Nothing is mortared together yet — we wanted to make sure it was a good size, shape, and location before we made anything permanent.

Two rows of fire brick lay atop the cinder blocks — we wanted to be able to set the 6″ steam table trays that we use to evaporate sap onto the cinder blocks and seal the fire section in so the syrup doesn’t get smoked as we evaporate it. The dimensions didn’t quite line up — we needed something 2 3/4″ high to fill in the gap between the edge of the refractory brick and the edge of the cinder block. I happened across “engineering” bricks online, and we found a company that sold them. They fit perfectly.

Once the base layer was covered in refractory brick and red brick, we started stacking the walls — more cinder blocks.

 

Along the back wall, we have some bricks forming a wall, but we have one row slightly pushed in so a block can straddle the two bricks and form an exhaust area. Then a bunch of blocks are stacked up to form a chimney.

The evaporator trays fit perfectly and are supported by the cinder block.

We ended up re-stacking the chimney — having the exhaust port at the same level as the refractory brick meant that pushing wood around in the fire box shoved coals out into the chimney. The exhaust port is now one row higher than pictured.

We then lined the firebox with more refractory brick — there are two or three inches between the top of the refractory brick and the bottom of the evaporator trays. Adding logs and lighting a fire, we finally have maple sap evaporating.

We added a steel plate at the end of the trays to keep smoke away from the sap.

Bonus — we can cook dinner while we’re evaporating sap!

Maple Tapping

Instead of taps with a hook for a bucket (which seemed, to me, like it would put a lot of stress on the tree!), we use ratchet straps to hold our maple buckets. One end of the “S” is passed into the fabric loop that holds the other “S” — and that other “S” becomes our bucket hook. I like the bright orange straps because it makes finding trees in the woods very easy (bright white buckets look obvious too, but they can hide behind the tree).

Our first set of buckets has large holes drilled into the lids — which are great for larger trees with multiple taps. But the new buckets we bought this year have tube-sized holes to prevent rain from leaking into the bucket.

2023 Maple Season – First Sap Collection

We tapped trees for the last few days and have our first sap collection — thirteen five-gallon buckets (not completely full, but around 4.5 gallons per bucket … so not 65 gallons but at least 58.5 gallons) waiting to run through the reverse osmosis.

This year, our starting sap measured around 1.006-1.008 SG at around 50 degrees. The reverse osmosis is running at just under 100 psi (at 100 psi, we are not getting any sugar water out). The output sugar water is measuring at 1.022 … which is 3.7 times as concentrated as before we filtered the sap.

The flow rate is about a gallon every ten minutes, or six gallons an hour.

Maple Sap Reverse Osmosis

Since I had the reverse osmosis system laid out for assembly, I figured I could take a picture to show how the filters are connected in series. Each filter “cleans” water out of the maple sap — that water is fed into a common output tube where we collect gallons of water (the clean water output lines are removed here so we can see the path maple sap travels, ignoring the clean water). We use this water for rinsing sappy stuff as we collect, filter, and boil the sap … also water we drink, bring out to the chickens and turkeys, give the cat, dump in the washer.

The “dirty stuff” that normally gets discarded? That’s the concentrated sap — each filter’s “dirty stuff” line is connected to the input of the next filter. Which then “cleans” more water from the sap and passes the “dirty stuff” down the line.

The maple “setup” is the reverse of the “drinking water” setup — below — where the “dirty stuff” goes to a common drain line for disposal and the clean water is sent to the input of the next filter for farther cleaning.

2022 Maple Season

Well, the 2022 maple season is over — I think our taps have dried up because we’ve had a few freeze/thaw days and haven’t really yielded an appreciable amount of sap. We only got like 2.5 gallons of syrup this year — much less than expected … and we need to be ready to tap in January next year when the first week of freeze/thaw hits. While I love the flavor of late-season syrup, we’re getting way too many warm days in March for good sap production.

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 Butterscotch

The maple butterscotch topping I made for Scott’s cake was quite simple — 2/3 cup of heavy whipping cream, 4 Tbsp butter, and 1 cup of maple syrup. Melt the butter in a pan, then mix in the whipping cream. Add maple and boil until it’s really bubbly — sauce will thicken on the back of a spoon when it cools.