KR20200075365A - Manufacturing apparatus and manufacturing methos for liquid fertilizer - Google Patents

Abstract

The present invention relates to an apparatus for preparing a liquid fertilizer and a method for preparing a liquid fertilizer by using the same, which uses an ultrasonic extraction method to prepare a liquid fertilizer with the addition of amino acids extracted from Sargassum horneri (Turner) C. Agardh, so as to utilize non-edible algae, which has become a new contaminant, thereby increasing the enlargement and yield of fruits, and which also uses a two-stage fermentation device to shorten a fermentation period and thus increase fermentation efficiency while reducing the consumption of EM active liquid. Accordingly, the present invention is configured to include: a culture tank for preparing EM active liquid by adding aged seawater; a foreign material dropper for removing impurities mixed in the received fish by-products; a sorter for selecting fish by-products discharged from the foreign material dropper according to quality standards; a grinder for pulverizing the fish by-products input from the sorter; a first fermentation device for primarily fermenting the pulverized fish by-products; a transfer pump for transferring the fermented product discharged from the first fermentation device; a second fermentation device including an impeller with a pH sensor for fermenting the mixture transferred by the transfer pump; a reservoir installed at an upper portion of the second fermentation device for storing an amino acid solution of Sargassum horneri (Turner) C. Agardh; a supply pipe configured to connect the second fermentation device and the reservoir for transferring the amino acid solution of Sargassum horneri (Turner) C. Agardh; a filter for removing solids from the fermentation broth discharged from the second fermentation device; and a packaging machine for packaging liquid fertilizer discharged from the filter.

Description

Liquid fertilizer manufacturing apparatus and liquid fertilizer manufacturing method using the same{MANUFACTURING APPARATUS AND MANUFACTURING METHOS FOR LIQUID FERTILIZER}

This invention can increase the fatness and yield of fruits by using non-edible algae, which is a new contaminant, by adding liquid extracted by adding amino acids extracted from hoejaengjaban using ultrasonic extraction method. It relates to a liquid fertilizer manufacturing apparatus and a liquid fertilizer manufacturing method using the same, which can increase the fermentation efficiency by shortening the fermentation period while reducing consumption of the EM active liquid by use.

The quality of the fruit depends on the environment, cultivation technology and nutritional status. These factors affect the composition of nutrients in the fruit by interacting rather than acting independently, and further affect the quality of the fruit. Among them, the degree of fruit fatness, yield, coloration, and sugar content are important quality indicators that determine the price of the fruit. In particular, the sugar content of the fruit depends on the soil chemical condition of the cultivated soil, fertilizer amount, fertilization method and fertilization time.

The amino acid extraction method, which has been used to manufacture conventional fertilizers, is a waste of amino acids produced by acid decomposition at strong acids and high temperatures, and may induce soil acidification and crop damage by introducing residual hydrochloric acid and heavy metals.

EM (Effective Microoganism) is an abbreviation of Effective Microorganisms. It is a combination of and cultured dozens of microorganisms beneficial to humans among many microorganisms existing in nature. In general, yeast, lactic acid bacteria, and photosynthetic bacteria are the main species constituting EM, and in addition, actinomycetes, filamentous fungi, and archaea are present. It can be said that the effect of EM is the antioxidant power of the fermentation product created by the complex coexistence of these bacteria. EM is a complex of useful microorganisms that promote fermentation. Therefore, by using this property well, it is possible to improve soil and help grow crops. EM with this characteristic can be used not only in agriculture, but also in all areas of the environment, livestock, and daily life.

In recent years, a large number of non-edible seaweeds such as hoe-hats, sea bream, etc. have been generated on the coast to damage the coastal landscape, as well as wind up on the ship's screws, causing damage to fishing and fishing, and attaching to the fish farm nets, causing damage to facilities and farming. It is causing damage such as loss. To solve this problem, a lot of labor was put into collecting and transporting non-edible seaweeds, but due to the inability to secure suitable consumption measures for the collected non-edible seaweeds, a secondary problem that caused odors during storage occurred and some farmers in coastal areas Only the people are using it on a small scale.

Utility Model Registration No. 20-0137056

The present invention is to solve the above problems, by adding an amino acid extracted from hoesaengjaban using ultrasonic extraction method to produce a liquid fertilizer, a liquid fertilizer manufacturing apparatus that can utilize a non-edible algae which is a new contamination factor and It is to provide a liquid fertilizer manufacturing method using the same.

