Iodine for starch test in wort - 30ml

Iodine for starch test in wort – 30 ml

An iodine test is a simple way to check whether mashing is complete, i.e. whether the starch in the malt has been converted to fermentable sugar. Iodine changes colour when it comes into contact with starch, so you see the result immediately.

How to do the iodine test

1. Take a small wort sample and place it on a light surface, such as a white plate, so the colour change is easy to see.
2. Let the sample cool to room temperature, around 20 °C.
3. Add a few drops of iodine to the sample.
4. If the colour turns blue, black, violet or red, there is still starch left and mashing must continue.
5. No colour change (yellow to amber) means the starch has been converted to fermentable sugar.
6. Discard the sample. It must not go back into the mash.

Technical data

• Contents: 30 ml iodine solution
• Manufacturer: Brouwland

Frequently asked questions about the iodine test

When should I do the iodine test?

Towards the end of the mash. A typical mash lasts about 60 minutes, but the test shows whether the starch has actually been converted.

Why must the sample be cooled?

The colour change is easiest to read when the sample is at room temperature, around 20 °C.

Can I pour the sample back into the mash?

No. The sample with iodine must be discarded. Only take a small sample each time.

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