Apple Juice

September 19, 1995
Rev. July 1998
Rev. Aug 2013

In 1995 a series of trials were run pressing apples in the Tampa Works.  Two drums of crushed and chilled apples were flown in from Pennsylvania for the tests.

The apples came from Wentzler Apple Farms, a regional apple cider producer.  They are known for producing a high quality, natural product that is free of preservatives and sediment.  Apple cider is typically a fresh juice product that is not filtered or clarified following pressing.  Since a clear juice is desired, bag or filter presses are used to make apple cider.  All of the apple juice made in the trials was definitely too murky or hazy, with too many suspended solids, to be used as apple cider.

Commercial apple juice is made by filtering the juice that comes from the press.  This is typically done with diatomaceous earth (DE) drum filter presses.  More recent technology uses microfiltration and reverse osmosis (RO).  Centrifuges are of limited use because of their high cost and the small differential in density between the solids and the juice.

A great deal was learned in the tests.  Without the addition of a press aid, the pressing of crushed apple was almost impossible.  The screens blinded, the material slipped in the press, and press capacity went down to a tiny fraction of rated output.

Two presses aids were used, rice hulls and Weyerhaeuser Silvacel (ground wood).  Both appeared about equally effective.  In a commercial operation some optimum blend of the costly and inexpensive press aids could be determined.

The rotating cone option improved the operation a little.  A minor improvement in press throughput was noted.  However, it was felt that this improvement would not justify the additional cost and complexity associated with the rotating cone.

With 3% press aid blended into the apples, yields ranged from 72% to 80%.  This will vary with the variety of apples and the ripeness of the fruit.  Press through put capacity was 50% of the Blue Brochure rating.  In contrast, with 6% press aid, yield was 87% and capacity was up to 65%.

With 0.005" wedgewire screens there was a reduction in press capacity, as compared to using 0.041" perforation.  Since the juice from both screens contained large amounts of suspended solids, it was felt that the perforated screen was preferred.

July 1998 update

The new Fiber Filter may give Vincent an excellent means of penetrating the apple juice market.  Testing will be required.

This year we have supplied a VP-12 press to Cliffstar that will be used in producing apple juice.  In addition, we are rebuilding some of their older Vincent presses.

August 2013 update

Since the last update in 1998, the market has shifted to where most apple juice is produced in China.  Also, the production process has shifted from using screw presses to using enzymes to break down the fruit so that centrifuges (decanters) are used.  This method of producing juice achieves the very highest juice yields.

 

Issue 32