How much wood does it take to make a gallon of maple syrup?

On a real evaporator, roughly 1/20 to 1/30 of a cord: published figures run 19 to 30 gallons of syrup per full cord. On an open pan over a block arch, several times that; the Wisconsin survey average works out to about 1/10 of a cord per gallon.

Is propane cheaper than wood for a backyard boil?

Rarely. A turkey-fryer burner under an open pot wastes most of its heat, and Cornell warns the propane bill can approach the value of the syrup. Purpose-built LP evaporators ran about 5 gallons of LP per gallon of syrup in the 1977 study.

Dry hardwood. At 20 percent moisture sugar maple holds about 21.3 million BTU per cord, white ash 20, red maple 18.6; hemlock (13.5) and white pine (12) burn hot and fast but carry about 40 percent less heat per cord. Season it 9 to 12 months and split it small.

Calculator · 20–30 gal per cord

How Much Wood or Propane to Make Maple Syrup? Fuel Calculator

Enter the syrup you expect to make and how you boil. The estimate uses the published figures: gallons of syrup per cord on a real evaporator, the Wisconsin open-pan survey for hobby rigs, and the oil and LP figures from the fuel studies.

Syrup you expect to make

gal

About a quart per bucket tap in a typical season.

How you boil

Fuel

Dry hardwood, open pan

about 1.0cords

From the 2003 Wisconsin survey average of 2.1 million BTU per gallon for wood boilers, at sugar maple's 21.3 million BTU per cord; the survey range ran 170,000 to 5.3 million

The 2022 manual plans on 1 cord per 75–100 taps for an efficient rig. Open pans waste most of the heat, so the hobby figure is several times higher. The fuel guide →

These are planning figures from dated sources (1977–2022), stated with their years on the guide page; dry wood, a tight arch, a preheater or RO move them a lot.

How it works

The math behind it

On a conventional wood evaporator, published figures run from about 19 gallons of syrup per cord at 30 percent efficiency (2006 Producers Manual) through 22 (Ohio State, 2021) to 25–30 (USFS cost study, 1977 data); the 2022 manual plans on 1 cord of dry hardwood per 75–100 taps.

Open pans are far less efficient. A 2003 Wisconsin survey of 62 producers found wood users averaging 2,100,000 BTU per gallon of syrup against 331,000 for oil and gas, with a range from 170,000 (preheater and RO) to 5,343,000; Ohio State puts the theoretical need from 2 percent sap at 400,000 BTU. The open-pan figures here convert that average with sugar maple's 21.3 million BTU per cord or propane's 91,500 BTU per gallon.

Oil: more than 3 gallons per gallon of syrup on traditional rigs (2006), 3.5–4 in the 1977 study, about 1 with reverse osmosis and heat recovery. Propane: about 5 gallons of LP per gallon of syrup on purpose-built LP evaporators (1977). All of these are planning numbers; dry wood, draft, preheaters and RO move them.

FAQ

Common questions

How much wood does it take to make a gallon of maple syrup?: On a real evaporator, roughly 1/20 to 1/30 of a cord: published figures run 19 to 30 gallons of syrup per full cord. On an open pan over a block arch, several times that; the Wisconsin survey average works out to about 1/10 of a cord per gallon.
Is propane cheaper than wood for a backyard boil?: Rarely. A turkey-fryer burner under an open pot wastes most of its heat, and Cornell warns the propane bill can approach the value of the syrup. Purpose-built LP evaporators ran about 5 gallons of LP per gallon of syrup in the 1977 study.
What wood is best?: Dry hardwood. At 20 percent moisture sugar maple holds about 21.3 million BTU per cord, white ash 20, red maple 18.6; hemlock (13.5) and white pine (12) burn hot and fast but carry about 40 percent less heat per cord. Season it 9 to 12 months and split it small.

LuckySap · free on iPhone & Android

Your whole season, logged

LuckySap keeps every collection and boil in one place: sap totals, sugar readings, sap-to-syrup ratios, and a season you can compare next year. Free on iPhone and Android.