Home-grown organic corn syrup.

In the farming season, I find that when a customer asks me what my favorite vegetable is I often answer with whatever has just ripened and is freshest at that moment. In early spring, it’s bok choy; in June, snap peas; in July, I love summer squash (but only because I’m not sick of harvesting it yet); in August, it’s the first fresh tomatoes that steal my heart. But of all the harvests I look forward to, there’s none that quite compete with the anticipation of the first corn syrup of the season. When the weather cools down and the wind starts to rustle through the partially dried corn stalks, I make my way out to the fields for the first tappings.

The process of growing your own organic corn syrup is a little labor intensive, but it’s worth it if you want to get this home-grown, high quality sweetener – which, believe me, you do. There are a few pieces of the process that are key to your success, so please read on if you’re interested in growing this specialty crop.


Variety Selection

Setting taps in the fall.

The first step to harvesting good corn syrup is appropriate variety selection. The varieties you select will determine if you harvest regular corn syrup or high fructose corn syrup. This difference is determined by the corn’s genetic type, which you can read about on page 22 of our 2019 seed catalog. Basically, standard (su), sugary enhanced (se) and tablesweet (se+) corns result in a regular corn syrup harvest. The more advanced genetic types like synergistic (sy), supersweet (sh2) and augmented (augmented sh2) result in a high fructose corn syrup harvest. I find that regular corn syrup is enough of a sweetener for me, since I tend to only use it to lightly sweeten my coffee, and in the occasional pie around the holidays. But for those of you with a serious sweet tooth, a high fructose corn syrup variety might be the best choice.


When to Plant

In order to establish enough sugar content in the corn stalks to reap a good corn syrup harvest, you’ll want to plant as early as you can, though the soil needs to be at least 65°F for good germination. I like to direct seed, as it saves me time and propagation space. Even in our short seasons here in northern Vermont, we still have enough growing time to yield a good syrup harvest in the fall from a direct seeded crop. Treating the corn seed by soaking it in corn syrup for a day before planting (using the last of the previous year's harvest works great for this) will help give the seed a jump start for germination and vigor.


When to Harvest

Harvesting sap.

As soon as the nighttime temperatures dip below 30°F, you’ll want to set your first taps. The cool weather signals the plants to start moving sugars from their mature ears back down into their root systems, and that’s when the sap really starts flowing. In good harvest years, when the weather is just right, you’ll be able to harvest for 3-4 weeks before a good hard frost knocks the plants down for good.



How to Harvest

The harvest of home-grown corn syrup takes a few special tools, but they can be easily found at your local hardware retailer, box store, or even kitchen supply outlet. You will need:

  • Miniature maple sugaring taps
  • Miniature maple sugaring buckets
  • 5 gallon buckets (for collecting into)

I was able to fashion my own taps to make them look like corn on the cob holders, which adds to the charm of harvesting. Plus, it was a good winter project. Simply tap the base of each corn stalk, roughly 1.5-2 feet above the ground, and carefully hang a bucket from each tap.

The miniature buckets will fill up with sap about twice a day in the height of the harvest season. So, you’ll be kept busy during those 3-4 weeks when the sap is really running. Once you have collected your sap, it’s time to start boiling.


Boiling Sap to Make Syrup

Boiling sap.

The length of time you boil your harvest will determine the grade of your corn syrup, ranging from light (~12 hours) to dark (~18 hours).


Boiling can be done on a stovetop, woodstove, or an outdoor fire pit. Your setup will depend on your scale, and of course your staffing. Since the boiling process takes so long, you’ll need to make sure you have someone watching the heat source at all times.

Simply fill a large pot roughly ¾ full with sap, and boil it down until it is ¼ - ½ its starting volume. Then you can start to add more sap, but try to maintain a constant boil. As the volume decreases and the sap thickens to syrup, you can start transferring to smaller and smaller pots until you’ve reached your desired grade.

As I mentioned, growing your own corn syrup is a little labor intensive, but the result is a stash of delicious home-grown corn syrup for the rest of the year.


Happy April Fools’ from High Mowing Organic Seeds!