CA1258438A

CA1258438A - Process for producing apple juice and apple wine

Info

Publication number: CA1258438A
Application number: CA000486533A
Authority: CA
Inventors: David W.S. Riddell
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-07-09
Filing date: 1985-07-09
Publication date: 1989-08-15

Abstract

Apple juice is produced in such a way as to avoid oxidation deterioration during extraction and subsequent juice processing. This improved juice may be consumed as is or it can be fermented and used to produce a high quality apple wine.

Description

BACKGROUND OF THE INVENTION
This invention relates to the production of an improved apple juice and also to the production of apple wine from this apple juice.
Existing processes for extracting the juice from apples usually involve a preliminary mechanical macerating, grinding, or crushing of the fruit to sufficiently break down and rupture the cellular structure of thP apples as to form a slurry or pulp, which is then pressed, using commercially available equipment, to extract the juice. Typically, duriny these processes, a considerable degree of oxidation takes place, imparting to the extracted juice a flavour distinctly different from the flavour of fresh apples. This distinctive flavour has become widely recognized and accepted as the flavour of apple juice or sweet cider and while not generally considered undesireable in the types of liquid apple products that presently enjoy wide commercial distribution, these flavours are considered most undesireable in alcoholic beverages such as cider or apple wlne .
SUMMARY OF THE INVENTION
This invention has as its main object, the substantial overcoming of the problems associated with the "off" flavours developed during the mechanical macerating, crushing and pressing procedures currently employed to extract the juice from fresh apples, and to produce a liquid extract or juice which substantially retains the flavour of the fresh fruit from which the juice is extracted. Another object is to provide a juice which is free of detectable flavour similar to that usually associated with commercially produced apple juice.
~ nother object of the invention is to eliminate the preliminary step of reducing whole, fresh apples to a pulp or slurry, by mechanical means, prior to pressing to extract the juice.

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Accordingly, the invention in one aspect provides a process for producing apple juice which comprises the steps of hard freezing sound apples, then thawing said apples in a substantially air-free environment and pressin~ the thawed apples to extract the juice therefrom.
A further object of the invention is to prepare a balanced must from the apple juice and to ferment this must to yield an apple wine which has organoleptic characteristicæ usually associated with a quality, white, grape wine, rather than the organoleptic characteristics of most commercially produced apple wines presently sold in Nor~h America.
Other and still further objects, features, and advantages reside in the various combinations of steps hereinafter set forth and in such other and further matters as will be understood by those skilled in this art.
DETAILED DESCRIPTION OF PREFERRED FORMS OF THE INVENTION
Preferred forms of the invention will now be described, by way of example. For definitions of the invention reference should be had to the claims appended hereto.
~eneral The production method described hereafter permits the extraction from apples of juice having a unique, fresh flavoured quality by inhibiting the otherwise extensive natural degradation believed to be due to oxidation of the fruit juice, thereby minimizing the "canned" flavour which normally characterizes non-alcoholic apple products produced by most conventional methods. Also described is a method for conversion of the juice to wine of suitable alcohol content by means of a controlled fermentation process.
Raw ~Jaterial Selection The apples used in the apple juice process are clean, selected, fresh, whole tree ripened apples with a ~25!3~. 3~

minimum of blemishes or bruising. Windfalls or otherwise severely damaged fruit must not be used in the process.
Freezing Following picking and normal cleaning and grading, fruit selected for the apple juice process is randomly packed in suitable containers.
The containers of apples are then placed in a conventional freezer unit and subjected to freezing in air at such a temperature and for such a period of time that each individual fruit becomes "rock hard". This is accomplished when the temperature of the apples has been lowered to approximately minus 1~ degrees Celsius to minus 23 degrees Celsius.
Thawing At an appropriate time (after the apples have been frozen to "rock hardness"), the frozen apples are removed from the freezer and, with minimum delay, immersed in a water bath contained in a suitably insulated vessel or tank of such volume that the fruit, as it thaws, will be completely submerged at all times.
The frozen apples are held submerged in the water bath by suitable means until completely thawed. The apples, while thawing, are kept (as completely reasonably as possible) submerged in water for two main reasons;
firstly, to exclude air, and secondly, because water is a low cost, sanitary, efficient heat exchange mediu~ to effect relatively rapid thawing and simple te~perature control of the whole mass. ~itrogen, or some other inert gas such as carbon dioxide would probably work but would likely prove to be more costly and more complex.
The temperature of the water bath is controlled by suitable means such that, initially, at the time of adding the frozen apples, it lies within the range 50-70F
(10-21C), while at equilibrium conditions, that is, when the apples have completely thawed, the temperature of the . ~ ~

