Tips and traps of submitting wine samples for testing
Introduction
Unlike many winery laboratories, a commercial wine lab, particularly a NATA accredited one like ours, runs under a very strict quality system. To achieve accurate results and fast turnaround times for all samples, a regimented system must be in place.
Our four laboratories (NSW, TAS, VIC and WA) do testing for the majority of wineries in Australia – well over 1000 wineries, so a logical and systematic approach is required to ensure customers’ needs are met.
With the busy vintage period almost upon us, it’s a good time to remember that even minor hiccups that occur when sending your samples can disrupt the work flow in the laboratory and lead to delays in sending results to you.
In our laboratory we try very hard to ensure customers’ needs are met in a timely manner. We measure the turnaround time (TAT) at all our labs for each sample and usually exceed our targets of 90% of results out the day after samples are received – last month our four labs achieved TATs of 98%, 97%, 99% and 96% respectively. So obviously we don’t have many clients who cause delays.
However we do get some issues that have the potential to slow us down so here we discuss how you can assist your contract lab to get your results to you quickly and accurately.
Samples
It might sound obvious, but the most critical aspect is to send the correct sample in the correct condition. Compared to other types of samples, wine is pretty easy, at least if it’s not fermenting. Some water samples, for instance, need to be tested within 6 hours of being taken due to their inherent instability. Wine is a very stable matrix as long as care is shown in taking the sample and filling the sample bottle correctly. If a sample is not taken correctly, delays may ensue while the lab waits for a replacement sample.
For example, the most common preservative in wine is sulfur dioxide. It is well known that it is very reactive and hence unstable. Any wine sent for sulfur dioxide testing needs to be sent in a full bottle, with little or no ullage, although this isn’t the case for all samples we receive.
TIP:
if getting sulfur dioxide tested make sure you send full bottles!
TRAP:
Our ISO-accredited wine labs are not responsible for taking the samples, and in fact under NATA rules we must have a disclaimer to this effect on each test report
Another sampling example: we offer free postage of samples to our labs as part of our EasyTest Sample System. We have had numerous complaints from Australia Post over the years (who incidentally offer a great Australia-wide delivery service) about broken glass containers in the post. We provide EasyTest plastic bottle packs free to all our clients so that they don’t have to use glass for small samples. During vintage, sending fermenting musts in glass can actually be very dangerous. Our sample-receipt team wear safety glasses due to previous incidents we have encountered of exploding glass bottles.
TIP:
don’t send fermenting samples in glass bottles!
Sample labels
Figure 1 shows a far too common situation. They are quite possibly great wines, but we have no idea what testing the winemaker wants. Even if you send a note in the parcel, the situation can occur where the parcel gets damaged in transit, the note disappears and we get bottles without any labels. We have also had instances where not only are the bottles not labelled with who sent the wine, but the carton isn’t either. Some of our staff love this detective game – checking out postmarks on parcels, getting clues from logos on bottle capsules, looking for embossing on bottles – trying to at least find out which winery sent the samples. Whilst mildly entertaining, it’s not the best way for the client to get fast results.
Sometimes we have had to put unlabelled, unbranded bottles from unlabelled parcels aside and simply wait for the owner to ring or email and find out why they haven’t got results. Fortunately this isn’t a common occurrence, but it still happens more than it should.
Figure 1: some recent samples sent for testing
TIP:
make sure you apply a label to each sample container and fill in the label fully!
TIP:
put your name and address on the parcel so we can follow up and find out what testing is needed if samples are not labelled or the labels get damaged in transit
Volumes of samples
Each test requires a certain volume of wine so that the test can be done correctly. Part of our ISO 17025 accreditation insists we do multiple tests on a certain number of wines so that our statistics demonstrate consistency in our testing. We advise the volume needed on our website and in other communications. If enough wine isn’t sent, again delays can occur waiting for fresh samples to ensure accuracy.
I had the pleasure to catch up with an old winemaking buddy recently at one of our reception counters, only to inform him that unfortunately he didn’t bring in enough sample for the tests he wanted done. He was under the impression that since he last did lab testing as a rookie (decades ago and before CSI shows on TV), only a few drops of the sample were needed to do a wide range of tests. If you want accurate results this is still not the case.
TIP:
check how much wine is needed for each test (this info is on our website), add up the total and send the required amount. If in doubt give us a call.
Other issues
After asking all our lab team members for their feedback on these matters there were a few more issues they raised that are worth mentioning.
Asking for excess wine back after the testing is complete:
I’m not quite sure what to say about this one…we know your wine can be dear to your heart, but once a sample of wine has been exposed to a busy lab full of Dangerous Goods, even if there is some remaining in the opened bottle, it’s probably best just to let it go…
TIP:
Leaking sample containers: make sure you do up the lid on each sample bottle tightly
TIP:
Unclean sample containers: get free clean sample bottles from us to avoid contamination.
Vintessential Laboratories are dedicated to helping our customers discover production problems early, understand them, and then fix them. At our laboratories around Australia we test hundreds of samples every week, so there’s hardly a problem we haven’t seen. Our articles bring you some of the recent problems that have been sent to us and explain how, working with our clients, we managed to solve them. Greg Howell founded Vintessential Laboratories in 1995. More articles on related topics are available on the Vintessential website: www.vintessential.com.au/resources/articles/
