Intro to Wine Oenology

Question 1

How can you harvest?

Answer 1

my hand (manual) or using a machine. You can also harvest at night in warm climate areas to control the speed of early fermentation

Question 2

What does MOG mean?

Answer 2

Material other than grapes. In machine harvested grapes, the trunks are beaten and the grapes fall off. One advantage is that you don’t have to destem the grapes. Of course, MOG includes dead birds, snakes, etc. Machine harvesting is much cheaper, but requires flat land and standard trellising.

Question 3

What can you tell me about crushing?

Answer 3

In some cases (like Pinot Noir) it might be appropriate to remove the stems and leave mostly whole berries. This leads to longer, slower fermentation and less extraction of bitter substances from grapes. This is called whole-cluster fermentation.

More common is teh practiec of removing stems and splitting all the berries - most red wines are made this way.

For high-extract wines, such as Port, teh grapes are destemmed, and the berries completely broken apart with some shearing of tissues and bruising of seeds.

Question 4

What is must?

Answer 4

The crushed grape juice is known as must. Special must pumps can be used to move it into fermenters.

Question 5

What is chaptalization?

Answer 5

This means to add sugar. If your grapes come in at 20 Brix, there may not be enough sugar to generate the final alcohol concentration that will enable a stable wine, or because they are not all the way ripe, there may be “green” or “Weedy” flavors. Many people will add sugar to 24 Brix or so before fermentation starts.

Question 6

What is bleeding?

Answer 6

Juice removal is referred to as bleeding. This is a Burgundian practice which involves removing a portion (up to 20%) of juice from freshly crushed grapes in order to increase teh ratio of skins and seeds to juice in teh remaining must.

The result is a wine with increased flavor intensity, color, and tannis.

Question 7

How is Saignee Rose made?

Answer 7

1. Red wine grapes are picked when optimally ripe for red wine making
2. Grapes are crushed and put into a fermentation vat
3. After a short period of time (From 2 hrs to 2 days) a portion of the juice is bled off.
4. The Saignee rose finishes fermenting on tis own.
5. Some producers age their Saignee rose in oak barrels

Question 8

What are other ways to go pink?

Answer 8

Blending method: The blending method is when a little bit of red wine is added to a vat of white wine to make rose; these wines will have about 5% of red added in. This method is uncommon with still rose wines but happens much more in sparkling wine regions. Like a rose champaigne (Chardonnay with a smidgen of red pinot noir)

Maceration method: is when red wine grapes are let to rest, or macerate, in the juice for a period of time and afterwards the entire batch of must is pressed and is finished into a rose wine. The maceration method is the most common type of rose that we see available and is used in regions like Provence, Languedoc-Rouisillon, where rose is as important as red or white.

Question 9

What is prefermentation?

Answer 9

This is known as maceration or cold soaking. It is another French technique that has been adopted in the New World. Grapes are crushed into a sealable container, then chilled and left alone for up to three days before inoculation with yeast (remember that the usual practice is to inoculate immediately after crushing). This gives the anthocyanin pigments a chance to be leached from the skins in an aqueous environment, as opposed as when the ethanol is present.

Question 10

Why is prefermentaion used by some wine makers?

Answer 10

Because they feel that with low-color-intensity grape varieties this technique results in a more deeply-colored, richer wine.

Question 11

What does cold soaking do?

Answer 11

Cold soaking is a process that happens before there’s alcohol in the mix. The theory of cold soaking is to carefully extract color and fruit flavors from the skins without extracting bitter tanning. The total time that grape skins touch a wine is maceration time.

It produces a more colored and bold wine without all the tannin.

Question 12

What are the qualities of an open fermnetation vessel?

Answer 12

1) They allow for dissipation of heat generated during fermentation (+)
2) They allow significant amount of ethanol to escape by entrainment and evaporation (+ or -, depending on the sitaution)
3) they provide more contact with oxygen (+ during the early stages of fermentation; potentially disastrous at completion of, and after, fermentation)
4) they are practical for small volumes (-)
5) they allow for gentle cap management; e.g.., manually punching down the cap (+)
-They are not suitable for extended maceration (-)

Question 13

What do closed fermenters offer?

