Regenerative section of a beer flash pasteuriser: how much heat the beer-to-beer plates recover, and how pressure and CO₂ are held across them
Beer-to-beer heat recovery in a flash pasteuriser · 90, 93 or 95 % recovery in published units, what each step does to heater and cooler duty, the pressure regime that keeps CO₂ in solution, and the pasteurisation units it has to deliver around
In a flash pasteuriser, cold unpasteurised beer and hot pasteurised beer pass each other through the first section of the plate pack. Every degree the cold beer picks up there is a degree the heater does not have to supply and a degree the cooler does not have to remove. The same plates are also the one place where pasteurised and unpasteurised beer sit a gasket and a sheet of stainless steel apart, under pressures set to keep carbon dioxide in solution.
The regeneration (heat-recovery) section of flash pasteurisers for beer, beer mixes, cider, hard seltzer and other carbonated drinks: its recovery percentage, the temperatures it hands to the heater and cooler, the pressure regime and booster pump that protect the pasteurised side and prevent outgassing, and its relation to the pasteurisation units set at the holding tube. Milk and dairy regenerators, with their PMO pressure relationships, differential pressure controllers and plate leak tests, are covered on the Regeneration section of a plate pasteuriser page; complete HTST milk pasteurisers on the Continuous-flow (HTST) pasteurisation system page; hot-fill heating coils and holding tubes on the Product heating and holding tube for hot-fill beverages page. Tunnel pasteurisers for filled containers are not covered here.
CNFX editorial research · Sources checked October 13, 2026 · 3 sources
90, 93 or 95 % heat recovery: what each step leaves for the heater and the cooler
Three published figures for beer flash pasteurisers, from two machine builders and a brewing-science presentation:
Editorial calculation, assuming equal flow and heat capacity on both sides, beer entering at 2 °C and pasteurisation at 72 °C (70 K span): at 90 % recovery the cold beer leaves the regeneration section at 2 + 0.90 × 70 = 65 °C and the hot beer at 72 − 63 = 9 °C; at 93 %, 67.1 °C and 6.9 °C; at 95 %, 68.5 °C and 5.5 °C. The heater therefore lifts the beer by 7 K, 4.9 K or 3.5 K. For the 30,000 l/h GEA example, and taking the heat capacity of water (4.19 kJ/kg·K) as an approximation for beer, that is about 244 kW, 171 kW or 122 kW of heating. [2][1]
Editorial note: the trade is plate area, because a higher recovery needs a closer temperature approach between the two beer streams, so more plates in the regeneration section. ESAU & HUEBER offers higher recovery only as an option to its 90 or 93 % standard. [2]
Source
Heat recovery stated
Context given
ESAU & HUEBER CRAFT, SMART and CONTI FLASH
90 or 93 % in the standard versions; higher rates as an option [2]
Beer, fruit drinks and juices with fibres up to 1.2 mm; hot water at 82 °C for heating [2]
GEA ECO-FLASH, example key figures
95 % in a three-stage plate heat exchanger (heat recovery, heating, cooling) [1]
Bright beer with 5.5 g/l CO₂, 30,000 l/h nominal, 2:1 turndown, 70–75 °C pasteurisation range [1]
Brewers Association presentation (A. Speers)
Flash pasteurisation “up to 95% energy efficient” [3]
Beer heated to 70–75 °C and cooled to 5 °C before packaging; energy costs 8–10 times lower than tunnel pasteurisers [3]
Ask for the recovery percentage at your flow and inlet temperature, the outlet temperatures of both streams, and the plate area of the regeneration section on its own.