Another object of the present invention is to provide a liquid fertilizer manufacturing apparatus and a liquid fertilizer manufacturing method using the same, which can increase fermentation efficiency by shortening the fermentation period while reducing the consumption of EM active liquid by using a two-stage fermentation apparatus.

As a means for achieving the above object, the configuration of the present invention includes a culture tank for preparing EM active liquid by adding aged seawater, a debris eliminator to remove impurities mixed with fish byproducts, and discharged from the debris eliminator described above. A sorting machine for sorting fish by-products according to quality standards, a grinder for crushing fish by-products input from the above-mentioned sorting machine, a first fermentation device for primary fermentation of the crushed fish by-products, and the first fermentation device described above A second fermentation device for fermenting the mixture transferred to the above-described transfer pump, including a transfer pump for transporting the fermentation product discharged from the impeller equipped with a pH sensor, and the second fermentation device installed above, A storage tank for storing the amino acid solution of the mother and child, a supply pipe for connecting the above-described second fermentation device and the storage tank and transferring the amino acid solution of the hoejajangjaban, and a filter for removing solids of the fermentation liquid discharged from the second fermentation device, It is preferable to include a packaging machine for packaging the liquid fertilizer discharged from the filter.

In the configuration of the present invention, the first fermentation apparatus is a tray sized to contain the pulverized fish by-product, and is installed on the tray, and a plurality of protrusions are formed on the surface to spread fish by-products thinly and uniformly. It is preferable to include a roller, a nozzle installed on the tray above to spray the EM active liquid with fine particles, and infrared illumination to promote fermentation of the mixture contained in the tray.

In the configuration of the present invention, the second fermentation device is installed in the drum body, the drum body and the impeller equipped with a pH sensor, the drum body is installed on the upper part and the above supply pipe can be inserted A cover plate having a hole, an intake duct for supplying air to the drum body, a low-temperature dehumidifying dryer for drying air supplied to the intake duct, and for discharging air from the drum body It is preferable to include an exhaust duct and a dust collecting facility for removing dust from the gas discharged from the exhaust duct.

As a means for achieving the above object, the composition of the manufacturing method of the present invention comprises the steps of preparing EM active liquid by mixing 100 liters of EM stock solution, 100 liters of molasses, and 5 tons of mature seawater, The step of preparing the amino acid powder of raw imitation ban, the step of removing the foreign matter for 30~35 minutes at a rotation speed of 350 rpm by putting the fish by-products put into the foreign matter eliminator, and the color and smell of the fish by-products discharged from the foreign matter eliminator. The step of sorting according to the standard, the step of crushing by introducing the selected fish by-product into a grinder, the step of applying the above-mentioned pulverized fish by-product to a tray using a roller, and applying the above-described coating using a nozzle The step of spraying the EM by-product with fine particles in fish by-products, the step of compacting with a roller so that the above-mentioned fish by-products and EM-activation solution are uniformly mixed, and when the above compaction is completed, irradiate infrared rays in the wavelength range of 2-50 μm. The primary fermentation for ~25 minutes, the primary fermentation product is transferred to the second fermentation device using a transfer pump, and the second fermentation device is for 2 to 3 hours at 40-60°C. The second fermentation step, the step of adjusting the pH of the above-mentioned secondary fermentation product by adding an aqueous solution of hoesan imijaban, and when the pH of the above-mentioned fermentation tank is stabilized, filtering the above-mentioned secondary fermentation product to extract liquid fertilizer And, it is preferable to include the step of packaging the liquid fertilizer described above.

The composition of the manufacturing method of the present invention, the step of preparing the above-mentioned EM active liquid, based on 100 parts by weight of lava seawater, and 5-10 parts by weight of Korea is added, aged at 45-60° C. for 12 hours, and the salt concentration is 0.85~ It is preferable to use aged seawater desalted to 0.90%.

The composition of the manufacturing method of the present invention comprises the steps of preparing the amino acid powder of the above-mentioned hoejajangjaban, crushing the hoejaejajangban with a grinder, and adding 1L of 70% ethanol per 20g of the crushed hoejajangjaban to 15~ If the extraction comprises the steps of treating and extracting the ultrasonic waves at a frequency of 40-50 kHz for 20 minutes, cooling to room temperature after the above extraction is completed, and drying the filtrate obtained by filtering under reduced pressure. desirable.

