FAQs
MICROBIOLOGY
What time do I need to get a sample in to Vinquiry Enartis for you to plate it on the same day?
We can usually culture a wine sample the same day if it arrives in time for the receptionist to enter it into the computer database. This means that it needs to be at Vinquiry Enartis no later than 4:30 pm. There may be other circumstances, such as the work load, that would result in plating being delayed. Be sure to tell the receptionist if it is urgent that you get your results as soon as possible.
How soon can I get my microbiology results?
We usually do microscans the same day. A culture plate needs to be incubated anywhere from two to seven days: Saccharomyces yeast colonies and Acetobacter colonies usually appear within two or three days, but Brettanomyces colonies and lactic acid bacteria colonies often take up to a week to appear.
What does some of the microbiological nomenclature mean when I get plating results?
"lawn of colonies": colonies appear close together, like leaves of grass. This is more colonies than "too numerous to count", although sometimes it is difficult to determine where to draw the line.
"confluent growth": colonies are so dense that they have grown together, so that for the most part it is impossible to distinguish individual colonies. In many cases a lawn of colonies, given enough time, will become confluent growth. Molds, and some non-wine Bacillus, will often outgrow the wine yeast and bacteria on the rich media used to culture for these organisms. Confluent growth of these common environmental contaminants may make it impossible to determine the concentration of things that do grow in wine.
What are "non-wine Bacillus" and how did they get into my wine?
There are thousands of species of bacteria that, fortunately, cannot reproduce in wine due to the low pH and high alcohol content. Some species, however, form endospores that are resistant to temperature, alcohol, pH changes, etc. These propagules may survive in wine, germinate and reproduce rapidly on the rich media that is used for microbial plating. They sometimes produce large spreading colonies that can obliterate the colonies of wine bacteria and yeast.
Can you identify the species of yeast (or bacteria)?
At Vinquiry Enartis we can usually identify the genus of wine bacteria. However, we have to send a culture out to a specialty lab on the east coast for a positive identification at the species level. We can also usually differentiate between glucose fermenters and (aerobic) film yeast cultured from wine, but again, for positive identification we have to send the culture to a lab that specializes in such identification.
Can you make a yeast starter culture for me?
We supply yeast cultures on slants, but do not have the facilities to build up liquid cultures of yeast. However, we carry the Williams-Selyem yeast in a concentrated liquid culture suitable for inoculating 200 gallons of must or juice.
What do you do when wine is partially through malolactic fermentation and volatile acidity level is increasing?
Do a microscan to evaluate bacteria population. Is the wine dry? If not, use Lysozyme to inhibit MLF until fermentable sugar is depleted then reinoculate with malolactic bacteria, maintaining optimum temperature around 70°F. Remember to run volatile acid tests to monitor change.
PRODUCTS
Can I keep my yeast (or bacteria) after I open the package? What is the best way to store it?
Active dry yeast should be stored cool in an airtight container. For long-term storage--longer than a year, increase inoculation rate by 15% to compensate for any activity loss. Freeze dried bacteria should be used immediately after opening. Moisture in the air begins the process of rehydration and the bacteria, with no substrate to feed on, will die.
Can I return yeast for credit if I bought too much?
Our policy on all fermentation type products is that we do not accept returns. Once a biological product has left our warehouse we have no control over storage conditions. To ensure the highest level of activity, we do not accept yeast for returns.
What should I do if my brix level doesn't change after adding yeast?
Assuming you have a brix level above 5°, do a microscan and stain for yeast viability. If no bacteria problems are identified in the scan and yeast viability is low, add 2#/1000gal yeast hulls and reinoculate with 2 to 4 #/1000gal yeast. Maintain temperature around 70°F for optimum fermentation rate to minimize the toxic effects of ethanol.
ANALYSIS
How much sample must I send in for a particular analysis?
The amount of sample required varies enormously, depending on the analysis. View the requirements for individual analyses on our Sample Requirements page.
What equipment do I need to start my own winery laboratory?
For the basic wine chemical analysis, plan to run titratable acids, pH, and °Brix. You might want to add SO2 analysis by aeration oxidation or Ripper methents. For °Brix, plan on a refractometer with temperature compensation for juice and vineyard sampling, then a set of hydrometers to monitor fermentation.
How do I treat my fermenting wine to remove the sulfide aromas?
Set up bench trials to determine the effectiveness of a copper addition and the rate needed. Add copper in 2 doses and make sure SO2 levels are maintained post fermentation.
What analytical parameters do you use for wine stability for bottling?
For bottling, determine alcohol, pH and SO2 levels. The glucose/fructose levels should be less than 100mg/100mL for wines that are not sterile-filtered and less than 25mg/100mL especially for red wines. The malic acid levels should be less than 30mg/100ml.
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