How to make the Real thing
You need to get the following ingridients:
Brew Store
Maltodextrin - Comes in many packages or bulk. Ranges from $2-5 a pound. Get this cheap as it is the main ingridient!
Citric Acid
Calcium Carbonate
Grocery Store (QFC)
Fructose - Sold in bulk at QFC, get around 2 lbs, it'll last a long time.
Pectin
Sea Salt - Also found in bulk, you don't need much.
Flavor Extract
Gin (optional for those using non-alcohol based flavor extracts)
To package the GU efficiently, buy Collagen tubes from REI ($2 for a two pack). These seem to be the best way to carry GU into the mountains and in jersey pockets. The following proportions will make one Collagen tube perfectly:
Suppliment Store:
Branched chain amino acids (all three): These are SO important and pretty expensive. Grind them up in a mortar and pestle.
200 mL - Maltodextrin
50 mL - Fructose
100 mL - Water
Carefully measure out the above ingredients, and mix them togeather lightly. Bring the water to steaming hot and slowly wisk in the maltodextrin/fructose mix. Once this is done, mix in a "pinch" of Citric acid, calcium carbonate, sea salt, and pectin. Wisk on med heat until all the lumps are gone. Now you are ready to add your flavor of choice. Almond extract is a staple flavor, but one can get more creative! Make sure that you add some gin if you are not using an alcohol based extract less your GU have a nasty after taste!
The proportions I have found to work have been producing "stable" liquidy GU. Even slight variations in the ratio of maltodextrin to water cause major differences in the consistency of the GU. A little too much water and your have a clear sugary liquid, not enough and you'll have GU-chew! Below I have grabbed the ingredients list for authentic GU off thier website. I have chosen to leave out some of the harder to find ingredients that they use like amino acids, who knows wether they make a difference. Read the marketing and come to your own conclusion!
I started using this recipe for mountaineering. It works very well on my 24 hour climbing marathons. One other things that really helps is chocolate covered espresso beans. Caffine releases fatty acids into your bloodstream with offers 9 kcal of energy/g as compared to 4 kcal from protien and carbs (there is a little more to this story, but I won't bore you with the biochemisty.)
I hope this helps,
Doug