Crusher-stemmers

The first crusher-stemmers were largely modifications of the old Garolla type. They were made of iron and could handle 50-100 tons per hour. Excess iron pickup was a major problem until stainless steel was introduced after World War II. 

The Garolla-type crusher-stemmers are used widely in this viticultural area. They are employed in a variety of sizes—very small ones, which are... 

An exception to the full utilization of the Garolla crusher-stemmer is the case of V. vinifera cultivar Pinot noir. In many wineries with this variety, the stems that are separated from the grape by the crusher-stemmer are added back to the must. In general, the entire amount of stems removed from the grapes is not returned to the must. Rather, a measured percentage is added back. If the stems are chopped into small pieces, a level on the order of 10-30 percent generally is added back. However, up to 80 percent chopped stems have been returned to the must by one winery. Where whole stems are added back to the must, up to 100 percent of the stems have been utilized by some wineries. 

For the production of white wine, it is almost universally accepted that a relatively clear juice of 0.5-2.0 percent suspended solids is desired for fermentation. This is achieved by separating the juice from the skins, pulp, and seeds. Many of the small wineries use a horizontal basket press to receive their fresh must. These presses utilize either an inflatable bladder or a movable piston to press the crushed grapes. In many cases, the must is pumped directly to these presses from the crusher-stemmer. An exception to this method of operation in small wineries is the case where skin contact is desired. Several wineries will allow maceration for from four hours to twenty-four hours for V. vinifera cultivars Chardonnay and Gewiirztraimer. 

Because of the probability of residual microorganisms on equipment, it is important to evaluate the effectiveness of any sanitation program. Sampling sites on winery equipment should be selected to include aU points that are liable to shelter microorganisms. Of importance would be to sample direct-contact surfaces such as crushers, stemmers, presses, the interior of pipelines, conveyors, and tanks. Other areas to sample include where indirect contamination could occur such as condensation from ceilings or equipment, aerosols, and lubricants. 

Receiving hoppers are available in various designs. In small wineries, they may be installed directly above the crusher-stemmer and filled... 

The crushers were generally located above the fermenting tanks. Roller crushers followed by a stemmer was the usual practice. As a rule grapes are fermented without the stems in California. The exception noted was when the stems were dry and were then allowed to pass into the fermenting tanks, so that tannin can be drawn from the stems. This was probably only for red wines. 

Preparation of the must. The must, or juice, to be fermented is extracted by passing the fresh grapes through a stemmer-crusher, after which the juice is treated with sulfur dioxide to kill any undesirable wild yeasts. NOTE WELL Because sulfites trigger severe reactions among some people, since June 1978, the Bureau of Alcohol, Tobacco, and Firearms has required that all wines containing more than 10 parts per million of sulfites carry the phrase "Contains sulfites" on the neck, back, or side panels of containers. 

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