A small glass of tea made with fluid gels. An interesting effect of gels is that when you shear them into small pieces they want to hold back into a gel structure but at the same time they take on a delicate fluid like state. This recipe takes advantage of this effect by pushing this effect to its limit: when it is at rest the two gels are independent and held up against each other with no barrier in the glass. They are strong enough that lifting the glass will not ruin the effect. However, tilting the glass will and they will flow like a liquid.
Additionally this is a vegan recipe as the gel is based on gellan, a gelling agent derived from sphingomonas elodea, a bacteria derived from lily pond water.
One side dyed in the picture to show the effect but here is another picture of another preparation:
This is 2 gels in the same glass held against each other. Think of the 
The layers in that stay separated. This follows the same concept. But in the tea glass instead of using colors to differentiate the layers the layers are differentiated by temperature.
This results in a small glass of tea where you have both hot tea and iced tea. When you drink it both sensations hit your tongue and mouth at the same time. It’s quite confusing and very interesting
This recipe was created by chris young, who was working for Heston blumenthal at the fat duck.
It is labor intensive and takes some effort but if you want to surprise your guests this 100% will do it.
Hot and iced tea:
Tea infusion:
1.8kg low calcium water: the water should have between 100-400 ppm calcium. Too much and the gel will be lumpy. Too little and it will not set. I use Evian, which is about 80ppm, and add 36mg calcium chloride. You will use calcium chloride later so this isn’t a waste. You don’t need to measure super precisely because this just brings you up to the lower limit of 100ppm for the 1.8kg (however you may want to make much less)
40g tea
Cold infuse the tea in the water - this part is easy. Put the tea leaves in the water and wait. Infuse for at least one hour but not too long. Taste and make sure bitter notes aren’t infusing. 1 hour is often enough.
Strain the mixture. - strain it through a fine sieve lined with a coffee filter. You want it super clear.
Now comes the more difficult part
Hot tea
Part A:
860g tea infusion
80g ultrafine sugar (caster, superfine, bakers sugar)
0.6g gellan F
0.6g sodium citrate
Part b:
0.25g calcium chloride
1g malic acid
5g tea infusion
Prepare ice bath
Bring tea infusion to a simmer. Dry blend part A. Whisk in until dissolved. Mix part B. Once part A is simmering remove from heat, add part b, whisk in, place over ice bath, continue whisking as long as you can, ideally until cool. If you have an automated stirrer that’s the best.
Refrigerate 24 hours then pass through a very fine sieve (I use a 250um lab sieve) then bottle in a squirt bottle (like a condiment bottle).
Cold tea:
Part A:
860g tea infusion
80g ultrafine sugar (caster, superfine, bakers sugar)
0.6g gellan F
0.6g sodium citrate
Part b:
0.25g calcium chloride
3.5g malic acid
5g tea infusion
Prepare ice bath
Do the same exact preparation.
To serve:
Prepare the hot tea: you can either put it in a water bath if you have a sous vide at 162F, or you can microwave it until it’s hot enough, or you can put it in simmering water, etc. the first is the easiest but obviously you need the equipment. The microwave works in a pinch, just shake it up, taste test, go in small increments to make sure you’re not serving lava.
For the glass you need a divider. I use aluminum foil formed to the glass. This doesn’t give the cleanest line as shown in the dyed preparation. In the hot/cold one it doesn’t really matter. In chris youngs video where he does this with coffee he does reveal that he simply made a divider with more gellan to fit the glass. Simple. He doesn’t reveal the recipe though, nor the adaptations to make it work with coffee (there’s also a mulled wine version they served at least once at the fat duck). Youtubers always assume their audience is dumb or maybe he needs hestons permission to release the recipe, I dunno.
Once you have the hot heated up and the divider you’re ready to go. There’s a technique to this but it’s not terribly hard. Basically pour each side evenly then pull the divider out smoothly and as straight up as possible. Try to make the divider as thin as possible. From here serve as quickly as possible because the hot and cold sides will cool and heat each other. Even a few minutes will have you just serving a weird thick glass of tea.
But if you get it right you serve a glass of tea that look almost entirely normal. There is a slight difference in each side, one is slightly darker, but it is very subtle. I specifically use a glass with a handle because if you grab the glass it totally gives it away.
reminds me of hot and cold coffee (EDIT, hah. I didn't read far enough.)
it's a fun gag to pull when you have guests over.
