Recipe: Subtly Strawberry Agar Jellies

I’ve been making agar jellies for a few years, since agar is a good vegetarian substitute for gelatine, and also because it’s fun to feed scientists agar, because they either love it or get really appalled by the idea.  (Agar gels are used for a variety of purposes in the lab, none of which are edible)

The one problem I’ve found with agar jellies, however, is that they tend to be very, very sweet. Yes, they are confectionery, but I have limits when it comes to how sweet I like my confections to be.  Nobody else seems to complain about this, but it has kept me from going all out with agar. 

Anyway, while I was sick last week I had this brainwave – I could make all sorts of weird and wonderful agar jellies and package them in petri dishes to sell, because who wouldn’t want agar jellies in petri dishes, really?  (Yes, I’ll be making and selling confectionery again this year – I’m just waiting for this cold to wear off, but expect news on this front within the next few days) And then I remembered that I had this bottle of strawberry vinegar from Wild Dog Organics (aka the potato and garlic and strawberry guy at the market), and thought, well, that should cut the sweetness…

It does.  My first batch is, I think, a little light in flavour, so I’ve upped the quantity of vinegar for this recipe (there’s nothing wrong with the batch I made, but who wants subtlety in an agar jelly, really?).  Don’t be put off by the extreme sharpness of the mixture when you first add the vinegar – it mellows a lot as it sets.

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200 g water
7 g agar agar powder
300 g white sugar
175 g glucose syrup
10 g citric acid solution (this is 5 g citric acid dissolved in 5 g hot water.  Which is very, very niggly and silly to make.  I usually make up a big batch of citric acid solution and then use it for multiple batches of sweets)
160 ml really good strawberry vinegar (you need one which is quite sharp, but also very strawberryish rather than primarily vinegary)
caster sugar, for dredging

Now what will you do with it?

I’m so glad you asked…

NB – I will try to add illustrations to this down the track.  Unfortunately, I was having thermometer issues yesterday, and thus forgot to photograph things as I went…

Put the water in a saucepan that is larger than you think you will need.  Sprinkle over the agar agar powder, and leave to soak for about 20 minutes.

While that’s happening, weigh out your other ingredients, and line a 22 cm square tin with baking paper.

Bring the agar and water to the boil, and simmer gently for 2 or 3 minutes until fairly clear.  Add the sugar and stir it in well.  Now raise the heat, and boil the sugar and agar mixture without stirring until it reaches 105°C (225°F, or 378.15 Kelvin, since this is practically a science experiment and we might as well be precise).

When the mixture reaches 105°C, turn off the heat, take the saucepan off the stove (especially if it’s electric and holds heat), and stir in the glucose syrup with a spatula until well dispersed.  Now we get even more sciencey, because we have to wait for the syrup to cool to 65°C (338.15 Kelvin) before we add the citric acid and the vinegar.  The reason for this is that agar doesn’t like acid and won’t set if you add acidic things when it’s still hot.

Add the citric acid and vinegar to your goopy agar mixture and pour into the prepared tin.  Leave to set for at least 4 hours, and overnight is better, because it will dry out on top, and this is a good thing.

When the agar is set, use the paper to lift it out of the tin, and sprinkle it with caster sugar.  Put the rest of the caster sugar in a shallow bowl.  Use a knife to cut the agar into squares, or use little cookie cutters if you want to do other shapes.

Drop the agar jellies into the sugar a few at a time, and toss them to coat – you need the sugar to cover all the surface, or they will stick together like you wouldn’t believe.

Store in an airtight container – they will keep for several weeks – or put in a petri dish and serve to the scientists you love.


In terms of dietary requirements, these are pretty much good for everyone except for those going for low-GI food, and confectionery is never going to be low-GI.  They are not going to be low fructose, either, since I’m pretty sure corn-derived glucose syrup is a very bad thing in that department.  But these jellies are vegan and gluten free, and nut-free too, unless you count the nuttiness inherent in making agar jellies and putting them in a petri dish.

In terms of flavour, the sky’s your limit.  The really simple options involve food colouring and flavourings of your choice – I’ve used lemon, lime and tangerine oil, and raspberry, mango, passionfruit, and all sorts of other fruit flavours.  Sometimes I add things like tequila or kirsch or rosewater, and that’s nice, too.  Don’t try peppermint or lavender, though – the flavours clash with the agar in a way that is impressively disgusting.  Do be bold with your flavours and colours, though – insipid jellies are no fun.

If you want to go for natural flavours, this is a bit more difficult, because you need something intense enough to provide flavour in a small enough quantity that the agar jelly can still hold it.  I did quite well with a small tin of cherries in syrup (I laced those jellies with kirsch, too), making about half a cup of thin puree (about the consistency of good, pulpy orange juice).  I found this a little subtle, though, and would probably go with 2/3 of a cup next time.

But seriously, if there was ever a recipe to experiment with, this is it.  It’s science!


This time last year…

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2 comments for “Recipe: Subtly Strawberry Agar Jellies

  1. Iestyn
    December 4, 2012 at 11:10 pm

    The agars in petri dishes sound good. You will mention them here when you a going to start making them?
    But I agree, making them when they would be a potential culturing medium may be less good.

    • Catherine
      December 4, 2012 at 11:26 pm

      I’m playing with flavours right now (blue curaçao agars are magnificently evil), and am hoping to make announcements tomorrow…

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