Hot and Iced Tea
Specialty Equipment: water bath
Specialty Ingredients: gellan F, sodium citrate, calcium chloride, malic acid
Dish as in The Fat Duck:
I’ve had the prepared tea in the fridge for two days now. I’d like to drink it and give it others, but I have absolutely no idea how I’m gonna make a divider for a small shot glass or where to buy a ready-made setup. This post contains the photos of what has to be done for the recipe minus the you know what shot. If anyone has an idea where to buy a glass with a removable divider or make something at home please let me know.
As for the trick of the hot and cold side of the drink, the actual tea is a very thin fluid gel made with gellan F. For it to work you need water with a calcium content between 100 and 400 parts per million. In the salmon dish there was also a mentioning of the calcium level of water. At that point I didn’t really look into it, but for this recipe you need an exact number, so I did a little bit of research. Tap water is often ‘hard water’: water with a high calcium level. The disadvantage of this type of water is the reaction to certain ingredients. The famous spherification technique of El Bulli is an example where tap water will not give satisfactory results.
Over here the bottles don’t mention the parts per million (ppm), but the mg/L or milligram per liter. Luckily you can, under normal circumstances, interchange these values. I thought I would find bottles with a too high calcium content, but the opposite was true. I could only find one bottle in my local supermarket in the range required. It just made it with 102mg/L.
With the water sorted out I added tea to it and let it soak for one hour. The water is not heated, you just have to let it sit in the cold water. After the soaking it has to be passed through a coffee filter.
For the next part a very sensitive scale is ideal, if not essential. My scale ‘only’ displays the weight with 0,1g intervals. What I did was (for this to make sense the actual recipe comes in handy) combine the two A parts, so I had the combined weight of the white powders to work with.
After boiling the tea with gellan F, sugar and sodium citrate I divided it in half and mixed the two parts with their individual parts B. Makes sense?
Anyway, you end up with a bowl of tea for the cold side and one for the hot side. In the 36 hours after making the tea it will slowly solidify, which, according to the book, can be resolved by pushing it through a very fine sieve. I pushed it through the finest I have, which is in my eyes pretty goddamn fine, but I ended up with something in between a solid and a fluid. How fine are the sieves out there?
My solution was blasting a hand-held blender through the mix, the same way the other fluid gels in the book are made. Unfortunately the result is an aerated tea, which is very stubborn in the release of the newly acquired air bubbles due to the gellan. I think putting it in the fridge won’t solve the air bubbles problem, so if you’re gonna make this recipe you might not wanna use a hand-held blender.
I once read a piece on the removal of air bubbles in a liquid qith a vacuum machine, so I could mine to remove the air. You pull a vacuum, which makes the liquid bubble up, and release it, so it sucks all the air out and blows the bubbles to smithereens.
Well, that’s it for now. Anyone any ideas on a ‘divider setup’?