Q&As about Revos concentration system

Q: How can you guarantee the water quality whilst reconstituting the beer concentrate in a pub?  

A: Revos draft dispense systems require the installation of a 5-micron carbon filter on the feed water line. The filter removes odours and particulates. For many local water supplies, this level of treatment is sufficient. However, if the water hardness or total dissolved solids in the main water supply is high, the installation of an under-the-counter ion exchange unit and/or reverse osmosis water purification unit to feed the draft dispense system is recommended.  


Q: What are the ATEX considerations with beer at 22%+ ABV?  

A: ATEX requirements (relevant for European installations) are analyzed on a case-by-case basis. Given liquids are fully enclosed in the Revos concentration system, ATEX-rated components are generally not required, provided the concentrates are 24% ABV or less.  


Q: Is it possible to convert the dispense system to 50 Hz?  

A: There is no need to convert the Revos draft dispense system. It is available in both 50 Hz and 60 Hz frequencies.  


Q: How do you measure alcohol concentration in the Revos process?  

A: This is accomplished by measuring the inline density and refractive index and combining these measurements in a proprietary model to calculate the inline alcohol concentration.  


Q: What is the running cycle between Cleaning-in-Place (CIP) for the concentration module?  

A: The concentration module undergoes caustic cleaning at 11.5 pH on a weekly or biweekly basis. This process takes about four hours. Short 30-minute warm deaerated water flushes are also used on a daily or every-other-day basis for membrane regeneration.  


Q: What is the typical timeframe for membrane replacement?  

A:  The recommended interval for membrane replacement is 9 to 12 months, depending primarily on the frequency of CIP.  


Q:  Is there a real business case that you can share? Can you provide a complete overview of the savings achieved?  

A: We do not have a business case that we can share publicly at present. A representative all-in number for concentration with Revos, including amortized capital costs, is about €1-2 per hl (at sales gravity), with larger installations achieving the lower end of this cost range. Savings are proportional to transport costs. For example, if transport costs are €10/hl for bulk transport, Revos may cut that down by €6.6/hl. For draft dispense applications, savings are often larger. For instance, transport costs may be €20/hl without a concentrate-based approach; a concentrate-based approach may reduce those costs by €16/hl or 80%. The percentage transport savings are typically larger for draft dispense applications because bulk transport is often already done at high gravity.  


Q: Is it possible to create instantaneously more beer brands from the same keg (mother beer) by playing with different blending ratios?  

A: Yes, this is possible but may require some software upgrades to the draft dispense technology, depending on the complexity of what is required.  


Q: Is concentrated product filled into kegs or bag-in-boxes (BIBs) using Alfa Laval Astepo as seen on the slide during the webinar?  

A: Revos draft dispense system can handle kegs or BIBs. From 2023, we are considering offering an Alfa Laval BIB filling solution. For 2021 and 2022, the focus will be on kegs as brewers are already equipped with kegs and keg-filling machines.  


Q: What is the maximum concentration that can be achieved? Is it possible to go up to 70% for other beverages by adding an additional membrane?  

A: The maximum concentration for beer concentration is 24% ABV. We are currently testing the technology to allow for ethanol concentration up to 50% ABV. 


Q: What is the smallest capacity? 

A: The smallest throughput for a Revos unit is 6 hl/h. See the presentation for details. 


Q: Regarding the Revos draft system: Is ultraviolet (UV) treatment necessary on the water line since the water source is food grade and the blended beer is to be consumed immediately after blending?  

A: UV is not essential, but shelf-life testing shows that it can delay microbial growth downstream of the blending of water and concentrate. Note that the UV light is included as part of the Revos draft dispense technology.  


Q: What kind of water is required for reconstitution? Is there a loss of brewing salts?  

A: To reconstitute Revos concentrates, Alfa Laval recommends the use of low TDS water. Low TDS water is water that contains between one and 100 milligrams per litre (mg/L) of total dissolved solids (TDS), like that used by brewers to de-brew high gravity beer. Because Revos only removes water from beer, there is no loss of brewing salts. All brewing salts are retained in the concentrate. 


Q: How many people are required to operate the Revos concentration systems?  

A: The Revos concentration systems are fully automated. One person is required to replace the membranes after 9 to 12 months.  


Q: How many people are required to install the Revos concentration systems?  

A: One.  


Q: I have no experience with concentrating beer or using concentrated beer. Is such a beer completely free of CO2 after undergoing reverse osmosis? What are the procedures to reconstitute the beer with CO2? 

A: Typically, there is natural carbonation in beer that is fed to Revos. Revos membranes are permeable to gas, so the Revos concentrate and permeate will have the same level of carbonation as the feed. CO2 is added during reconstitution of the concentrate just as it is when de-brewing high gravity beer. Alfa Laval has Carboblend and Alfadose technology available for this reconstitution. 


Q: Can multiple products be served from the same draft dispense system?  

A: Yes. Revos draft cellar can serve up to four products. Revos draft mobile can serve up to two products.  


Q: Do you have OPEX costs for Revos, or even better Revos OPEX vs OPEX for competitors’ technologies? 

A: For Revos, OPEX costs typically are between €0.5/hl and €1/hl. Alfa Laval does not have precise figures on competitors’ technologies other than to emphasize that there is no evaporation or freezing with Revos, which is a significant benefit for energy requirements. 


Q: What is the energy consumption of the system? 

A: The energy consumption is about 1 kWh/hl. For details, see the presentation. 


Q: Do you have an indicative cost of installation, for instance, for the Revo 30? 

A: Quotations can be provided upon request. 


Q: What is the readiness level or maturity of this technology? 

A: Revos technology is ready for commercial deployment. 


Q: Are there any problems with foam created by system? If so, how do you address it?  

A: Foaming in the system is avoided by maintaining positive pressure for feed beer supply.  


Q: Is the Revos draft dispense system available now? What is the approximate cost to install a unit? 

A: Revos draft dispense test units are now available for rental and commercial-scale prototypes are available for order. 


Q: How long does it takes to concentrate to the max? 

A: The concentration process is continuous and has a start-up time of about 30-60 minutes. 


Q: Draft dispense seems like it requires a lot of changes to the supply chain. Where does Revos draft dispense make the most sense? 

A: Revos draft dispense is best suited for brewers who manage or own draft equipment, or brewers who have close relationships with venues dispensing draft beer. 


Q: What is the rental price for the 6-hl pilot plant? 

A: Quotations can be provided upon request. 


Q: In general, what peripherals are necessary?  

A: Revos modules require warm (35°C) water for Cleaning-in-Placer, deaerated water for flushing, and electricity and compressed air for valve operation. 


Q: Is this the concentration unit (conceptually) capable of being used as part of a mobile operation. 

A: Yes. 


Q: Are dimensions of the Revos system conducive to skid mounting or truck mounting? 

A: A skid-mounted Revos system can also be mounted on a truck. Dimensions are provided in the presentation.