When to Feed Sugar Syrup to Honey Bees
Feed sugar syrup only when a colony assessment reveals inadequate honey stores and ambient temperatures permit liquid feeding. A light hive in early spring, a newly installed package drawing comb foundation, or a nucleus colony during a summer nectar dearth may need supplemental carbohydrate feed. Strong colonies in an active nectar flow should not be fed syrup.
Important harvest limit: Never feed sugar syrup while honey supers intended for human consumption are on the hive. Bees will store inverted sugar syrup alongside nectar in the surplus supers, adulterating the harvested honey. Before feeding, always consult a seasonal management plan such as our guide to sugar water for bees or the urban beekeeping calendar.
Sugar Syrup Reference Table (by weight)
Apicultural research requires measuring syrup ratios by mass. A standard kitchen scale is the most accurate tool for mixing. The table below shows required clean water and total batch mass for common retail sugar quantities:
| Sugar Package | Ratio | Clean Water (Mass) | Approx. Water Volume | Total Batch Mass |
|---|---|---|---|---|
| 4 lb bag (1:1) | 1:1 | 4.00 lb | 0.48 gal | 8.00 lb |
| 4 lb bag (2:1) | 2:1 | 2.00 lb | 0.24 gal | 6.00 lb |
| 10 lb bag (1:1) | 1:1 | 10.00 lb | 1.20 gal | 20.00 lb |
| 10 lb bag (2:1) | 2:1 | 5.00 lb | 0.60 gal | 15.00 lb |
| 2 kg bag (1:1) | 1:1 | 2.00 kg | 2.00 L | 4.00 kg |
| 5 kg bag (2:1) | 2:1 | 2.50 kg | 2.50 L | 7.50 kg |
* Water volume equivalents assume pure water at room temperature (~1.00 kg/L or 8.34 lb/gal).
How to Prepare Syrup Safely
- Use pure white granulated cane or beet sugar: Plain table sugar is 99.9% pure sucrose and is safe for honey bees. Never use unrefined brown sugar, raw sugar, molasses, or powdered sugar, as the mineral residues and starches can cause fatal honey bee dysentery.
- Heat water before adding sugar: Warm clean potable water in a pot until it is hot enough to dissolve crystals easily. Remove the pot from the burner or heating element before adding the sugar.
- Do not boil or caramelize: Never boil sugar syrup. Excessive heat can caramelize sugar and produce hydroxymethylfurfural (HMF), a compound that is toxic to bees.
- Cool completely before feeding: Hot syrup can scald bees or melt plastic feeder components. Let feed reach hive temperature before introducing it.
Preventing Robbing in Urban Apiaries
The scent of sugar syrup during a nectar dearth can trigger intense robbing behavior in urban neighborhoods, where colonies live close together. To avoid robbing:
- Use internal feeders, such as frame feeders or enclosed top hive feeders, rather than external Boardman entrance feeders.
- Reduce hive entrances using wooden entrance reducers before placing feed on small or struggling colonies.
- Fill feeders in the late afternoon or evening when flight activity is winding down.
- Clean up any spilled syrup immediately with clean water.
Frequently Asked Questions
Why can't I just use measuring cups (volume)?
Granulated sugar contains air pockets between crystals. A dry cup of sugar weighs approximately 7 ounces, while a cup of water weighs 8.3 ounces. Mixing "1 cup to 1 cup" creates a 1:1.2 ratio rather than a true 1:1 mixture. A kitchen scale ensures precise caloric concentration.
How long does mixed sugar syrup last?
Thin 1:1 syrup ferments and molds rapidly in warm weather. Mix only what a colony can consume within 2 to 3 days. Discard any batch that smells sour, appears cloudy, or develops mold spots. Wash feeders thoroughly between batches.
Should I add essential oils, vinegar, or acid to invert the sugar?
No. Healthy bees produce enzymes (invertase) in their hypopharyngeal glands that break sucrose into glucose and fructose. Adding acids (like lemon juice or cream of tartar) under heat promotes HMF formation. Plain granulated sucrose in potable water is the safest feed.
Also planning your honey harvest? Use our Honey Jar Calculator to calculate jar fills and packaging requirements.