A liquid is not an object
You touch one object that is no larger than 10 feet in any dimension.
So the question comes down to: would a liquid count as an object? The rules define an object on page 193 of the DMG:
For the purpose of these rules, an object is a discrete, inanimate item like a window, door, sword, book, table, chair, or stone, not a building or a vehicle that is composed of many other objects.
A liquid, even a highly viscuous, supersaturated one such as liquid honey seems to be a bad match for this rules description. None of the objects in the description here or in the object size table are even remotely is similar to a liquid.
Is hard to even imagine how to add a liquid to this list. What would you add, "a water", or "a honey"? At best you could add a jar of honey or a honeycomb, at which point the object-ness comes from the jar or comb, not from the liquid, or a lump of honey (if the honey is crystallized).
Objects have AC and hp
The DMG provides rules on p. 246 for assigning AC to objects, because objects can be attacked. However, there is no liquid listed among the AC materials. Also, the DMG says on p. 247
Hit Points. An object's hit points measure how much
damage it can take before losing its structural integrity.
It is unclear what the structural integrity of a pool of water would be. So the lack of probable AC or hp would also indicate that a liquid cannot be an object.
Maybe one could argue that the "structural integrity" of a liquid is just not being evaporated, or splashed apart.
The other issue with a liquid as an object with hp is that by attacking it you should be able to reduce those hp. You can hit a pool of liquid with a sword as much as you want without leaving any permanent damage. One maybe could explain this as immunity to most damage types, including bludgeoning, slashing and piercing, with only fire damage able to evaporate it.
Object = one discrete item
An object is a discrete item, in singular. So you only can cast it on one item. It would not work on something you have "any number of". If you had one crystallized piece of honey, it would work. Discrete is defined in the dictionary as "clearly separate or different in shape or form".
A liquid is not a single, discrete item on both counts (and either one would be sufficient to disqualify a liquid as an object):
First liquids are not one thing, but countless tiny things attracted to each other. You can see this by how easily they separate into spray, droplets, spills, and reunite without leaving any trace that something changed. If you touch part of a volume of liquid, you do not touch a single item. One could maybe argue this is using a modern physics interpretation, and D&D is not a physics (or chemistry) simulation, and that a puddle could be considered one thing.
Second, liquids have no defined shape or form other than that imposed by their container. If you spill them they lose their shape entirely, so they are not discrete in having by themselves a clearly separate form. They do however have a boundary, if at rest, and could be considered discrete in this regard.
What are the consequences of not treating a liquid as an object? One would be that you cannot ingnite a puddle of oil with a flaming sphere or fire bolt, an outcome that is highly counterintuitive. But what about cone of cold? It affects only creatures, so it would not freeze a puddle of water either, if you follow the rules strictly, which is just as unintuitive.
Ask your DM
In the end, the fact that other answers argue vehemently for liquids being objects means there is some room for interpretation of the written rules text. So this will be up to your DM to rule on.
I agree with Jacks's answer, if your DM agrees to it, it would not seem unbalancing, and might be quite fun to allow casting light on a lump of semi-crystallized honey that you could smear onto someone. Or even on the water in a crystal decanter, as long as it retains its shape and is not spilled.
You also could cover an object like a small coin with a sticky substance, cast light on it and throw that, which would not require DM agreement, and would be functionally equivalent.
(PS There is a related discussion on what counts as an object in general.)