Every fall I make a quantity of fondant trays which I place on hives that need, or may need, emergency food later in winter. The Whole Hive Fondant Feeder tray (click the link to see plans) I use is basically a "candy board" that replaces the hive's inner cover - and is designed such that the requisite hive ventilation is maintained.
The idea is that for those hives that may be short on honey in late winter, I do not have to trek out to my bee yards in February or March and check each of the hives individually. I prefer taking a good guess in late fall as to which hives may need emergency feed and set them up with a fondant tray. Each tray holds about 15 lbs. of fondant... certainly a more than many other emergency feed methods can support (e.g. raw sugar placed on the inner cover).
Left over trays or fondant I give to new hives (splits, nucs & packages) in the spring and summer.
You will note in the above picture that I mention an insulated outer/top cover. All my hives use these. Why? If you ever lived in an old house with single pane windows, you may have noted that moisture in the warm inside air will tend to condense on the cold glass facing the outdoors. The same I believe applies to beehives: the warm, moist air rising from the cluster will condense on the cold ceiling formed by the top & inner covers of the hive. The result may be water droplets falling down on the cluster of bees - not a good thing. Good ventilation will mitigate this to some extent of course. I would rather have my bees a little warmer with less risk of condensation. So, having some insulation will keep the inside of the top cover, and anything that it sits on (e.g. the fondant tray or an inner cover) warmer. This will in turn reduce the chance of condensation.
I must admit wondering though... do bees living inside a tree hollow, presumably without much ventilation, have the moisture condensation problem that many Northeastern beekeepers talk and worry about? hmmmm... What do you think? Just send me an email ...
Fondant (also known as bee candy or bee paste) is used as emergency feed for honey bees - usually in the winter as a defense against low honey stores. Fondant, in solid form, is usually placed on the topmost hive frames where the honey bees can access it as the cluster moves upward in the wintertime.
Fondant in the context of beekeeping is NOT the same as the fondant used by bakers on cakes, etc. Rather, it is mostly "inverted sugar" - sucrose (white table sugar) that is broken down, using heat and a catalyst, into two simpler sugars: fructose and glucose. Fructose and glucose are far easier for bees to digest as these are the major ingredients in honey from which bees get their energy. Although some beekeepers have used baker's (cake) fondant successfully, baker's fondant usually contains other ingredients beyond sugar (e.g. vanilla flavoring and starch which is detremental to the bee's digestive system).
Making your own fondant, while assuring quality, is a bit tedious for beekeepers with many, many hives needing wintertime feeding assistance. On the other hand, it is expected that most hives will have been managed in such a way that additional food (carbohydrates in this case) is not required. Of course, if a hive is in dire straits, one can always try giving the hive granular white sugar (albeit this is not often successful as many of the bees may not be up to digesting it in sufficient quantity or not enough sugar can be supplied via various methods described in beekeeping books).
You will need the following 3 essential ingredients.
The recipe is scalable.
Do not use dark or brown sugar which may be partially caramelized or contain ingredients such as molasses which are detrimental to bee health. Do not use commercial powdered sugar as it usually contains corn starch - not good for the bee's digestive system (also something to remember if you practice using powdered sugar to deal with mites in the spring/summer). Also: avoid using beet sugar (lately showing up in the marketplace) as it is usually from a genetically modified (GMO) plant and possibly containing pesticide residue.
The vinegar acts as the acidic catalysts to foster the inversion of sucrose to fructose and glucose. Vinegar also helps keep the cooled fondant's crystals small so the bees find it easier to ingest and eat. Note that unlike many fondant recipes found in beekeeping books or on the internet, the recipe presented here avoids the following catalysts because there have been reports that they are detrimental to honey bee health.
- Avoid Cream of Tartar because of the potassium content.
- Avoid High Fructose Corn Syrup (HFCS) because it can form hydroxymethylfurfural (HMF) - a honeybee killing compound - when heated above 120 degrees F.