The composition of the production method of the present invention, the step of adjusting the above-described pH, 20% hoesaengjaban aqueous solution is used, it is preferable to drop the secondary fermentation until the pH is 7.5.

The liquid fertilizer produced by the present invention can be applied to actual farming, and by using the amino acid extracted from hoesaengjaban using the ultrasonic extraction method, the liquid fertilizer is produced to utilize the non-edible algae, which is a new contaminant, to increase the number of fruits. The yield can be increased, and by using a two-stage fermentation device, the consumption of EM active liquid can be reduced while the fermentation period can be shortened to increase fermentation efficiency.

1 is a block diagram of a liquid fertilizer manufacturing apparatus according to the present invention.
2 is a block diagram of a first fermentation apparatus according to the present invention.
3 is a configuration diagram of a second fermentation apparatus according to the present invention.
4 is a flow chart of a method for manufacturing a liquid fertilizer according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to describe in detail that a person skilled in the art to which the present invention pertains can easily implement the present invention. Other objects, including operational objects, effects, effects, and operational advantages will be more apparent from the description of the preferred embodiment.

For reference, the embodiments disclosed herein are only selected and presented as the most preferred embodiments to help those skilled in the art from among various practical examples, and the technical spirit of the present invention is limited or limited only by the presented embodiments. No, various changes, additions, and modifications including equivalents or substitutes are possible without departing from the technical spirit of the present invention.

In addition, the terms or words used in the specification and claims are defined on the principle that the inventor can appropriately define the concept of terms in order to best describe his or her invention. It should not be interpreted as being limited only to a dictionary meaning, but should be interpreted as a meaning and a concept consistent with the technical idea of the present invention. As an example, a singular expression includes a plurality of expressions unless the context clearly indicates otherwise, and a direction expression is set based on a location expressed on the drawing for convenience of explanation, and is “connected” or “connected” The expression “includes” includes not only direct connection or connection, but also connection or connection through other components in the middle.

1 is a configuration diagram of a liquid fertilizer manufacturing apparatus according to the present invention, FIG. 2 is a configuration diagram of a first fermentation apparatus according to the present invention, and FIG. 3 is a configuration diagram of a second fermentation apparatus according to the present invention.

1 to 3, the composition of the liquid fertilizer production apparatus according to the present invention is to remove the impurities mixed in the fish tank by-product and the culture tank (1) for producing EM active liquid by adding aged seawater A foreign substance eliminator (2), a sorter (3) for sorting fish by-products discharged from the foreign substance eliminator according to quality standards, and a grinder (4) for crushing fish by-products inputted from the sorter, and It includes a first fermentation device (5) for primary fermentation of a crushed fish by-product, a transfer pump (6) for transferring the fermentation product discharged from the first fermentation device, and an impeller equipped with a pH sensor. A second fermentation apparatus (7) for fermenting the mixture transferred to one transfer pump, a storage tank (8) installed above the second fermentation apparatus and storing an amino acid solution of hoesanjapan, and the second fermentation apparatus described above A supply pipe (9) for connecting the storage tank and transferring the amino acid solution of the hoejaengjabanban, a filter (10) for removing solids of the fermentation liquid discharged from the second fermentation apparatus, and a liquid fertilizer discharged from the filter It is preferable to include a packaging machine (11).

The first fermentation device 5, the tray 50 of the size containing the above-mentioned pulverized fish by-products, and is installed on the above tray, a plurality of protrusions are formed on the surface, and the fish by-products are thinly and uniformly stretched It comprises a roller (51), a nozzle (52) installed on the top of the tray to spray the EM active liquid as fine particles, and an infrared light (53) to promote fermentation of the mixture contained in the tray.

The above-described infrared light 53 includes a plurality of infrared light emitting diodes (LEDs) that emit light in the infrared region and disperses infrared light using milky glass. Dispersed infrared light is suitable for the purpose of promoting fermentation because it has a deep thermal penetration and can radiate in a wide range.