It’s literally this
Chris young invented the technique haha
To be fair, while certainly impressive as a culinary product, Chris Young did not "invent the technique" inherent in this process — he adapted it to a commercial foodstuff. 🤌🏼 One can say that Edison invented the lightbulb (FYI, he stole it), but claiming he invented illumination is ridiculous. 😅
Fair point. The reason I used the phrase “invented the technique” is not to imply that he invented fluid gels (that was Norton and Campbell) but to imply he invented this recipe, which refined the idea of fluid gels (relatively shortly after their discovery in the early to mid 90s) to manage viscosity to the point that 2 opposing gels could be held in a cup vertically.
That said semantics are important so good point
I appreciate the maturity in your response, so I say this with respect: fluid gels as a foodstuff may've been discovered within that timeframe, but have been around for quite a while longer than that. I'm all for sharing and inspiring others with the wonders of clever gastro adaptations, so let's try to keep the phrasing accurate rather than risking it being inadvertently cheapened by hyperbole. 😅🙇🏼♂️
(source: my family has worked in elastomers, etc. before the 90s, and I grew up experimenting with them before spending 25+ years in commercial kitchens across a number of countries.)
Can you reference the history?
Not doubting, just wondering, and not finding much online.
My knowledge here is that fluid gels are credited to Norton and Campbell out of Leeds university. Not necessarily for culinary applications but just the concept as a whole, largely in part because gellan was new at the time, and their work was more geared towards pharmaceuticals and cosmetics than culinary applications. It wasn’t until people like Ferran Adria and Heston blumenthal (and their development chefs like chris young) read their papers that it reached the culinary world and became a wildly overused technique
My understanding is that prior to their work “A molecular view of the gelation of agarose” in 1999 there aren’t really any papers describing fluid gels at all and their work leading up to said paper was the hallmark here. Prior to this there was gels like lbg+xanthan, which can be made a fluid gel, but with far more effort and generally will be a thixotropic gel
The way it may have been written is not as upfront as scientific text is nowadays. Gelatin was used in ancient Egypt and agar (rather than agarose) was reportedly used as far back as the 1600s including for food.
https://en.m.wikipedia.org/wiki/Agar https://thecookingfacts.com/how-was-gelatin-invented/
I would also mention jams and jellies are in a similar fashion and the first known recipe for jam was written in the 4th century AD and it probably existed before then.
Thank you. We only do each other and the culinary community a disservice by leaping over the entirety of history that led the individuals above to the discoveries and products we know today.
I'd also like to add that "fluid gels" are a state of matter, not unlike "plastic", and clarity of use-case, etc. in declarative statements regarding invention/discovery is helpful, if not standard, while showing a mutual respect for one's audience and peers.
I mean, I didn't see your link to the video lower down, so, it was one of those, "AHAH!" and then... I finished reading and was like... "Ooops". I can be like that some times, lol
still, it really is a fun gag, and not particularly hard to pull off. For making dividers, I'd suggest getting some type of PET sheeting- unless you're rocking a giant cup, you can use the plastic containers with berries and fruits from the store. It's reasonably durable, but like, also dirt cheap, so.
My superpower is wall of text, no worries. And Chris young is brilliant so making his channel more obvious is only a good thing (though I wish he would do more novel stuff instead of rehashing old fat duck and chefsteps stuff to have an excuse to plug his new thermometer company but I digress)
The pet sheeting is an interesting idea. It’s a similar issue to the gellan dividers chris uses - I often forget about the dividers until the last minute. So then aluminum foil to the rescue, haha
Also fwiw I would not suggest serving this in a big cup. The scale may not be clear bc of the image but this cup is a bit bigger than a shot glass. The gel modifies the texture of the tea and makes it thicker by a bit, kind of like when you use those thickening agents for people with dysphagia but not as severely (same principle). With a large glass you might start to notice the odd texture a bit more, whereas with a small glass like this it’s mainly that you’re so overwhelmed by the differing temperatures occurring at the same time that the texture is secondary. You notice it but not as much.
Told you wall of text is my superpower
Yup. the best part about using the PET from left over PET containers is that it's already food safe. you could, if you really wanted to, buy some sheets of amazon, but why bother.
also, for the large cup things... there are other things where this trick is useful... like... making pudding cups... :P Most berry containers will have enough of a flat spot you can cut out for a decent sized cup. (especially if you shop at costco or whatever wholesale club, lol.)