You can use volume of ingredients as an approximation - after you've figured out what weight your containers hold the first time. Different sugar packages have differing densities... I get my sugar in 80-100# re-packaged boxes and consistency of density is not normal. Contrary to popular opinion, it doesn't really matter how exact the water to sugar ratio is at the start. More water is better than too little water and a good place to start is at least 4 parts sugar to 1 part water. Water will be boiled away in the process - achieving the right ratio of the fondant's sugar to water content at the end. More water means longer boil times... that's all. I found that 1:4 (water: sugar) ratio gives the best timing for my personal speed of operation. For the pot I use, the following fills my hive-top fondant feeder (click the link to see plans): 3 lbs. or so water, 12 lbs. or so sugar, 3 to 4 teaspoons vinegar; the result is about 14 to 15 lbs. of fondant.
DON'T FORGET YOUR PROTECTIVE GLOVES and AVOID BURNS!
Many recipes say you have to stir constantly. I don't believe this is necessary - but it helps if you stir a lot at first and after the mixture is well melded, maybe stir every few minutes until it boils. Put a lid on your pot in between stirrings to speed the process (prevent heat loss) and to keep most of the water in place. The boiling point will be around 220-225 degrees F. This step may seem like its taking forever depending upon your heat source. If you get this mixture on your hands/skin, immediately run cold water over the spot for at least a minute. Its a brutal hot sugar syrup burn otherwise!
Important to know: we are now trying to remove water from the mixture (escapes as steam - that's why the lid must be off) until we reach the proper ratio of sugar to water. If you go above this temperature... its OK (the resulting fondant will be harder) but best to turn down the heat to maintain the suggested temperature range.
Check the temperature every so often and adjust the heat source if you have to. Also, it helps to stir when you check temperature to keep the mixture evenly heated in the pot. So... what's this step about? Two things:  The temperature at which the mixture boils relates to the final sugar to water ratio: boiling temperatures in the high 240's or 250's or 260's will produce harder and harder fondant once cooled. Temperatures in the mid to high 230's will produce a softer fondant (albeit still hard to the touch and not soft like cake icing at all) - easier for bees to bite and eat.  Boiling the mixture for 15 or more minutes will actually increase the conversion of sucrose (raw sugar) to fructose and glucose (like honey) - i.e. bees do not have to expend precious energy and enzymes converting it in their stomachs.
This is not critical - You can wait until the mixture is about 180 degrees F. or less to avoid work in the next step. Cooling can seem like forever! You can put the pot in a cold water bath - a kitchen sink filled with COLD water stirring occasionally with the whisk or an electric mixer to even the mixture temperature in the pot. Note: I actually use a trick which greatly speeds the process and produces very consistent results... I add up to 50% more white sugar to help the cooling. Most of this added sugar won't be inverted - but at least 2/3 of the mixture still is...see the picture/process elsewhere on this web page.
DON'T FORGET to make this a healthy meal !
So far we have made a carbohydrate-rich mixture. What about proteins, vitamins, lipids, etc? At this step you can choose to mix in additives: essential oils (e.g. "Honey-Bee-Healthy"), pollen substitute (e.g. "MegaBee", "Bee-Pro"), some of your own (to avoid American Foul Brood) honey, etc. to both entice and certainly boost the health of your bees when they eat the fondant. I consider adding ingredients a very important if not necessary step... especially the pollen or pollen substitute. I use at least 1 to 2 cups per 5 lbs of fondant. Studies have shown that the bee's immune system, life span, and general health is greatly boosted by a protein rich diet. Note that adding pollen substitute may cause your fondant to crystallize/harden much faster than normal - you will have to experiment a bit depending upon quantity.
The temperature when you do this can vary - Usually 165-180 F. degrees or so. The cooler, the faster it sets so MOVE FAST but VERY CAREFULLY!
Place the fondant filled container (e.g. aluminum or paper tray, slit plastic bag) UP-SIDE DOWN (fondant facing bees below!) on top of the topmost frames in the hive. Add an empty super box to surround the fondant container. The super, even a small one, will have lots of air space over and around the fondant container. It is suggested that the space be filled with, e.g. crushed newspapers or some form of insulation Whatever you do, make sure that there is some ventilation: the fondant will absorb some of the moisture produced by the bees in the winter (and actually soften), but care must be taken to insure some airflow up and out as usual. Finally, if the fondant is to be stored for some time, keep it in a dry, cool place. Inverted sugar fondant seems to last at least 6 months.
One final note: remember to remove your fondant (if its still there) in late March when natural nectar and pollen starts appearing (at least in northeastern USA). You want your bees to get excited about what's outside -- more importantly, you want your queen to be stimulated by what the workers are bringing in.