Answer 13

1) They are easily sealed (+)
2) They make warming and cooling of the must easier (+)
3) They can hold large volumes of grapes (+)
4) They are multi-purpose, can be used for storage and for white wine fermentation (+)
5) They make cap mgmt difficult (-)
6) They have a tendency to allow teh fermentation to get too hot (-) and must sometimes be refrigerated

For aromatic wines, closed fermentation is ESSENTIAL or the floral aromas would evaporate

Question 14

What is a hydrometer?

Answer 14

Hydrometers measure the density or specific gravity of a solution.

Since sugars are more dense than water, the initial specific gravity of grape juice is high, but it decreases during fermentation and you can predict the final alcohol concentration by the initial specific gravity

Question 15

What can you tell me about secondary fermentations?

Answer 15

Malolactic bacteria (malolactic fermentation) convert malic acid (malate) to lactic acid (lactate)

This converts an appley tasting wine (tart) to a butter tasting wine (smooth)

This happens naturally in Burgundian technique but must be cultured in US

Sometimes, only half of the barrels are cultured, giving a mix of appley and buttery flavor profiles

Question 16

What is Oenococcus oeni?

Answer 16

This is a type of LAB (Lactic Acid Bacteria) that is of particular interest because they can carry out the second fermentation - producing best results.

Question 17

What is lees?

Answer 17

These are the yeast sediments in the bottom of the fermentator or barrel

Question 18

What is battonage?

Answer 18

This is when you stir the lees (yeast sediments in the bottom of the fermentator or barrel)

Letting the wine rest on the lees is called aging “sur lie.” This adds a creamy mouth feel and an old beer-like note that’s actually pleasant.

Question 19

What is Early Drop?

Answer 19

This is ESSENTIAL for wine expected to be drunk at the time of the purchase.

This is a technique where the wine is pressed before it is finished fermenting. The fermentation typically finishes in barrels, but the last 5% (or so) of the sugar ferment without the skins. This reduce color, but also reduce tanning, and make the wine require less aging and be ready to drink MUCH sooner.

Question 20

What do people use sulfite for wine making?

Answer 20

It is mostly use to sanitize all the surfaces that would come in contact with grapes or their juices. Using sulfites in the winery in the US means you can’t call your wine organic. Note that in Canada and Europe, organic wines can do and do contain sulfites.

Question 21

What does “made from Organic grapes” mean?

Answer 21

It is wine made from organic grapes, but sulfites were used int he winery. Here, wine can have up to 100 ppm sulfite. Note that sulfite occurs in grapes naturally, up to 50 ppm, so it is impossible to have a sulfite-free wine. In the US and Australia, wine with over 10 ppm sulfite must contain the label “contains sulfites”. Note that most organic wines will contain this much sulfite naturally.

Question 22

Many people think they are allergic to wine or that it gives them headaches. What is a possible reason for this?

Answer 22

Most think it is due to sulfites, but more likely it is due to the histamine (a compound found naturally in wines). Try taking an antihistamine before drinking.

Question 23

What bacteria can reduce the histamine?

Answer 23

Malolactic bacteria can reduce the histamine (and other biogenic amines) if you use the right strain of baceria.

Question 24

Describe the pumpover (or remontage) process

Answer 24

Pumpovers can extract higher amounts of tannin in a wine depending on the frequency and force. Some pump over systems are basically wine sprinklers, offering a gentler extraction and some aggressively stir up the fermentation tank. For larger fermentation tanks in commercial operations, much needed oxygen comes through a pumpover device.

Question 25

What is a punch down (pigeage)?

Answer 25

Punch down, on the other hand, are a very delicate way of stirring a wine. They keep skins from getting too extracted and little to no amount of added oxygen in the fermentation. Punch downs are typically done by hand and are more popular with non-interventionist winemaking.

Question 26

Which type of process (punch down or pumpover) produces wine that is more intensive?

Answer 26

Pumpover results in a more intense wine than punch down.

Remember, these processes happen during fermentation on average 3 times a day.

Question 27

What are the typical oak species in America?

Answer 27

Quercus alba which is a white oak species that is characterized by its relatively fast growth, wider grains and lower wood tannins.

It is found in most of the easter US as well as Missouri, Minnesota, and Wisconsin where many wine barrels are from. In Oregon the Quercus garryana white oak has started to gain usage due to tis closer similarities to European oak.