The above-described second fermentation apparatus 7 is installed on the drum body 70, the drum body, the impeller 71 provided with a pH sensor 711, and the drum body, and is installed above A cover plate 72 having a hole through which a supply pipe can be inserted, an intake duct 73 for supplying air to the drum body described above, and a low temperature dehumidifying dryer for drying air supplied to the intake duct described above It comprises 74, an exhaust duct 75 for discharging air from the drum body, and a dust collecting facility 76 for removing dust from the gas discharged from the exhaust duct.

The drum body 70 may be connected to a separate motor unit (not shown) to generate rotational power.

4 is a flowchart of a method for manufacturing a liquid fertilizer according to the present invention.

As shown in Figure 4, the composition of the liquid fertilizer manufacturing method according to the present invention, a step of preparing EM active liquid by mixing 100 liters of EM stock solution, 100 liters of molasses, and 5 tons of aged seawater (S10), (S20) to prepare the amino acid powder of hoesaengjabanban by ultrasonic treatment, and the step of removing foreign substances for 30 to 35 minutes at a rotation speed of 350 rpm by putting the fish byproducts put into the foreign matter elimination machine (S30). The step of separating the fish by-products discharged from the eliminator according to color and odor standards (S40), and the step of introducing the above-mentioned selected fish by-products into a grinder (S50), and rolling the above-mentioned crushed fish by-products into rollers. Using the step of applying to the tray (S60), and spraying the EM active liquid as fine particles onto the coated fish by-products using a nozzle (S70), and the above-mentioned fish by-products and EM active liquid to be uniformly mixed roller Compacting with (S80), and when the above-mentioned compacting is completed, the primary fermentation is performed for 20 to 25 minutes by irradiating infrared rays having a wavelength range of 2 to 50 μm (S90), and the transfer pump is transferred to the primary fermentation product. Transfer to the second fermentation apparatus by using (S100), and the second fermentation for 2 to 3 hours at 40 ~ 60 ℃ in the above-described second fermentation apparatus (S110) and, by introducing the aqueous solution of hoesaengjapan Adjusting the pH of one secondary fermentation (S120), and extracting the liquid fertilizer by filtering the secondary fermentation product when the pH of the fermentation tank is stabilized (S130), and packaging the liquid fertilizer It comprises a step (S140).

The step of preparing the above-mentioned EM active liquid, based on 100 parts by weight of lava seawater, is added 5-10 parts by weight of Korea, aged at 45-60° C. for 12 hours, and using denatured seawater with a salt concentration of 0.85 to 0.90%. do.

The above-mentioned Skorea is a resource composed of a mixture of porous volcanic sedimentary rocks and their broken volcanic sand, volcanic ash and volcanic coal. The amount of Korea required for the production of aged seawater is less than 100g/L and can be reused.

The aged seawater described above contains not only essential minerals than lava seawater and deep water, but also contains a large amount of general useful mineral components such as iron, manganese, zinc, and molybdenum.

The step of preparing the amino acid powder of the above-mentioned hoejaengjaban is a step of pulverizing the hoejaejajangban with a grinder, and 1L of 70% ethanol per 20g of the above-described crushed hoejajangjaban is applied at a frequency of 40-50kHz for 15-20 minutes. It comprises a step of extracting by treating, and after the extraction is complete, cooling to room temperature, and then filtering under reduced pressure, and drying the filtrate obtained by filtering under reduced pressure.

The above-mentioned hoesaengjaban is a marine algae with a mother-of-pearl and is widely distributed in domestic and overseas East Asian regions. Seaweed contains a large amount of minerals and plant growth-promoting hormones such as auxin and cytokinin.

In the step (S90) of adjusting the above-described pH, the pH is checked through the pH sensor 711 in real time according to the supply amount of the aqueous solution of 20% Hoesengjabanban, and it is operated until the stabilized pH becomes 7.5. When fertilizing by preparing a strong alkaline liquid fertilizer having a pH exceeding 7.5 by adding the above 20% hoesin amethyst aqueous solution excessively, it may cause environmental pollution by rapidly changing the pH of the soil and water quality of the plantation.

By adjusting the pH in this way, the fermentation period of the fermentation product can be shortened and the possibility of propagation of harmful bacteria or odors that can degrade the quality can be removed.

(Experimental Example 1)

Yield and amino nitrogen measurement tests were performed in order to confirm the optimum sonication conditions in the amino acid extraction method of the above-mentioned Hoeseng amoeba.

