Iodine solution for the determination of starch in cooled wort.
Method:
Mix the mash thoroughly
Drop 3-4 drops of juice from the mash onto a white, flat plate
Add 1 drop of iodine to the wort.
Iodine is brown by default. However, if it encounters very long carbon chain carbohydrates (starches), its color immediately turns blue.
If it retains its brownish color when it meets the wort, there is no starch present in the mash, which means that the mash has been completed successfully. We can even mash and start copying. But we can mash further and even increase our output by a few %.
But if the brownish color immediately turns blue, it means that there is still starch in the solution. The lighter the blue color, the more starch and vice versa. If we do the experiment in the first 5 minutes of mashing, we will see a dark, almost black, deep blue color of a blackberry. From this we know that the experiment was done well.
Recommended for both beginners and advanced users, it can be used to eliminate the possibility of half-finished mashing, which can lead to a higher than desired, 'stuck' final fermentation.
Capacity : 30ml
Lifetime : Enough for a lifetime
The video below shows the method and the visual feedback we get:
VIDEO