Drawing on over 40 years’ experience developing and manufacturing breath alcohol sensors and adapted from them in two years of product development, the AlcoKing brings quick and accurate alcohol analysis within the reach of the winemaker.
The apparatus is configured around two wine samples. In the left hand flask, 100 ml of wine of unknown alcohol content is placed. In the right, 100 ml of a similar wine type of known alcohol content.
The system is allowed to equilibrate for at least 30 minutes. The known value is entered into the system and the start button is pressed.
First, the system calibrates from the known wine. Next, two tests are run from the unknown sample.
Finally a calibration check is run.
The cycle time is around three minutes. The pairs of results are averaged and the unknown alcohol quantity calculated and displayed.
Results are currently being calculated by two methods labelled I and P. If the values within or between the pairs are deemed too dissimilar, the system will reject the test and run another cycle.
The I results have seemed to give marginally better results. Here is a set of repeat tests in which the same wine has been placed in both flasks and the calibration set to 14.0%
For best accuracy a number of additional conditions must be met.
- Flasks must be clean and dry before being charged with the wine samples.
- The temperature of the liquids in both flasks must be equal. It doesn’t matter too much what it is, but if it is too low the operation will be very slow and as alcohol vapour pressures will be low, less accurate. If too high the vapour concentration may exceed the scope of the amplifier gain setting resulting in inaccurate results. Normal room temperatures 18—25C are ideal. Store the wines to be used and the test apparatus together overnight in the room in which the tests are to be performed. Then do not heat or cool the room.
- Condensation in the flasks must be avoided, so care must be taken to ensure that the wine samples do not cool once placed in the flasks.
- The volume of wine does not have to be precisely 100ml but it is very important that the air feed tube reaches down near to the liquid surface while not touching it.
- If repeat tests are required, the wine samples need time to replace the alcohol vapour consumed during each test: ten minutes seems to be sufficient
The current device is a pre-production concept tester. For ultimate sale it will need to be redesigned into an acceptable package.
Here is a demonstration video (you will need a VPN if based in China). The same 14.0% wine is placed in both flasks so we are looking for results of 14.0 +/-0.1.
Dr. Walter King
13 July 2021