Question 28

What are the types of oak used in France?

Answer 28

Both the Quercus robur (common oak) and Quercus petraea (white oak) are considered apt for wine making, however, the latter is considered far superior for its finer grain and richer contribution of aromatic components like vanilla and its derivatives, methyl-octalactone and tannis, as well as phenols and volatile aldehydes.

Question 30

Where does French oak usually comes from?

Answer 30

It comes from one or more primary forests: Allier, Limuusin, Nevers, Tronncais and Vosges.

Question 31

What flavors does charred oak usually imparts?

Answer 31

It adds vanilla, light toasty notes and significantly enhances wine. Overdone, the wine just smells like wood and smoke, and the fruit notes are overwhelmed.

Question 32

What is Racking?

Answer 32

Racking is the process of moving the wine from an old barrel to a new barrel, leaving the sediment behind.

Question 33

What is the purpose of Racking?

Answer 33

Racking is the process of moving the wine from an old barrel to a new barrel, leaving the sediment behind.

THIS SERVES TO CLARIFY THE WINE, BUT ALSO ADDS SOME OXYGEN WHICH HELPS “SOFTEN” THE WINE.

You may also be moving the wine from a “neutral” barrel to a “finishing-oak” barrel.

Question 34

What does French oak add to wine?

Answer 34

French oak barrels add vanilla, smoke, toasty, woody flavors to wine.

Vanilla is the human equivalent to catnip

Question 35

Explain coopers.

Answer 35

People who make barrels are coopers. Barrels are called cooperage.

Question 36

What is fining?

Answer 36

Fining is the act of adding agents to wine in order to selectively remove certain substances in it.

Question 37

What’s the purpose of fining in red wine?

Answer 37

To either clarify the wine or reduce its astringency. Very few reds require bentonite fining, since any unstable proteins have had a chance to react with tannins and precipitate out.

Occasionally, a red wine with obvious hydrogen sulfide (H2S) will be fined with a small amount of copper sulfate.

Question 38

What is cold stabilization?

Answer 38

Cold stabilization is the process used in winemaking to reduce tartare crystal (generally potassium bitartare) in wine. These tartate crystals look like grains of clear sand, and are also known as “wine crystals” or “wine diamonds”. they are formed by the union of tartaric acid and potassium, and may appear to sediment in the wine, though they are not.

During the cold stabilizing process after fermentation, the temperature of the wine is dropped to close to freezing for 1-2 weeks. This will cause the crystals to separate from the wine and stick to the sides of the holding vessel. When the wine is drained from the vessels, the tartrates are left behind. They may also form in wine bottles that have been stored under very cold conditions.

Most whites need to be cold stabilized, since they will likely be refrigerated.

Question 39

What can you tell me about wine and filtration?

Answer 39

Not all wines are filtered. Ohio Law requires filtration, but they do not specify the pore size of the filter, so you can use an open mesh.

Filtration removes flavor, so you want as little as necessary.

Question 40

What is fining?

Answer 40

White wines usually require fining with varying amounts of bentonite, in order to achieve stability with regards to heat-sensitive proteins.

Question 41

What are the largest cork producers in the world?

Answer 41

Portugal with 50% followed by Spain with 30%

Question 42

What are alternatives to wine closure to avoid TCA contamination?

Answer 42

Artificial corks -> Artificial or synthetic corks are designated to match real cork in size and shape and to be used in the same sort of bottles as real corks.

Screw caps -> Screw caps seal considerably better than natural cork, letting in far less oxygen and disallowing any risk for cork taint.

Glass stoppers -> A relatively new product known as “vino-seal” has hit the market, consisting of a glass plug that fits in the bottle’s neck and over the lip.

Crown caps –> Crown caps are the same little metal caps found on the tops of beer bottles and are commonly used in sparkling wine production.

Note: Trichloroanisole (TCA) is a chemical compound that can contaminate wine and other products, causing a defect known as “cork taint” or “corky smell”.

Question 43

What can you tell me about the wholesale cost in terms of mark-up?

Answer 43

Wholesale cost is 100% mark-up

Question 44

What can you tell me about the retail cost mark up?

Answer 44

Retail cost is 50% mark up.

Restaurant cost is triple whole sale.