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whole mass of apples and water does not substantially exceed about 3 degrees Celsius.
Additionally, the subsequent steps of pressing, filtering, straining etc. are carried out at low temperature, i.e. not greater than about 3C and with minimal air contact to substantially eliminate oxidation deterioration.
Pressing Thawed apples are removed from the water bath, drained of excess moisture, and immediately pressed whole in a suitable apparatus designed for rapid juice extraction (as described below). The extracted juice is continuously strained and filtered to remove any apple pulp, seeds, pieces of core and other deleterious particulate matter and then directed by suitable means tpump or gravity flow) into storage tanks designed to minimize the contact of the extracted juice with air. All handling of the thawed apples and juice extraction, straining, filtering and storage are carried out in an enclosed space as noted previously wherein the ambient temperature is controlled in the range 0.0 degrees Celsius - to 3.3 degrees Celsius.
Commercially avallable equipment can be used to extract the juice from apples frozen and thawed according to the present process. A first choice is the "Squeezebox" Cider Press/ made by Goodnature Products Inc., P.O. Box 233, East Aurora, New YorX, 14052. Other manufacturers of suitable juice extraction equipment are:
Rack & Cloth presses made by J.D. Products & Design, 1165 30 Lincoln Road, Allegan, Michigan 49010 and the Horizontal Drum Juice Press manufactured by Mearelli of Italy imported by Orchard Equipment & Supply Co., Conway, Mass. 01341.
Juice Packaging The clear apple juice is withdrawn from storage within 48 hours, and further processed and packaged in 1~25~ 3~3 sterile containers in such conventional manner as the requirements of product marketing may dictate.
The freezing to "rock hardness" and subsequent thawing under water to a temperature not in excess of 3 degrees Celsius accomplishes the rupturing of the natural cellular structure of the apples without the risk of oxidation from exposure to air which is associated with mechanical pulping of the fruit. Also, the maintaining of a cold ambient temperature throughout all of the juice extraction, clarification and storage processes helps to minimize the risk of oxidation and accompanying development of "off" flavours. Apples which have been frozen and subsequently thawed according to the foregoing procedures can be pressed, to extract a high yield of juice, using "state of the art" conventional fruit pressing equipment without the preliminary step of mechanical grinding, pulping, shredding, or macerating.
Apple Wine Used as the base for must preparation the apple juice extracted according to the foregoing procedures enables the fermentation of a light, white apple wine which is organoleptically equivalent to a light, white wine produced from a must based on vinifera grapes.
The apple juice, instead of being packaged, may be used in the preparation of apple wine in accordance with the following procedure.
Must Preparation Within 48 hours, preferably, of extraction, the chilled, clear apple juice is withdrawn from storage and placed in a must preparation container of suitable size and type of material. ~owever, the apple juice may be stored for periods longer than 48 hours. In this case, it is the practice to dose the juice with sulphur dioxide.
This is done by dissolving 175 to 200 parts per million by weight, of potassium metabisulphite in the juice to kill 5B~

