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WINERY & VINEYARD EQUIPMENT 92 WINES&VINES January 2018 process is required to obtain a reasonable result: 1) distillation of all alcohol, and 2) reanalyzing with the ebulliometer. This procedure can add 45 to 60 minutes to the test. Enzymatic analysis by CDR and Megazyme can make these analyses whether with or without residual sugar. As simple as these tests appear, analysis of ethanol by these systems is the one test with the greatest de- gree of difference from the traditional means of measuring ethanol in wine. The CDR test takes 11 minutes, and the MegaQuant Wave takes seven minutes. Both tests require some form of sample dilution to get accurate results. Each one requires two measurement steps to obtain a final answer. The Rudolph Alcotest is the simplest test for alcohol measurement. A few drops of wine are placed on their refractometer from a 3-ml sy- ringe. That syringe is then used to inject a 1+ ml of wine into the densitometer that is shown on the LCD screen. The screen allows one to be sure it is completely full. Push start and, in about one minute, a three X replication with a standard deviation result is displayed. In practice, the re- sults will be very close to ebulliometry. Brix: spill-sensitive or splash proof The Hanna refractometer has a 0.1% Brix Resolution and an accuracy of + /- 0.2%. The temperature compensation ranges from 0° to 40° C, and it takes 1.5 seconds to make an analysis. This instrument cannot withstand liquid spillage. Rudolph J457 returns a reading + /- 0.15° Brix at a resolution of 0.01° Brix. Instead of a compensation algorithm, it brings all samples to one temperature, so it takes 30 seconds or less per analysis. This unit is splash-proof and can withstand wet environments. It also has compensation software to detect the cleanli- ness of the sample chamber and can detect whether the sample is covering the prism properly. Its cover protects against evaporation and temperature swings during analysis. Copper test: reduce over-fining complications This test is very useful when monitoring wines that have reductive aromas. Elevated copper in a wine and attempts to eliminate the reduc- tive aromas can result in wine with copper casse (copper instability). CDR WineLab offers this test, which follows the pattern of adding a sample, a reagent, and then measuring. The range of this test covers from 0.05 to 1.2 mg/L. Cold stability: conductivity— a more precise measurement Cold-stability tests are important for all winer- ies. The Edge meter from Hanna incorporates a conductivity probe as one of its options. With a marginal increase in the meter's purchase price, a small winery can add this test to its repertoire. A winery will need to have a cooling source that will reduce the temperature of about 0.5 liters of the wine being tested. Desk- top lab chillers are available and are the easiest and best way to do that. However, if the winery already has a glycol chiller to cold stabilize wine, a DIY cold-stabilization device can be created to move some glycol to chill a small amount of wine to run the test. The test is simple. Using the Davis Protocol, chill wine to 0° C, add 1.5 g/100 ml of cream of tartar, stir or bubble the wine for 30 minutes. Measure the conductivity of the wine at the beginning and end. If the conductivity goes down by more than 5% of the initial measure of conductivity, the wine is unstable. Glucose/fructose: sweetness is knowing your sugar levels Both CDR WineLab and the MegaQuant Wave can measure glucose and fructose, either sepa- rately or combined, and can measure sucrose and other sugars. Most wineries only need combined glucose and fructose to determine sugar levels. Be sure to account for any sucrose additions and assure its complete hydrolysis before using these tests. From grapes to wine, sugar levels can be measured using grams or milligrams per liter. The same test is used to measure the sugars, which usually means dilu- tions are needed to keep the analysis in the linear range of measurement. The lowest amount that the MegaQuant Wave can mea- sure is 40 ppm of sugars, and for the CDR WineLab it is 100 ppm. Heat stability: NTU measurement is better than your eye There are many different methods for testing for heat stability. Use your preferred method for inducing heat stress into your wine. Prior to stressing the wine, filter the sample to 0.45 u, then measure the wine sample with the Hanna Turbidity meter and record that num- ber. Hanna uses their Bentocheck reagent to denature protein, and their formula stipulates that if T2 < T1+2 the wine is stable; other- wise, bentonite needs to be added until the wine meets the formula. There are alternate ways to denature the protein and some minor variations in the formula to calculate results. Malic acid: enzyme analysis is easier and faster than chromatography The CDR WineLab and MegaQuant Wave fol- low their enzyme standard protocol for their two instruments. The test time for the CDR WineLab is four minutes, and for the Mega- Quant Wave it is six minutes. The lowest amount detectable is 5 ppm by the MegaQuant Wave and 50 ppm by the CDR. Micro testing: with this system, you can do integrity checks Microbiological testing is challenging for small wineries. Sartorius has developed a system called Biosart for cell counts that minimizes the difficulties of doing micro testing. The most important additional component that is needed to do integrity tests is a chamber in which to perform the test. These can be quite expensive. Agápi Lab Solutions offers an inexpensive chamber as a kit. Assemble when needed, then disassemble and store it in a box. To conduct a test, put on disposable lab gloves, then spray the inside of the chamber liberally with grocery store sanitizing spray. Use 70% alcohol to sanitize the tips of tongs. Outside the chamber, flame the bottle top (after removing the capsule) and insert im- mediately into the chamber to protect from organisms in the air. Place a sterile Biosart-padded membrane funnel on a vacuum manifold. Remove its lid and turn on a vacuum source. Filter the de- sired amount from the bottle (note the quan- The CDR WineLab offers a multitude of analytical tests including alcohol, Brix, copper, glucose/fructose, pH and free and total SO 2 .