In this Instructable I am going to show you how to make a foam that will change your sensation of taste. Even though it is tasteless in itself it will make everything sour you eat taste really sweet. You can serve it as a cocktail garnish, so that the cocktail changes its taste while you drink it or for example as a dip with lemon and grapefruit slices.

Step 1: Stuff You Need

Tools

• Mortar and pestle
• Scale
• Measuring cup
• Milk frother
• Glasses

Chemicals (for two servings)

• 1.8 g of methyl cellulose (you can get it in an apothecary or on amazon.com)
• 0.5 g of xanthan gum (as well in an apothecary or amazon.com)
• 1 miracle berry tablet (e.g. here: http://www.miracleberrypill.org/). I tried a different brand as well, but this one worked better.

If you are not interested in the Chemistry just skip the next step and go right to the recipe.

Step 2: The Chemicals

Miraculin (wiki)	The effect the protein has on the human sensation of taste has been known for quite some time, but it took till November of 2011 to find out exactly why. Researchers led by Keiko Abe of the University of Tokyo found out that the receptor activation on the tongue under the influence of miraculin is pH dependent. It occurrs every time an acid solution is applied. If you are interested in finding out more about it, take a look at this paper. Growing a miracle berry tree is tricky, because it needs very specific conditions. Depending on where you live you might be able to get your hands on fresh miracle berries, but I'm going to concentrate on miracle berry tablets, because you can get them everywhere.
Methyl cellulose (E461) (wiki)	Methyl cellulose is one of the most frequently used hydrocolloids in the food industry. It is commonly used as an extremely efficient thicker. It has a variety of application and can for example be used to reduce the fat in battered food by making the pre frying step unnecessary (source). Btw. did you know that the slime in the ghostbuster movie is made with methyl cellulose? Methyl cellulose is hard to disperse in cold water (it forms lumps, as shown in the glass on the left) and doesn't dissolve to well in hot water (glass on the right). So the trick is to disperse it in hot water first and then let it cool down (e.g. in the fridge) for some time, so that it can dissolve (glass in the middle).
Xanthan gum (E151) (wiki)	Just like methyl cellulose xanthan gum changes the rheology (flow) of a solution, by thickening it. You can find it for example in ketchup, lotions or toothpaste. In this recipe it helps stabilizing the foam.

If you are interested in the formation and properties of foams and molecular gastronomy in general, check out this really good script from the Wageningen University.

Step 3: Recipie

Solve 1.8 gram of methyl cellulose in 50 ml of warm water (it's more than what you need, but makes dispersing it easier). Put it in the fridge for at least two hours, until the solution is clear, as shown in the previous step.

Pulverise a miracle berry tablet and solve it in 30 ml of water (room temperature is fine), stir (with a spoon) until it is solved fairly well. Then add 0.5 gram of xanthan gum and stir again. Add 5 ml of your methyl cellulose solution and use the milk frother to make an nice and even foam (use it for at least a minute).

Congrats, you are done now get creative!

It will take about one hour for your sensation of taste to go back to normal. If you want the effect to take place fast, you should use a thin, high glass.

Step 4: Cocktails

The foam is a great addition to any sour cocktail (just leave out the sugar syrup for the full effect). Here are two recipes, you can try out:

Mai Tai

2oz rum
1/2 oz orange curacao
1/4 oz Orgeat syrup
the juice of one small lime (about 3/4 oz)

Simply shake everything with crushed ice. I left the lime slices in the glass, to add some extra sourness.

Blue Magarita

2 ounces Tequila
1 ounces Triple Sec
1 ounces freshly-squeezed lime juice
1 ounces blue curacao

Fill a cocktail shaker halfway with ice and add the tequila, Triple Sec, lime juice, blue curacao, and sugar. Shake for about 30 seconds.

Remember to drink responsibly, the foam will make the cocktail taste dangerously amazing. The recipe will work just as well with alcohol free cocktails.

Btw. you can dye the foam and add a taste to it. If you use vitamin B2 powder it will glow under UV light!