Small Trials Before Making Big Decisions

By: Thomas J. Payette, Winemaking Consultant

scientist smiling enthusiastically

Trials and fining agents, in the wine business, are often riddled with unfamiliar language and terms.  Grams per liter, grams per thousand gallons, pounds per thousand gallons and milligrams per liter roll off most winemaker’s tongues as if the world is in tune.  Let’s review how to make this simpler and to understand.


We should perform trials anytime a question is raised on how to improve or change a wine.  If a wine has a problem – identify the solution in a laboratory first.  Then apply the desired corrective action in the cellar.  Always double check you trial and math before performing in the cellar.


The reason we do trials is to experiment with refinement, improvement and / or correction of a juice or wine.  Always work in small quantities with a wine so one does not create a larger problem, in a tank, in need of potential further corrective action.  These trials can be tasted and tested to see what the results would, or will have been, if the addition was made to the actual tank or vessel of juice/wine.  This eliminates guesswork and unnecessarily “shooting from the hip” in the cellar.


One should do these trails in the laboratory where control, on a small-scale amount of wine, is essential.  The opportunities of what one can discover in the lab are almost endless.  I repeat let’s always make our mistakes on a small scale in the laboratory before stepping into the cellar for any actions that may change the flavor, aroma or chemistry of any juice/wine.  This lab area should be designed for this feature of experimentation. The metric system will be used.  Once this is attempted, one will not step back into some of the complicated aspects or other forms of measurement.  These trials can be used for many things including but not limited to: sugar additions, acid additions, fining agents, concentrates, de-acidification’s etc.

Potential Tools Needed

  • Accurate scales that measure in grams preferably to a tenth of a gram.
  • 3 – 100 milliliter graduated cylinder (plastic preferred).
  • 1 – 50 milliliter graduated cylinder (plastic preferred).
  • 1 – 10 milliliter pipette (Class A volumetric).
  • 2 – 10 milliliter pipettes with graduated markings at each milliliter to the tenth. (Plastic preferred) [ AKA : Serological ™ ].
  • Small glass beakers 250 milliliters plus or minus

Representative sample(s) of each wine to be sampled.

  • Clean wineglasses.
  • Glass watch glasses to cover each glass.
  • Spit cup.
  • Other testing equipment to answer questions at hand.
  • Magnetic Stir plate with stir bars and retriever for the stir bars.
  • Sharpie™ pen or pencil for marking beakers.
  • 95% ethanol to remove Sharpie™ pen marks off glassware.


Start with something simple where results can be easily determined with the wineglass to give the confidence needed to build upon the procedure.  An example of this may be a tartaric addition trial for pH correction and/or palate modification.  Let’s go over one example.

  1. Start with an ample quantity of wine to work with in the lab – perhaps an 800-milliliter representative sample from a wine vessel.
  2. Weigh accurately 1.0 gram of tartaric acid and fully dissolve the acid in approximately 85 milliliters of the base wine with which you are working.
  3. Once dissolved, place the full amount into a 100 milliliter graduated cylinder or as one becomes more experienced you may just make the solution in the 100 milliliter graduated cylinder.
  4. Bring the amount up to volume in the 100 milliliter graduated cylinder up to 100 milliliters mark with additional base wine. [One should be clear they have made a solution of 1.0-gram tartaric acid dissolved into 100 milliliters of wine.]
  5. In a clean graduated cylinder, pipette 10 milliliters of the newly prepared acid stock solution into the cylinder. Bring to the complete 100 milliliters volume mark with the base wine.  This should represent a 1.0 gram per liter tartaric acid addition.
  6. Pipette twenty milliliters from the stock acid solution made in step four into another graduated cylinder and bring to volume at the 100 milliliter mark to represent the next addition level of 2.0 grams per liter tartaric addition.
  7. Continue to add to the number of samples you care to do the trial on in standard logical increments.