02
Pasteurised beer at the higher pressure: a booster pump ahead of the heater, a 16 bar operating pressure and no outgassing
ESAU & HUEBER builds its units as re-infection-proof and high-pressure resistant: an integrated booster pump upstream of the reheating section in the heater creates a positive pressure drop, which, the brochure says, “ensures that no pasteurised product leaves the flash pasteuriser at any time during production” (the wording as printed). The plate apparatus and product line are protected by a safety valve that can be lifted pneumatically during cleaning. [2]
GEA lists a high-head feed pump and a booster pump in the pasteurisation module, a consistent pressure regime that prevents outgassing and ensures a positive pressure gradient, mix-proof valves throughout, and an operating pressure of 16 bar in its example for bright beer with 5.5 g/l CO₂. Its utilities include CO₂ at 6–8 bar with at least 99.995 % purity and saturated steam at up to 6 bar overpressure for the hot-water circuit. [1]
Editorial note: in a beer unit the regeneration section therefore carries two pressure jobs at once, keeping the pasteurised side above the unpasteurised side across every plate and keeping both above the pressure at which dissolved CO₂ would break out at the highest temperature reached in that section.
Ask for the pressures on both sides of the regeneration section at its hottest point, the CO₂ content it is designed for, and how the booster pump is interlocked if pressure is lost.
03
The pasteurisation units the system must deliver: about 10 PU for full-strength beer, more than 40 PU for alcohol-free
One pasteurisation unit is the heat applied by holding the product at 60 °C for 1 minute, and the lethality at each temperature is 10^((T − 60)/z); the presentation's table gives 1.393 at 61 °C and 1.941 at 62 °C. It states that full-strength and normal light beers need around 10 PU for a 6-log reduction of the heat-resistant beer spoilers it names (Pediococcus acidilactici or Lactobacillus delbrueckii), extra-light products at 1.8 % alcohol more than 18–20 PU, and non-alcoholic beers below 0.5 % more than 40 PU. It also advises keeping oxygen below 0.3 mg/L and controlling flow or using a surge tank to limit burnt and oxidised flavours. [3]
Editorial calculation: at 72 °C for 30 seconds, PU = 0.5 min × 1.393^(72 − 60) ≈ 26.7 PU, using the lethality step per degree from the table above. [3] GEA gives an adjustable range of 10–100 PU for its example unit; ESAU & HUEBER keeps residence time in the holding tube constant and has the controller set the heating temperature for the selected PU. [1][2] The regeneration section affects that control only through the temperature it delivers to the heater: the closer it brings the beer to pasteurisation temperature, the smaller the correction the heater has to make when the PU set point changes.
State the alcohol content, pH and target PU of each product, and the flow range; check that the heater can reach the highest PU at the lowest regeneration outlet temperature.
04
What to send when specifying the regeneration section of a beer flash pasteuriser
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Products: [beer types; alcohol; CO₂ g/l; fibres or pulp]
Flow: [nominal l/h; turndown]
Temperatures: [inlet; pasteurisation; outlet to filler]
Recovery: [target %; outlet temperatures of both streams]
Pressure: [operating pressure; pasteurised-side margin; booster pump interlock]
PU: [target per product; control method]
Cleaning: [CIP route; safety valve lifting]
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Compiled and source-reviewed by the CNFX editorial team.
Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review
· Page last updated 13 October 2026
Buyer questions
How much heat does a beer flash pasteuriser recover?
Published figures are 90 or 93 % in ESAU & HUEBER standard units, 95 % in a GEA example, and “up to 95%” in a Brewers Association presentation. [2][1][3]
Why is there a booster pump before the heater?
To create a positive pressure difference so pasteurised product is kept at the higher pressure; GEA also cites preventing outgassing of CO₂. [2][1]
How many PU does beer need?
Around 10 PU for full-strength and normal light beers, more than 18–20 PU at 1.8 % alcohol, and more than 40 PU below 0.5 % alcohol, according to the Brewers Association presentation. [3]
What operating pressure does a beer flash pasteuriser run at?
16 bar in GEA's example for bright beer with 5.5 g/l CO₂ at 30,000 l/h. [1]
Sources and what still needs a direct check
Sources checked 2026-10-13. Heat recovery, pressure regime and operating data come from GEA's ECO-FLASH technical data and ESAU & HUEBER's flash pasteuriser brochure; pasteurisation units, required PU and flash-pasteurisation figures from a Brewers Association presentation by Alex Speers.
