Smoky flavor can sneak into maple syrup boiled over an open fire because the smoke and debris from the fire pass over the sap as it boils. Even if you enjoy this smokiness, it is actually considered a flaw in syrup and could even be somewhat bad for your health, depending on what you burn with. There is no smoke flavor in syrup made in a standard evaporator setup because the fire is isolated from the sap and smoke flows out a chimney. But hey, we don’t have a sugarhouse and certainly no chimney for our evaporator setup and yet our syrup is smoke-free!
First, if you are interested in evaporating maple sap to make your own maple syrup, you need some sort of setup. There are a lot of options, but if you are interested in how we do it, check out this post:
OK, let’s make some clean tasting syrup!
Our tips to avoid smoky flavor in your open fire syrup
#1: Clean out the fire pit before setting the fire
Any leftover ashes from a previous fire could waft up with the heat and settle in your sap. Better to start with a clean slate and avoid this unnecessary extra ash! Removing the ash and coals will also help to improve airflow for your initial fire, since the structure of paper and kindling won’t settle into the mushy ashes. While slightly messy, this is too easy not to do.
#2: Reduce use of newspaper
Newspaper is excellent for getting a fire going, and we use it for every single fire we set, both in our wood stove and in the evaporator. But when burned, newspaper can send up ashes like crazy! These ashes will float around in your bubbling sap and bring strange smoky flavors to your breakfast if you don’t cut back. Our advice is to practice starting fires with less paper to reduce these extra ashes. Transition the fire from the paper to the firewood with good transitional fuels, like birch bark and firewood that is split into small sticks.
#3: Keep the fire hot
A fire kept too cool will be much, much smokier than a nice hot fire. Build it hot and keep it that way! This is also generally a good practice to make sure you have hot fires when heating your house with a wood stove, since a cooler fire will produce more creosote in your chimney.
#4: Use dry hardwoods
Firewood that burns well will be less smoky and you’ll be able to achieve that nice hot fire for the tip above. If you’ve ever tried to burn a softwood like pine or less dry hardwoods, you know how frustrating and smoky things can get. The best woods are hardwoods, like oak, maple, etc., that have been seasoned for 1-2 years or kiln-dried.
#5: Skim regularly while boiling
If you don’t have a chimney to isolate the smoke and ashes from the fire, your sap is going to be mixing with the stuff. If you boil and boil and boil, the smoky aroma from the ashes will infuse the syrup in a way that you cannot recover from. But, if you regularly skim out the ashes with a standard kitchen strainer/sieve, you’ll stop that smokiness dead in its tracks. And it will also improve the speed of filtration later on, since there is less to clog things up. We skim every 15-30 minutes while boiling.
#6 Filter before finishing on the stove
Before we bring our sap inside to finish into syrup after a day of boiling over the fire, we like to run it through filtration. The syrup isn’t fully thickened yet so it will pass through the filter easily, and this gives you a chance to eliminate as much smoky contamination as you can before finishing. And just as with skimming, the final filtration of the finished syrup will be much smoother with less gunk to deal with!