Elderberry and elderflower both come from the same plant and have many of the same nutritional benefits, but they don’t have the same compounds and are not used in the same ways. If you want to know how to use these two parts of the elder plant, read on below.
How does elderflower differ from the elderberry?
Aside from the fact that the flower and the berry are two different parts of the plant, the first and most distinctive differences between elderflower and elderberry that you will notice are the areas of flavor and aroma. The consensus for elderflower is that it is a combination of some of the most pleasant sweet aromas in nature. It is intensely floral and contains notes of passionfruit, citrus, and vanilla. In comparison, the elderberry is mainly fruity and tart without most of the aromatic elements that you can detect in elderflower.
Elderflower 
Elderberry
Elderflower’s sweet aromas tend to go away when it is cooked for long periods, which is why most of the elderflower applications that involve heat it don’t have long cooking times; elderberry’s notes tend to stick around, which is why it works in jams that have to be cooked for a long time.
Elderflower is not toxic, but elderberries are since they contain cyanogen glycosides. It is strongly recommended that you avoid eating them raw. It is even more strongly recommended that avoid eating unripe or under-ripe elderberries. The bark and leaves of the elder plant are poisonous as well.
Elderflower is used as much for its delightful flavor as for its health benefits; anything containing elderberry is more likely to be a medicinal preparation. You will see elderflower cordials or syrups that are used in desserts and beverages. Although elderberry tea and syrup can have some flavoring benefits, it is often used to provide flavonoids and vitamins.
Because of the difference in flavor, elderflower has more culinary applications when compared to elderberry.
Can you use elderflower in place of elderberry and vice versa?
As with many culinary substitutions, whether you can replace one ingredient with another depends on what you want from them. If you want to replace elderflower with an ingredient that looks similar, elderberry is a poor option. Elderflower and elderberry do not look alike nor do they bring exactly the same qualities to foods.
Elderflower and elderberry do have some of the same chemical compounds, so you may be able to make a substitution if are trying to treat a health problem.
If you want to make a syrup, elderflower may be swapped out for elderberry in some cases. Note that you won’t get the same color and look from each, but you will get sweetness and tartness from both. The difference between syrup and cordial is hotly debated in some quarters but in this context, they are essentially the same things and are primarily just sweet.
You will have to cook elderberries if you want to use them as alternatives to elderflower. Raw elderberries contain toxins that can make you sick.
When should you use elderflower and when should you use elderberry?
Elderflower’s flavor and aroma make it ideal for making a cordial that you will mix with club soda, champagne or lemonade. You can also use it to make fritters, to flavor vinegar and in some liqueurs.
Use elderberry if you want a tart flavor or if you are making jam. You can use elderberry syrup on desserts.