How To Collect A Sample
For accurate Beverage Analysis results, we need an uncontaminated sample.
Please follow the guidelines below.
Collecting a Beverage sample – General Guide
- All samples should be collected in sterile plastic or glass bottles.
- Make sure the Beverage sample accurately represent the product.
- This may influence the way of extraction Rinse the sample container with the beverage to be analysed – then proceed to fill the container
- Samples must be identified and labelled in detail. Essential information should included:
- sampling date
- sampling time
- origin of sample
- type of sample
- Sample preservation and storage:
- Although recommendations vary, the time between sample collection and analysis should, in general, not exceed 12 hours (24 hours are considered the absolute maximum).
- It is imperative that samples are kept in the dark and that cooling is rapid.
Collecting an uncontaminated sample
In order to take a sample that is representative of the wine and get accurate and meaningful results, all external microbial growth that may potentially contaminate the wine during sample taking needs to be eliminated. External contamination occurs very easily and can be from both wine-tolerant microbes and non-wine microbes, both of which will be in abundance in and around the sample taking area e.g. the valve, barrel thief etc.
- Samples need to be taken in a sterile and aseptic manner as follows:
- Use a sterile sample container and closure (never rinse the sample container with tap water) – Rinse the sample container with the wine to be analysed before filling.
- Tanks: spray a 70% alcohol solution into the valve.
- Allow at least 2 of wine to run out before collecting the sample.
- Barrels: rinse thieves, barrel-stirrers etc with a 70% alcohol solution
- Now rinse all equipment with the wine before collecting the sample
- Be careful not to touch the outside of the barrel with the sampling device.
- Sampling devices should be rinsed with a 70% alcohol solution and then wine in between samples to avoid cross-contamination.
Winery wastewater: Taking representative samples
- Samples should be taken at points that most appropriately represent the water source, discharge point or storage facility e.g. for irrigation water, samples should be taken at the point where the irrigation water starts to flow.
- Sampling frequency:
IPW guidelines recommend the following sampling and analysis schedule:
- Pre-harvest: every two weeks
- Harvest (early, peak and late): weekly
- Post-harvest: every two weeks – Rest of year: every 6-8 weeks Storage of samples:
- Samples for water microbiology tests should preferably be analysed as soon as possible after the sample is drawn. This is because E.coli will start to multiply after 6 hours, and results may be overstated.
- Samples should be kept cold using ice packs and should be stored in the dark