Archive | March 2018

The Art of Tapping Maple Trees

Maple syrup season is in full swing here at the farm.  I tapped three days ago and have filled the 50 gallon boiler tank.  Today is the first day I’ve fired the boiler.  By tomorrow evening we should have over a gallon of fresh syrup if all goes well.  Here at Phoenix Farm we make maple syrup much as the ancestors did hundreds of years ago.

Improvements were implemented over the years with the development of galvanized buckets to replace the old wood ones, better spiels and a more enclosed method of boiling the sap to keep the smoke out.  Syrup was once made in open containers over open fires.  Generally, we collect and process sap much as was done in the 1700s here in New England.  I prefer the old fashioned way.  Besides the nostalgia factor, using metal rather than plastic for long term sap contact alleviates concerns of plastic contaminant leaching.

There is an art to drilling and caring for tap holes using the old methods.  It is helpful to tap on a day when the sap is running so you know the hole is patent.  Dry holes are no good to anyone.  Sap season occurs when air temperatures are in the 40sF during the day and 20sF at night.

I use an antique manual bit and brace drill.  Choosing the correct drill bit size is essential.  Too large or small a hole can lead to tree damage.  The correct size to fit standard spiels is 7/16″.  The spiel must be straight and perfectly round to fit snugly in the drill hole.  The materials required for tapping are the drill, a hammer, a study twig about 6″ long, spiels and buckets with lids.  Some lucky people also have a spiel driver which is a solid piece of metal that fits inside the spiel and allows you to hammer it into the tree without a chance of damaging the spiel.  Someday I will afford a spiel driver!

If the trees are being tapped in mid to late March, try to drill on the more shady northern, northeast or northwest sides of the trunk.  This helps protect the sap gathering in the bucket from getting too hot in the warm afternoon sun.  Sap must be kept chilled or it can spoil.

The hole is drilled with a slight downward slant to encourage the sap to run out.  Too steep a drill angle will allow the spiel to pull out when it holds the weight of a full bucket.  The holes are drilled between two to five feet from the ground.  Trees can be tapped when they reach ten to twelve feet in diameter at chest height.  I put one bucket on smaller trees, two buckets on trees larger than fifteen to twenty inches in diameter.  We have so many trees in the maple orchard that we don’t need to triple tap any of them.  It is safe to place up to four taps on a very large tree.


Drill the hole smoothly and evenly with no wobbling of the bit.  You want the hole to be straight so the spiel will fit flush, containing the sap and sending it out through the spout into the bucket.  Sloppy, loose holes leak and leaky holes are a waste of sap and time.  Drill in about 2.5″ to reach the xylem, where the sap travels inside the trunk.  Use the sturdy 6″ twig to clean any drill dust out of the hole.  Then, use the hammer to gently tap the spiel on the wide area above the spout to drive it into the hole until it is just snug.

A spiel driven in too deep can split the trunk, greatly damaging the tree.  A spiel that is too loose is in danger of falling out when the bucket gets full.  When the sap starts to run out the spout, I clean the first of it away since it will be full of bits of drilling dust.  Finally, hang the bucket on the spiel and pop on a cover.  It takes me four to five minutes to complete each tap.



On a nice, warm afternoon in March when the sun is shining and the temperature is around 45F, the sap will practically pour from the drilled hole. Each tap hole produces between one to two gallons on a day when the sap is running well.  Temperatures below the 40sF, cloudy, cool days and chilly, windy days reduce sap production.  
After the trees are tapped, (we have twenty-five taps this year,) it takes two to four days to collect enough sap to fill the boiler pan, depending on the weather. The average ratio is forty gallons of sap produces one gallon of syrup. I suspect the soil in our maple orchard encourages very robust trees because they gives us a little more syrup per gallon of sap. More like 35:1.

Once temperatures are sustained above freezing at night, the maple trees begin to bud:  their leaf and flower buds are swelling in preparation for opening.  Budding signals the end of syrup season.  The sap becomes dark and bitter.  To me, care of the tap holes at the end of the season is as important as at the beginning.  Certainly, there are plenty of people who will swear that all you need to do is pull out the spiel and let the tree alone.  The sap that bleeds out in profusion from the holes is not a problem for the plant, some claim.  I ignore this advice.

It makes sense to me that a bleeding tree is losing energy.  It also is obvious that an opening that leads 2.5″ into the trunk of a tree is an invitation for insects and microbes to invade.  At the end of the season, I use the hammer to gently tap each spiel out of the tree.  I cut ash saplings selected to fit snugly in the opening.  Using ash rather than maple saplings reduces the chance of introducing disease into the tree.

I peel and whittle the sapling, as necessary, until it perfectly fits the hole.  Then I cut off a piece about 1″ long and tap it into the hole.  The chunk of sapling acts as a plug.  It greatly slows the loss of sap.  As the tree heals, new wood forms inside the hole and pushes outward against the plug, popping it out of the trunk.  Filling the hole completely with foreign wood so that the plug remains in the tree will damage the plant since it creates a dead space in the trunk.  In the photo above, the plug placed last year is on its way out of the hole.  Below is a well healed old tap hole.

Improper drilling can create catastrophic results for the tree.  When a tap is driven in too hard and the trunk splits, the wood below the hole dies.  A wide section of the truck is lost, resulting in a hole in the tree near the roots and much dead wood.  When I first started tapping maples, I made the mistake of splitting the trunk a few times and damaged several trees including this fairly young one below.  There is a big hole on the left lower side.  This tree still produces plenty of sap and is healthy, but some do not recover from the damage.  They are weakened to the point where they have to be cut down.

One of the joys of maple season for me is listening to the sap drip into the metal buckets.  Quite a cadence can be heard of a warm afternoon.  So that others might enjoy this rare tree music, I’ve made a couple short videos of the dripping sap.  Notice in the close-up shots how the hydraulic force appears to create a heartbeat-like rhythm.

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