First, 1 g of 70% ethanol was added to 5 g of crushed hoejajangjaban, and extracted according to each condition with an ultrasonic treatment device (Mars X, CEM Co., USA). After filtration under reduced pressure, the extract was concentrated under reduced pressure at 45° C. or lower to remove water, and then transferred to a separatory funnel to remove the fat layer by adding ether, and the separated aqueous layer was dried at 45° C. or lower to completely remove the solvent to obtain a hoejapanjaban powder.

The yield (%) was calculated as (weight of the obtained hoejapanjaban powder)/(weight of the hoejajangjapan used for extraction)×100.

Amino nitrogen was tested by titration (Formol titration) and the method is as follows. After adding 100 ml of distilled water to 2 g of the obtained hoesin azaban powder, 0.1 N sodium hydroxide solution was added to adjust the pH to 8.4, 20 ml of neutral formalin solution was added, and titration was again performed with 0.1 N sodium hydroxide solution until pH 8.4. Then, the amino nitrogen content was obtained according to the following equation.

Amino nitrogen (%) = ((A-B)*1.4*F)/S*100

A: A proper amount of 0.1 N NaOH solution (ml)

B: blank amount of 0.1 N NaOH solution (ml)

F: Titer of 0.1 N NaOH solution

S: Sample amount (g)

The results are shown in Table 1 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Ultrasonic frequency
(kHz) 40 50 30 60 yield(%) 17.2 17.0 17.2 11.5 Amino nitrogen
(mg%) 1002.0±0.3 997.1±9.9 811.0±3.4 984.0±2.4

As in the above results, in the case of Comparative Example 1, the amino nitrogen content was the lowest, which is judged to be because the ultrasonic intensity is strong, but the precision is weak. In the case of Comparative Example 2, the yield of the obtained powder was the lowest, which is judged to be because the strength of ultrasonic waves was weak. On the other hand, Example 1 and Example 2 showed excellent results in both yield and amino nitrogen content. Therefore, it is preferable to extract amino acids from the hoejajangjaban under the conditions of ultrasonic treatment of the present invention.

(Experimental Example 2)

Prepare liquid fertilizers (Example 1, Example 2, Comparative Example 3, Comparative Example 4, Commercial Product 1) to confirm the medicinal effect of the liquid fertilizer prepared by the above-described manufacturing method, and fertilize them to grow lettuce and 4 Growth status was observed for a week. The results are shown in Table 2 below.

Example 1 Example 2 Comparative Example 3 Comparative Example 4 Commercial Products 1 Aqueous solution
Addition or not ○ ○ × ○ - Fermentation
Way Primary ○ ○ ○ × - Secondary ○ ○ ○ ○ - Live weight (g) 1 week 12.1 11.8 10.1 10.4 9.0 2 weeks 45.2 45.1 35.1 37.4 22.0 3 weeks 86.7 82.4 75.9 72.0 50.9 4 weeks 132.2 128.8 97.1 94.1 80.4

As shown in the above results, in the case of Example 1 and Example 2, which were prepared by adding the aqueous solution of hoesaengjabanban and performing both the first fermentation step and the second fermentation step, the size of lettuce and the highest in vivo weight were the highest. On the other hand, in Comparative Example 3, in which only the aqueous solution of hoesaengjaban was not added, and in Comparative Example 4 in which only the first fermentation step was omitted, the size of lettuce was similar to that of the example, but the thickness of the side was thin, indicating a lower weight than the example. . In the case of the commercial product 1 without special additives, both the size of the lettuce and the weight in the body showed the lowest value. Therefore, the liquid fertilizer produced by this invention can shorten the fermentation period and promote the rooting and growth of crops.

