Enzymatic Reader FAQs

How are alcohol-free and non-alcoholic beers defined?

The definition strongly depends on local laws.

0.0 % beer: This usually means the beer is intended to contain 0.0 % v/v or only trace alcohol close to zero. Most commonly, it must be possible to round the ethanol content to 0.0 % v/v, so the highest allowed alcohol level is 0.04 % v/v. Other countries require levels below that (e.g. 0.02 % v/v) for labelling products as “0.0%”.

Non-alcoholic beer: Often used similarly to alcohol-free beer, especially for beers with < 0.5 % v/v. At the EU level, there is no fully harmonized legal definition for low or no-alcohol beer; however, EU customs nomenclature recognizes “non-alcoholic beer” as beer with alcohol strength below 0.5 % v/v.

Alcohol-free: “Alcohol-free” does not always mean 0.00 % alcohol. It can still contain small residual alcohol up to the legal or market limit of up to a few % v/v.

Low-alcohol beer: Beer with reduced alcohol content, but typically above the alcohol-free/non-alcoholic threshold. The exact limit depends on country-specific rules.

Table 1. Typical definitions of alcohol levels (dependent on local legislation).

Term	Typical ABV meaning	Practical interpretation
0.0 or zero alcohol	< 0.02 or < 0.04	Stricter claim, closest to no alcohol
Non-alcoholic	≤ 0.5 % v/v	Often equivalent to alcohol-free
Alcohol-free	≤ 0.5 % v/v	Very low alcohol, not necessarily 0.00
Low-alcohol	> 0.5 % v/v	Reduced alcohol, but not alcohol-free

When should I use the Enzymatic Reader?

The Enzymatic Reader is designed for selective verification of ultra-low alcohol concentrations in 0.0 % beer below 0.05 % v/v. It is particularly suitable for final product release testing and for samples close to legal or internal specification limits.

When should I use the Alcolyzer?

The Alcolyzer is ideal for routine alcohol measurement across a broad concentration range, from non-alcoholic to alcoholic beers. It is especially well suited for fast, high-throughput QC measurements during the production of all beer types.

Why combine the Enzymatic Reader with the Alcolyzer?

The two technologies complement each other:

The Enzymatic Reader provides highly selective reference measurements in the ultra-low alcohol range required for 0.0% beer verification
The Alcolyzer enables measurement over the whole alcohol range. For 0.0% products, a one-time reference check is recommended

Together, they support efficient workflows for breweries producing both alcoholic and non-alcoholic beers.

Can the Enzymatic Reader be used as a reference for the Alcolyzer?

Yes. Breweries can use the Enzymatic Reader for selective low-range verification of 0.0% beer and the Alcolyzer for routine quality control measurements afterward.

Can the Enzymatic Reader replace the Alcolyzer for all non-alcoholic beers?

No. The Enzymatic Reader is optimized specifically for ultra-low alcohol verification below 0.05 % v/v. For higher levels of alcohol, the Alcolyzer is required. For routine measurement of “regular” beverages, the Alcolyzer is often the more efficient solution for daily QC workflows.

Why not use the Enzymatic Reader for all alcohol measurements?

The Enzymatic Reader is designed for highly selective low-level verification. For routine high-throughput alcohol analysis across broader concentration ranges, other measurement technologies such as the Alcolyzer may offer workflow and cost advantages.

Why not use the Alcolyzer alone for all 0.0 % beer applications?

Some beverage matrices may contain components that can influence non-selective measurement methods at extremely low alcohol concentrations. In addition, measurement of very low alcohol levels requires proper cleaning and calibration of the device. The Enzymatic Reader adds selective verification capability for applications where maximum confidence in ultra-low alcohol determination is required.

How do I ensure the alcohol content is below a threshold with statistical significance?

A calculation is included in the measurement systems. Two terms are important:

Compliance limit: The check limit is the maximum measured value that still confirms the sample is below the target limit after uncertainty is considered
Control limit: The control limit is the maximum measured value that still confirms the sample is below the target limit after uncertainty is considered

More information can be found on the Anton Paar Wiki page.

How does a measurement using the Enzymatic Reader work?

The measurement principle is based on an enzymatic reaction in which alcohol dehydrogenase (ADH) converts ethanol into acetaldehyde. The oxidation of ethanol is detected on the sensor strip by measuring the resulting electrical current, which is proportional to the ethanol concentration in the sample.
A workflow guides users through sample preparation and measurement while the other modules are measuring. For the measurement, the sample has to be degassed, mixed with buffer (1+4) and applied with a spoon.
If using an Alcolyzer module, this can be cross-referenced with the Enzymatic Reader. If required, an offset can be determined to fine-tune the Alcolyzer result depending on the sample matrix.

How do the Enzymatic Reader data compare to reference methods?

The data correlate well if they are analyzed carefully according to, e.g., MEBAK 9.3.1 (enzymatic method) or 9.3.2 (gas chromatography), generally with an accuracy of 16 % of the measured value or 0.0025 % v/v (whichever is greater).
Significant differences can be caused by sample preparation and handling, as well as the analytical methods in place. It is crucial that all analyses are performed in parallel, as batch fluctuation, ethanol evaporation, and spontaneous fermentation upon contact of samples with air can affect the ethanol content of the sample.

How often is calibration of the Enzymatic Reader required?

The reader measures only current and voltage and therefore does not require calibration, provided its components are free from corrosion or damage. The sensors are single-use and include adjustment data encoded in a QR code. If they arrive undamaged and are stored according to specification, no further calibration is required.

Two checks should be conducted:

The Enzymatic Reader check with a supplied testing device to validate the functionality of the reader – required only upon installation and in case corrosion of internal parts is suspected.
The Enzymatic Reader 0.05 % v/v check to validate a sensor batch performance is recommended upon receiving a new batch. A pre-mixed standard of 0.05 % v/v with buffer is supplied with the sensors.

How does temperature influence the Enzymatic Reader measurement?

Temperatures below 18 °C can deactivate the enzyme and lead to low values, especially if the strip, buffer, or sample is too cold. The buffer should therefore be stored on the bench before use. Above 24 °C, values may increase slightly with higher temperature – the higher the alcohol content, the stronger the effect.

How do bubbles and filling affect measurement with the Enzymatic Reader?

A bubble on the central electrode can cause values to be too low, while a side bubble likely has little or no effect. Insufficient filling volume may also influence results, so filling should be done carefully without rushing: turn the spoon by 90°, place it over the lash, and move it upward slowly.

Why are measurement timing and sample handling important for measurement with the Enzymatic Reader?

Samples should be prepared directly before measurement, as delays can affect results. Samples stored for a longer period may show reduced ethanol content due to evaporation, but also spontaneous fermentation can happen upon contact with air, causing the ethanol levels to rise. In addition, high ethanol content in the atmosphere can also elevate the alcohol conten of samples when, e.g., stored open next to an opened flask of ethanol.
Fill the sensor only when the guided workflow indicates it as the oxidation of ethanol will start immediately.

How long is the shelf life of the provided enzymatic sensors?

At least six months from date of dispatch when stored at 2 °C to 8 °C. The strips must not be stored at higher temperatures for long durations or outside of the sealed package.