off any wild yeasts that may be present. Also, the ~uice is stored under refrigeration at around 3 degrees Celsius. If the foregoing is not done, there is a likelihood that auto fermentation induced by wild yeasts present on the apple's skins will occur, or bacterial spoilage may take place. This procedure ensures that when the must is inoculated with an active wine yeast starter, all of the fermentation is accomplished by that strain of wine yeast, and not by an inferior wild yeast strain.
Each volume of apple juice is then diluted by the addition of about 1.75 volumes of deionized (or equivalent purity) water. De-ionized water is desirable because it is at least as pure as distilled water, and can be produced at a lower cost. Actually, ordinary, good quality tap water, well water, spring water, stream water, etc. can be used. ~ighly chlorinated water may kill the yeast and stop or inhibit fermentation. Water that has any "off" odour or flavour is unacceptable as this will liXely be carried over into the finished wine. Also, water that is alkaline will consume greater quantities o acid in the must formulation. Water that contains dissolved heavy metals may produce cloudy wine. As is well known in the wine making art, the quality of the water used in the preparation of the must is critical, but difficult to define in precise terms.
Sugar is then added to the must liquid in su~ficient quantity such that the specific gravity of the solution is in the range of 1.080-1.090, measured at 70F.
A combination of food grade acids, such as, but not limited to, citric, tartaric, malic, and lactic acids is then added to th~ must in sufficient quantity such that the total acidity of the mixture is in the range 0.65% to 0.95% referenced to tartaric acid equivalent.
Trace quantities of yeast nutrients, as well as pectic enzyme and grape tannin are than added to the must sufficient to provide an environment conducive to optimum fermentation and to eliminate the formation of pectin induced haze. Yeast nutrients are added to the must to aid in a rapid development of an active vigorous yeast colony. Typical added nutrients would be ammonium phosphate-dibasic---400-500 p.p.m. (parts per million) and Vitamin B-1 (thiamine hydrochloride) 0.5-1.0 p.p.m. Other combinations of nutrients are possible, but they must supply the growing yeast colony with an adequate quantity of the essential elements nitrogen and phosphorous as well as Vitamin B-l. In order to support the growth of a healthy vigorous yeast colony, trace quantities of cobalt, copper, iron, zinc, iodine, magnesium, and sulphate are also necessary. These are usually provided in sufficient quantities by the apples and the water used in must preparation. Obviously, if de-ionized or distilled or reverse osmosis water is used, there may well be a need to introduce these materials in making the must. As the ash of yeast contains a significant amount of potassium salts, potassium is also an essential component of a wine must.
This element is usually present in sufficient quantity as the result of sulphiting with potassium metabisulphite, but if sulphiting is done by the addition of sulphurous acid or sulphur dioxide, the resultant defficiency of potassium can be compensated for by the addition of 250-500 p.p.m. of potassium phosphate.
The temperature of the must in the preparation container is then adjusted by suitable means and held in the range 70F-80F (21.1C-26.7C).
~ When the must temperature is stabilized in the proper range, a quantity of active wine yeast is then added sufficient to ensure initiation of fermentation, and the liquid stirred vigourously. ~he wine yeast used is classified as "Saccharomyces Cerevisiae variety Ellipsoideus" usually referred to as S. Ellipsoideus. Any ~ - 8 :, , strain of this yeast should be capable of producing a good wine, although some slight difference in flavours and aromas might develop from using various different strains of this yeast.
Primary Eermentation Following yeast addition and mixing, the must is immediately transferred by suitable means to a primary fermentation tank fitted with an inspection port and air tight clesure, as well as a suitable vent for release of carbon dioxide gas, temperature control and mixing devices.
Temperature of the liquid in the primary fermentation tank is strictly controlled in the range 70 F - 80 F (21.1 C - 26.7 C) during the approximate seven day period of this processing stage. If necessary at this stage, small quantities of additional yeast and/or nutrients may be added to the must to promote active fermentation.
Sec`ondary Fermentation When the specific gravity, as measured periodically by hydrometer, of the fermenting must or wine has fallen to the range 1.010 to 1.030, the liquid is immediately transferred by suitable means in sufficient quantity to fill a closed vessel or tank fitted with a temperature control device and a fermentation lock, and held for a period of approximately four weeks. The temperature of the wine in the secondary fermentation stage is held in the region of 45 F - 80 F
(8.1 C - 26.7 C).
Tertiary Fermentation Wine from the secondary fermenter is carefully transferred or racked at the end of approximately four weeks to a similarly sized and fitted final settling tank, where the liquid is held for a further period of 12 to 14 weeks. The temperature of the wine in the tertiary 125 f~ 3~
g fermentation stage is held in the range of 45 F - 70 F
(8.1 C - 21.1 C).
Wine Storage and Packaging After final settling, the maturing wine is filtered, chilled, and transferred to suitable refrigerated, closed storage tanks to await bottling. The wine is withdrawn from cold storage as required and further processed and packaged in such conventional manner as the requirements of product marketing may dictate.
Wine Making Equipment All equipment, tanks, vessels, valves and piping utilized in the apple wine process are made of suitable inert materials, such as stainless steel, polythylene, and/or glass as is generally known in the art.
The above process yields an apple wine having organoleptic characteristics commonly associated with good quality white grape wines rather than the organoleptic characteristics of most commercially produced apple wines presently sold in North American.

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Claims

1. A process for producing apple juice which comprises the steps of hard freezing sound apples, then thawing said apples in a substantially non-oxidizing environment and immediately pressing the thawed apples to extract the juice therefrom.

2. The process of claim 1 wherein said apples are immersed in a water bath during said thawing step.

3. The process of claim 2 wherein said water bath temperature is controlled such that at the time of immersing the frozen apples the water temperature is from about 10-21°C and, after thawing of the apples and equilibrium conditions have been reached, the temperature of the apples and water does not exceed about 3°C.

4. The process of claim 1, 2 or 3 where said apples are fresh, whole, tree ripened, and with minimal bruises.

5. The process of claims 1, 2 or 3 where said apples are fresh, whole, tree ripened, and with minimal bruises and wherein said apples are cooled to about -18 to -23°C
during the freezing step.

6. The process of claim 1, 2 or 3 wherein said pressing step and subsequent steps of filtering and storing the juice are carried out at low temperatures with minimal air contact to substantially eliminate oxidation deterioration.

7. The process of producing an apple wine comprising utilizing the apple juice produced according to any of claims 1, 2 or 3 to produce a wine must, inoculating the must with a wine yeast and allowing the inoculated must to ferment.

8. The process of producing an apple wine comprising utilizing the apple juice produced according to any of claims 1, 2 or 3 to produce a wine must, inoculating the must with a wine yeast and allowing the inoculated must to ferment and wherein, in preparation of the must, each volume of apple juice is diluted by the addition of a selected volume of clean water, with sugar, food grade acids and yeast nutrients also being added to form the must.

9. The process of producing an apple wine comprising utilizing the apple juice produced according to any of claims 1, 2 or 3 to produce a wine must, inoculating the must with a wine yeast and allowing the inoculated must to ferment and wherein, in preparation of the must, each volume of apple juice is diluted by the addition of a selected volume of clean water, with sugar, food grade acids and yeast nutrients also being added to form the must, and wherein the wine yeast is S. Ellipsoideus.