1: Culture tank 2: Foreign material eliminator
3: sorter 4: grinder
5: first fermentation device 50: tray
51: roller 52: nozzle
53: infrared light 6: transfer pump
7: Second fermentation device 70: Drum body
71: impeller 711: pH detector
72: cover plate 73: intake duct
74: low temperature dehumidifying dryer 75: exhaust duct
76: dust collection facility 8: storage tank
9: Supply pipe 10: Filter
11: Packing machine

Claims (7)

A culture tank for producing EM active liquid by adding aged seawater,
A foreign substance eliminator that removes impurities mixed with the fish by-products,
A sorting machine for sorting fish by-products discharged from the foreign substance eliminator according to quality standards,
Crusher for crushing fish by-products input from the above-mentioned sorting machine,
A first fermentation device for primary fermentation of the crushed fish by-products,
Transfer pump for transferring the fermentation product discharged from the first fermentation device,
A second fermentation apparatus including an impeller equipped with a pH sensor and fermenting the mixture transferred to the above-described transfer pump,
Is installed on the second fermentation device and the storage tank for storing the amino acid solution of hoesaengjapan,
Supply pipe for connecting the above-described second fermentation device and the storage tank and transferring the amino acid solution of the hoejajangjapan,
Filter for removing the solids of the fermentation broth discharged from the second fermentation apparatus,
Liquid fertilizer manufacturing apparatus comprising a packaging machine for packaging the liquid fertilizer discharged from the filter. According to claim 1,
The first fermentation device described above,
A tray sized to contain the crushed fish by-products,
It is installed on the upper tray and a plurality of protrusions are formed on the surface, and a roller that spreads fish by-products thinly and uniformly,
A nozzle that is installed on the tray above to spray the EM active liquid as fine particles,
Liquid fertilizer manufacturing apparatus comprising an infrared light for promoting the fermentation of the mixture contained in the tray. According to claim 1,
The second fermentation device described above,
The drum body,
The impeller installed in the drum body and equipped with a pH sensor,
And the cover plate is installed on the upper drum body and a hole through which the supply pipe can be inserted,
An intake duct for supplying air to the drum body,
Low temperature dehumidifying dryer for drying the air supplied to the intake duct described above,
An exhaust duct for discharging air from the drum body,
Liquid fertilizer manufacturing apparatus comprising a dust collecting facility for removing the dust of the gas discharged from the exhaust duct. Preparing EM active liquid by mixing 100 liters of EM stock solution, 100 liters of molasses, and 5 tons of aged seawater;
Preparing a amino acid powder of hoejaengjaban by ultrasonic treatment of hoejajangjaban,
Removing the foreign substances for 30 to 35 minutes at a rotation speed of 350 rpm by putting the received fish by-products into the foreign substance eliminator;
Separating fish by-products discharged from the foreign substance eliminator according to color and odor standards;
And the step of crushing by introducing the selected fish by-products into a grinder,
Applying the crushed fish by-products to the tray using a roller;
Spraying the above-mentioned coated fish by-products with EM active liquid as fine particles using a nozzle;
Compacting with a roller to uniformly mix the above-mentioned fish by-product and EM active liquid,
When the above-mentioned chopper is completed, the primary fermentation is performed for 20 to 25 minutes by irradiating infrared rays having a wavelength range of 2 to 50 μm,
Transferring the primary fermentation product to the second fermentation device using a transfer pump;
Second fermentation for 2 to 3 hours at 40 ~ 60 ℃ in the above-described second fermentation apparatus,
Adjusting the pH of the above-mentioned secondary fermentation product by adding an aqueous solution of hoesaeng azamoban,
When the pH of the fermentation tank is stabilized, filtering the secondary fermentation product to extract liquid fertilizer,
Liquid fertilizer manufacturing method comprising the step of packaging the liquid fertilizer. The method of claim 4,
Preparing the above-mentioned EM active liquid,
Liquid fertilizer manufacturing method, characterized in that using 5-10 parts by weight of Korea, aged at 45-60°C for 12 hours based on 100 parts by weight of lava seawater, and using aged seawater desalted to a salt concentration of 0.85 to 0.90%. The method of claim 4,
The step of preparing the above-mentioned amino acid powder of hoesaengjapan,
The step of crushing the hoesaengjaban with a grinder,
Adding 1L of 70% ethanol per 20g of the above-ground crushed hoejajangjaban and extracting by treating with ultrasonic waves at a frequency of 40-50kHz for 15-20 minutes;
After the above extraction is completed, after cooling to room temperature and filtering under reduced pressure,
And drying the filtrate obtained by filtration under reduced pressure. The method of claim 4,
Adjusting the above-described pH,
A method of manufacturing a liquid fertilizer characterized by using a 20% hoesaengjaban aqueous solution and dropping it until the pH of the secondary fermentation reaches 7.5.

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