Making Wine - Crushing and De-stemming

The second step in wine making series is Crushing and De-stemming the grapes.

After the grapes have been harvested it is often a mad dash to get them crushed and destemmed. The objective of crushing is not necessarily to squeeze all of the juice out of the grape, but to split the external skin and allow the juice to start its run, giving the sugar from the juice its first chance to mingle with the natural yeast found on the grape's skin. It's the combination of yeast and sugar that produces the wine's alcohol, via the yeast converting the sugar to alcohol and carbon dioxide. The "crush" happens in one of two ways - again by mechanical means with a heavy spiraled steel roller or the more traditional approach that you see in all of the fun Italian wine-themed movies - the famous grape "stomp."

At this point the grape stems are separated from the juice, or "must" as it is referred to at this phase in the game. This is also the juncture where red wine grapes and white wine grapes take different paths. If a wine is destined to be a red wine then the grape skins (not the juice, which is virtually clear) that provide the color characteristics and the tannin contributions for a red wine. However, if the goal is a white wine, then the grape skins are removed along with the stems at this phase of the process and the grapes are pressed prior to fermentation.

Pressing The Grapes

Pressing, usually done right after the crush for white grapes and after fermentation for red wine grapes, is basically taking the sticky grape solids left from either the crush or fermentation and squeezing them to get a very thick liquid that can be used to enhance both color and flavor of the presumptive wine to be.

Stay tuned for our next posting on Wine Fermentation.

Ever wonder how wine is made?

You enjoy that bottle of wine, but have you ever wondered what goes into making it?

There are many steps in the wine making process. They are: harvesting; crushing and destemming; fermentation; malolactic fermenation; maturation of wine; fining and filtration; blending and bottling. I will discuss each step in deteail over a series of blog posts to help educate our readers on the process that goes into making that great bottle of wine that you so enjoy!

The First Step: The Wine Harvest

The vineyards are a critical determinant in the end product wines for each and every vintage. Vineyards are like the wine's bassinets, where early grapelife begins and flourishes, for all wine is truly birthed on the vine. The vineyard's location, climate, terrain, soils, vines and rootstocks, irrigation systems and pest management controls all factor into the final product in one way or another. Sun exposure and time on the vine both play a key role in the grape's development and specific sugar levels.

Winemaking commences with the annual grape harvest and can be accomplished by either mechanical harvesting equipment (usually easiest for vineyards that lie on relatively flat land) or hand harvesting. Hand-harvesting affords more precise selection and often does a better job of protecting the grape’s juice content from oxidation due to damaged skins. Mechanical harvesters offer a more efficient, often cost-effective, process and are well-suited for large vineyards that lay on a flat patch of earth. The type of harvest - hand-picking, mechanical harvesters or a combination of the two, is largely influenced by the winemaker’s final wine style goals as well as budget.


Stay tuned for our next posting which will talk about Crushing and Destemming.