Vocab Flashcards
Mannoprotein
Proteins with high carbohydrate content, especially mannose sugars. a natural part of yeast cell walls. tartrate stability, wine texture. important part in lees contact.
An additive used to prevent tartrate crystal formation.
It has been observed for many years that wines aged on lees are more stable for both potassium bitartrate and protein haze, and certain mouthfeel characteristics are well known. These effects are in large part due to the mannoproteins that are released from the yeast cell wall during autolysis.
Lysozyme
Isolated from egg whites, this enzyme will degrade the cell wall of gram positive bacteria, but will not affect yeast or gram negative bacteria such as Acetobacter.
Commonly used to delay MLF or destroy the bacteria (while leaving the yeast alone) in the Champagne process in the liqueur de tirage
CMC
Carboxymethylcellulose
Is a crystalization inhibitor. added at the very last step before bottling. Can interact with proteins to form a haze so the wine must be protein-stable first.
Ascorbic Acid
Vitamin C!
Ascorbic acid is a quick-acting and powerful antioxidant that is used in white winemaking to protect against light and short aerations, such as racking and bottling. It works by rapidly converting dissolved oxygen into hydrogen peroxide before it has a chance to react with oxidative enzymes and cause browning. However, this hydrogen peroxide itself needs to be removed from the wine in order to avoid the very phenomenon that was trying to be avoided in the first place, namely oxidizing the wine. The answer lies in always making sure that the free SO2 levels are correct, both before the ascorbic addition is to be made and after. Addition rate is around 50 mg/l (ppm) as long as the free SO is maintained at 30 mg/l (ppm).
Bordeaux mixture
combination of Copper sulfate and Calcium oxide, used to fight downy mildew.
Total Package Oxygen (TPO)
Total package oxygen is the summation of dissolved oxygen, headspace oxygen, and oxygen initially contained in the closure, and is typically around 0.6 – 1.5 mg O2 under the best conditions, and may be as high as 2.3 – 7.0 mg O2 if care is not taken to exclude oxygen at bottling
Pinot Droit
In the 1960s, in response to widespread disease in Burgundy, France started certifying disease free clones. Pinot Droit was an early attempt - large berried, low quality.
Schist
finely layered metamorphic rock derived mostly from clay. Found in many places, notably the Douro, Priorat, south of France.
pH
negative logarithm of Proton concentration. Measures the “active” hydrogen ions in a solution. Although related to TA, the buffering capacity of the metals present in juice or wine influence the final pH.
pH affects viticulture, fermentation kinetics, color, extractive, SO2 efficacy, microbial activity, stability.
Michet
a virused clone of the commonplace Nebbiolo Lampia (fanleaf virus). Highly valued for the quality and concentration. Small, sparse clusters. Popularized by Marchesi di Barolo.
Sand
Broken up pieces of quartz (SiO2) with particles that average 2mm in size. Low fertility, rapid drainage, inhospitable to phylloxera.
Argile
The Loire term for clay, especially as found in the eastern end of Sancerre + Pouilly-Fume.
TDN
Trimethyl Dihydronapthalene - the petrol smell in Riesling
Comes from:
- sun exposure on clusters
- ripeness
- water stress
- warm soils
DAP + Fermaid
DAP: “junk food” = pure N
Fermaid: “salad” = N + other amino acids + vitamins that help support a healthy fermentation
Dap = 5x cheaper than Fermaid and 5x more expensive
Isinglass
a semitransparent whitish very pure gelatin prepared from the air bladders of fishes (such as sturgeons) and used especially as a clarifying agent and in jellies and glue
Monoterpenes
Monoterpenes are important contributors to grape and wine aroma. Moreover, certain monoterpenes have been shown to display health benefits with antimicrobial, anti-inflammatory, anticancer or hypotensive properties amongst others.
Common wine scents = rose, lychee, coconut, lime
TVI
Temperature Variability Index
DAP
Diammonium hydrogen phosphate (DAP) Source of yeast available nitrogen to promote the rapid start of alcoholic fermentation
APPLICATIONS Yeast nutrient for use during fermentation Prevention of H2S formation during fermentation
DOSAGE 10-30 g/hl (0.8 – 2.5 lb/1000 gal) 10 g/hL of DAP provides 21 ppm of yeast available nitrogen (YAN)
LEGAL ADDITION LIMIT
USA – 96 g/hL (8 lb/1000 gal)
EU – 100 g/hL (8.3 lb/1000 gal)
PET
Polyethylene terephthalate - a common plastic. Starting to be used for wine storage in lieu of glass bottles. Saintsbury’s in UK came out with some cheaper wines (Oz Shiraz and NZ SB).
Supported by WRAP (Waste Resources and Action Programme) initiative signed by UK retailers.
Advantages:
- lighter and easier to transport (54g vs 400-550g for standard glass bottle)
- recyclable
- no breakage
Disadvantages:
- Image
- Oxygen - allows more oxygen ingress than glass, reducing freshness and shortening shelf life, 12-18months (roughly same as bag-in-box)
metatartaric acid
Metatartaric Acid is used for preventing tartrate precipitation, although its effect decreases at higher temperatures and is not permanent. Is cheap and good for wines meant to be consumed young and fast. EU upper limit is 100mg/L. Additions of metatartaric acid in the United States are not permitted.
Potassium Metabisulfite
Potassium Metabisulfite, (often referred to as “SO2”, “sulfites” “meta”, or “meta-bi”) has several uses in winemaking. At the crush, sulfites are generally used to help control the spoilage bacteria and indigenous yeast that may already be present both on the fruit and in the winery (i.e. on the picking bins, processing equipment, tanks, tubing, etc). In addition, sulfites also help to inhibit the enzymatic browning of both musts and finished wines so that all of their delicate complexities can be preserved. Later, during storage and in the bottle, sulfites at the proper levels will further protect a wine by continuing to inhibit spoilage organisms, as well as by scavenging oxygen.
diethylpyrocarbonate
Is either the same thing as DMDC (velcorin) or a precursor.
Velcorin breaks down to methane and CO2 in bottle.
Needs to be applied by a certified operator using a special dosing machine.
Example: Vivier wines.