Set Up the Tasting Trial

  1. Pour about 50 milliliters or a quantity one desires to smell and taste, of the base wine, into a control glass and place it in the left hand glass in the tasting area. (One should always taste against a control)  Taste Left to right.
  2. Pour the trials to be tasted, made in steps 5,6 and 7 above, in increasing increments in each wineglass progressing from left to right. Mark their contents.
  3. Add to this flight any wines from past vintages you may want to review or any other blind samples from other producers you may care to use as a benchmark. Mark their contents.
  4. Taste and smell each wine several times. Go through the flight and detect what wine may best match or improve the desired style one is trying to achieve.
  5. Select the match and leave the room for 1 to 2 hours.
  6. Return and re-taste to confirm your decision.

Should chemistries play an important role to reviewing certain additions be certain to run a necessary panel of lab test to ascertain the proper numbers are also achieved.  One may need to balance taste, flavor and chemistry to make some tough choices.  Have all the data necessary and available to make those choices.


Once the fear of the metric system is overcome and confidence is achieved, the calculations become very simplistic.  Let’s take the above as the example.  If we dissolve 1.0 gram of tartaric acid into 100 milliliters of wine we now have 0.1 gram of tartaric acid in every 10 milliliters of wine.  From this base if we blend 10.0 milliliters (one-tenth gram of tartaric) into 100 milliliters of fresh wine – this represents the equivalent of one gram per liter.

If we were to have used twenty milliliters that would represent two grams per liter in the small 100-milliliter lab blend.  If we keep track of what we are tasting, or testing, and select the trial we prefer, one can mathematically calculate how much of the given addition is needed in a tank of known quantity of juice or wine.  One can also extrapolate this out to larger volumes in the laboratory should that be desired to work beyond a 100-milliliter sample.

Spicing it up!

Once the first set of trials is mastered one may build on to the next step projecting out what one may want to do with the wine.  This could eventually, and perhaps should, build out to treating large enough samples that one could cold and protein stabilize the wine in the lab, filter to the projected desired micron size and taste with a panel.

Double Checking the Results

From experience, one can get so creative in a lab it can be difficult to trace exactly how one arrived at a certain desired concoction.  Copious notes should be kept and most often one can trace their steps.  When in doubt; however, re-perform the steps with each addition to reestablish and confirm the same results.  This extra time is well worth doing before stepping into the cellar.


Given time and experimentation with this system many blending trials with additions will become easy and systematic.  Trials will often take less than ten minutes to prepare and one may taste at several points during the day or use extra time to perform lab test to confirm desired objectives.

Other Helpful Tips

Keep in mind not to over scrutinize your accuracy in the laboratory.  By this I mean make sure that if we measure something very tightly in the laboratory make sure this action will be able to be duplicated outside the lab.  It is not uncommon, early on, for winemakers to get extremely exact in the lab only to step into the cellar with less exact control over what they had just experimented with.  Food for thought on the practical side!

One can use other base solutes should that be desired.  It does not always have to be wine.

This system can be used for dosage formulation for sparking wines.

If accurate scales may be an issue the winemaker may always start by weighing larger quantities and dissolving into solution then breaking down that solution.  Example:  If a winemaker wants a 1.0 gram per liter solution and the scales are not accurate enough to weight one gram the winemaker may dissolve 10.0 grams into 100 milliliters and then measure out 10 milliliters of that solution and this should roughly equate to one gram.

Make sure all solids are dissolved and dispersed equally into any solution.

One may also be able to blend two trials in 50% to 50% solutions to get an example of a trial in the middle without having to make one up specifically to match the amount desired.

Always remember your palate may become desensitized while tasting and to step away from tasting for an hour or two and then return to taste a potential preference.  You may be shocked you had become used to certain levels because of tasting such extremes.  Desensitized in essence.


Verbal discussion with Mr. Jacques Boissenot, Mr. Jacques Recht, Mr. Chris Johnson and Mr. Joachim Hollerith.

  Dedicated to Chris Johnson: A long-time colleague and friend who worked with me to develop this system together many years ago.  Chris passed away in April of 2009.  He was head of all red winemaking at Kendall Jackson and he had his own family winery label called Blair in Northern Napa Valley.

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