There is an informative article right here in a RIU blog that discusses flavoring weed through the use of flavored extracts. Every time I mention it, I get booed off of the stage, lol.... His reasoning is this, on one of his grows, shortly before harvest, he added fish emulsion as a top dressing to his soil. He harvested shortly thereafter and was horrified to discover that his bud had actually smelled and tasted of dead fish. A light bulb went off over his head and he had his epiphany.
This is the article he wrote...
People pay a lot of money to get seeds they think will grow pot that smells like blueberries or chocolate or something else.
Often these strains are hard to grow or may not be as potent or high yielding as other less expensive varieties.
People want to know if orange bud smells and tastes like an orange. With the proper techniques you can make your favorite variety smell and often times taste like anything you want.
You want to do this without ruining the cure. It's no point having blueberry pot that burns your throat or doesn't get you high. Do not pour any syrup or similar flavorings on your pot. The sugar will make it very harsh and you are inviting mold. There are better ways.
The best flavor enhancing starts while the plant is still growing. You can do a certain amount while it's curing and you can even affect the smell/flavor somewhat after it's been cured.
There are two main approaches, inside out and outside in. You can apply flavors inside the plant while it's still growing and you can try to add flavors after it's been harvested but this is from the outside.
Anything you put in your plants water will affect the taste of the finished product particularly if you harvest it right afterwards.
I learned this about 20 years ago the hard way. I fertilized using fish emulsion right before I topped the plant. Bad move! The resulting top smelled like fish and had a foul taste.
What you want to do is select a flavoring that is very concentrated. Lets take orange for an example. You could use orange juice but if you could find concentrated orange extract you would have less pulp etc to deal with. You will find some concentrated flavor extracts in the grocery store.
Want your pot to smell like vanilla? Vanilla extract is cheap and readily available, so is lemon extract (cooking variety). Other extracts can be found in stores that specialize in baking supplies.
Lets say you can't find any of that and you want to use what you have on hand. I took the example of orange flavoring. If all you have is orange juice you could use that.
I would suggest filtering it first to get out as much of the pulp as possible. A coffee filter works well but it'll take a while to filter it all.
You may have to change filters a few times. Those with hydroponic units will shudder at the thought of a lot of goop going through their system. That's why I suggested the concentrated extracts if you can find them.
It's important to do this shortly before harvest. For one thing, most extracts including the ones you make up yourself have a lot of sugar in them. This sugar will ferment and decay rapidly, even more so in a hydro unit.
With hydro I recommend putting the flavoring in the water between 1 and 3 hours before harvest. This rule isn't set in stone but I heard from one grower who used a sugar based clearing solution on his crop and less than 24 hours later the water was foaming from bacteria growth.
Plants draw up solution fairly quickly so one hour should be enough for some of the flavoring to reach the top.
Three hours should not be enough time for bacteria to grow but you will want to dump out the solution right afterwards and clean out your unit.
If you read the SU of Mar 27 you knew to use plain water for a few days before harvesting your hydro crop so all that will be in the water will be the flavoring.
If you are a soil grower it's even easier. You might think it would take longer for the flavor to work it's way through the plant but this is not the case.
All you have to do is let the plant dry out a little before your apply the solution. In other words schedule a watering just before harvest.
Naturally you were giving your plants plain water for several days to a week or two before harvest weren't you? Give the plant the water with the flavor when it's a little bit thirsty and it will draw it right up. One hour is more than enough time for this to happen.
After harvest it's important to give it a good cure as I described last week. Resist the temptation to fast dry some of the weed to try it out. You will find it's even more harsh than it would be normally because you have added some sugar to the plant by way of the flavoring.
The curing process will take care of the extra sugar and give you nice mild smoke. It will also have the flavor and aroma you are looking for.
Keep the flammage to yourself, I'm merely passing along what I have found in response to the OP