Blackthorn Flower Syrup

We had a good weather day a couple of days ago and I thought “Spring is here!” I love to see the Blossom out, I feel winter has finally been banished. So with Spring on my mind and a spring in my step (sorry, couldn’t resist it) I ventured forth.

I’ve seen lots of blossom on the trees and normally one of the first blossom we see is from the Blackthorn (Prunus spinosa). This year with winter being so mild everything seems to be running ahead of nature’s schedule, because of this I was worried that I’d missed the Blackthorn. When I got out to one of my favourite patches of it I discovered that it was one of the few blossoms NOT out! Now I’m wondering why; does Blackthorn go on daylight hours rather that temperature? Do the others (Wild and Bird Cherries) go on temperature? Answers welcome…

Blackthorn001        Blackthorn flowers

One of the many reasons I feel attracted to the Blackthorn is the smell of the flowers…it subtle, like the delicate flowers themselves. It is light, sweet, with hints of almonds.

I managed to collect about 3 cups worth of Blackthorn flowers. They are quite different from the Bird Cherry blossom that was next to them. The Cherry blossom is almost twice the size and white with a very pale pink hint, while the blackthorn flowers are half the size, and more of a cream colour. The Cherry flowers dangle from stalks like the fruit will later in the year, while the Blackthorn flowers are densely clustered and close to the twigs.

OLYMPUS DIGITAL CAMERABird Cherry on the left, blackthorn’s smaller flowers on the right.

Picking blossom is a time consuming affair. I’m looking for blossom that has plenty of pollen, and not been either wind blasted or all the goodness taken by early insects. I also try to leave blossom for the bees, as they’re hungry this time of year, and I don’t want to take too much from one plant as that will mean that I may get a shortage of Sloes later in the year.


Once I got home I made a slow warm infusion with the blossom. I put the flowers in a pan of water. I should have measured it but working backwards it was probably about 750ml. I brought it up in temperature but didn’t let it reach a simmer. I feel that too harsh a heat brings out too much bitterness in the plant material. I wanted to keep the flavour as light and fresh as possible. I kept the flowers heating in the water for at least 15 mins, probably a bit longer.

The flowers were strained out, the fluid measured – now about 500ml. The general rule of thumb is equal amounts of sugar to liquid, so I added 500g of white granulated sugar to the infusion. I chose plain sugar as I wanted the colour to be as light as possible and the flavour to be as close to the smell of the flowers as possible.

The hard thing for me in syrup making is not to stir! I’m a natural stirrer ( remembering many family arguments, my mother would surely agree!). The danger with stirring is that grains of sugar migrate up the sides of the pot, so that when pouring out your finished syrup, you run the risk of adding the sugar crystals into your new syrup in the container, thus giving the perfect conditions for growing large crystals. This is apparently frowned upon, personally, I think it looks cool.

To prevent any sugar crystals being deposited on the sides of the pot I put the sugar in via a funnel so it  just sat there on the bottom of the pan perfectly behaved. I said ‘pot’ then ‘pan’, is there a difference?

I heated up the liquid till the sugar dissolved then brought the infusion to a boil, reduced to a simmer and kept it at that for about 15 mins, or until it thickens up. I’m sure thermometers are meant to come into it but I’ve never really bothered.

The still hot syrup (so be careful) is then poured via a funnel into a sterilised bottle or flask. You can boil the container for about 15 mins as I did, or put it into the oven at around 120 C for 10-12 mins. Just make sure that your cap or top won’t melt in the oven, they are often best boiled separately. Another word of warning, make sure you let your  sterilised container cool a bit before trying to handle it or pour into it! No burning of hands or melting of plastic funnels, please!


You should end up with a lovely golden and pleasantly almondy smelling and tasting syrup. This can used as a cordial, used over ice cream or pancakes, or added to sorbets, cakes, or hopefully, made into a filling for a spring chocolate! I have plans to make a Blackthorn flower cold infused cream, to make into the ganache and use the syrup as part of the sugar component for a filling for choccies, nom nom nom.

Happy foraging and creating.