I have read all these posts and feel like I have some points to offer.
TO COOK ISOMALT WITH OR WITHOUT WATER - Okay, here is the scoop - You can cook Isomalt both ways and each have their advantages. First, you must understand that 14% of Isomalt in its dry natural form is water soluble. Adding just enough water to make the Isomalt resemble wet sand is exactly enough water to dissolve the 14% while cooking. What do you get when you add water and dissolve all the Isomalt? You get an Isomalt that is less thick and it pours more easily. Cooking with distilled water conditions the isomalt by dissolving parts of it that make it more manageable for pouring and pulling. Think of the water as an inner lubrication that helps the Isomalt move when we pour or pull it.
1. Use distilled water - many parts of the country have what is called hard water. The minerals in tap water can turn brown when exposed to elevated temperatures but because there is so little of these minerals you perceive it as a yellowing effect.
2. Add only enough water so the isomalt looks like wet sand.
3. Use Stainless Steel pots and Stainless Steel utensils for stirring. Do not use a wooden spoon. Foreign materials in the wood leach out into the isomalt which can turn the mixture yellow.
4. Do not use a natural bristle brush to wash down the sides of the pot once isomalt comes to a boil. Use a nylon pastry brush. There are a host of chemicals and conditioning agents in the natural bristles that can turn your isomalt yellow.
5. Stop stirring isomalt water mixture when it comes to a boil.
6. Test your candy thermometer. many of them read inaccurately. Test by bringing water to a boil and inserting thermometer and observe the temperature is shows. It should read 212 degrees F.
7. Cook isomalt to 338 degrees f. Take off heat at about 334 and place bottom of pot in water to stop the cooking process. Allow the pot to stay in water only until the hissing stops. About 5 seconds.
8. Place isomalt in a 265 degree oven and allow to cool for 15 minutes. You will have no bubbles and pure, clear liquid crystal to pour all day.
COOKING ISOMALT WITHOUT WATER - Isomalt will melt if you put it in a pot and apply a medium high heat and stir in a way that scrapes the bottom and brings the melted Isomalt up so unmelted Isomalt falls to the bottom and melts. You are going to think that its not working but keep stirring and eventually you will see that it all melts and becomes a liquid. Once melted, stir occasionally after putting in your thermometer. Okay, so you remember that I told you 14% of the Isomalt is water soluable? Well, because we aren't adding water it never dissolves and if you cook it to 338 degrees like above, you will see little white specs. To get clear Isomalt when not adding water, you have to cook it to a higher temperature of 370 degrees. Don't worry - Isomalt cooked without water is more resistant to yellowing at high temp. so it will still be clear. Also, Non water cooked isomalt never really boils at 370 degrees and it will not look very clear when you reach this temperature. Don't worry - take it off at the correct temperature and place it in a 290 - 300 degree oven and you will see that the cloudiness is just air that comes out if you let it rest in an oven for 15 to 30 minutes.
ADDITIONAL COMMENTS - I have found that if you take properly cooked isomalt with water added and put it right beside isomalt cooked without water, the water cooked isomalt is clearer. Non-water cooked Isomalt is still clear, but not crystal clear like water cooked Isomalt. I have found that non-water cooked Isomalt is more resistant to clouding once the sugar pieces are made. Instead of clouding, it gets sticky but remains clear. Non-water cooked Isomalt is is less resistant to humidity than water cooked Isomalt - I think it is because the 14% of its water soluble content has never been dissolved with water. Even though it is more susceptible to humidity and gets sticky quicker - it retains its shine and resists clouding. Water cooked Isomalt will cloud sooner if exposed to humidity. All Isomalt or cooked sugar will eventually cloud and dull out if left in a humid environment.
I hope this helps everyone and for anyone going to the ICES convention in San Diego - I am giving an Isomalt Demonstration on Thursday where I am going to teach everything you need to know when using Isomalt. I just hope I have enough time to get all the information demonstrated in 1 hour.