Beer cooling: dry, wet or python cooler?

An in-line beer cooler only chills the beer as it is being tapped: it flows through cooling coils and comes out of the tap cold – even if the keg itself is not chilled. There are three types.

How the beer gets cold into the glass

1 · CO2 and regulatorCarbon dioxide pushes the beer out of the keg.

2 · Keg with couplerThe keg does not need to be chilled.

3 · In-line coolerchills the beer as it flows through.

4 · TapThe beer comes cold into the glass.

If keg and bar are far apart, a python cooler also keeps the line cold up to the tap.

The types

Dry cooler

Inside the unit a refrigeration machine with a compressor chills a solid cooling block. Stainless steel cooling coils run through it: the beer flows through them and gives off its heat to the block. You set the temperature on the thermostat. No water bath is needed, the unit is ready for use within a few minutes – and single-line units weigh just 14.5 to 34 kg. Ideal for parties, mobile use and the bar.

Wet cooler

The wet cooler works with a water tank in which the refrigeration machine builds up an ice bank; the beer coils lie in the ice water. The ice bank is a cold reserve – a unit with 100 l/h has 14 kg of ice. When a lot is tapped, it melts and absorbs the peaks. So the wet cooler delivers consistently cold beer for hours, even at high dispensing volumes – for catering, festival tents and continuous operation. Many models also have built-in python cooling for long line runs. Before use, fill the tank with water to just below the overflow; the unit is ready once the ice bank has built up.

Python cooler

The python cooler pumps chilled water from its tank (20 or 45 litres) through a companion line (“python”) next to the beer line and back again. This keeps the beer cold right up to the tap even over long distances – for example from the cellar to the bar. Rise height and line length state how high and how far the pump delivers the water, for example 6 m and 20 m or 18 m and 30 m. The cooling line is connected with a 5/8 inch thread.

In-line and python cooler

Combination units chill the beer as it is tapped and also supply a python line – both in one unit.

Comparison at a glance

	Dry cooler	Wet cooler	Python cooler
cools with	solid cooling block	ice bank in a water tank	cold water in the python line
fill with water	no	yes	yes
ready	within a few minutes	once the ice bank has built up	once operating temperature is reached
dispensing capacity (our range)	18–200 l/h	34–200 l/h	– (keeps the line cold)
weight	14.5–87 kg	48–76 kg	27–44 kg
strength	light, quickly ready, mobile	cold reserve for continuous operation	long distances from keg to bar

Which cooler for which use?

Use	Recommendation
Garden party, birthday, club event	dry cooler, single- or 2-line
Large events with many guests	powerful dry cooler or wet cooler
Catering, continuous operation	wet cooler
Keg in the cellar, long distance to the bar	python cooler or in-line and python cooler

Reading the dispensing capacity

The dispensing capacity in litres per hour (l/h) states how much beer the unit chills continuously. For our units it applies to a temperature difference of 10 °C (“at 10 °C TD”) – the beer is cooled by 10 degrees. If the keg is warmer, the cooler has to cool more and manages fewer litres per hour. So keep the keg in the shade if possible.

Capacity	0.25 l glasses	0.3 l glasses	0.5 l glasses
25 l/h	100	approx. 80	50
60 l/h	240	200	120
100 l/h	400	approx. 330	200
200 l/h	800	approx. 670	400

Rule of thumb for planning: guests × glasses per hour × glass size. 100 guests with one 0.3 l glass each per hour need 30 l/h – with a reserve for the rush, a unit with 60 l/h is the safe choice.

What to look out for

Lines: single-line for one beer, 2-line for two beers at the same time, 4-line for a bar with several beers.
Nominal width: NW 7 or NW 10 – to match hoses and tap (see connections & hoses).
Taps: on many units all taps with a 55 mm or longer threaded shank fit – the details are given with each item.
With air compressor: no CO2 needed, but the keg should be empty within one to two days.

Set-up and care

Place the unit on a level, dry and clean surface, ensure good ventilation and do not put anything underneath it.
The ambient temperature should be between +10 and +40 °C.
Clean dust off the condenser about every six months – a dirty condenser is a common reason why a unit runs but no longer cools properly.
Only clean the housing with a damp cloth and a little washing-up liquid, after unplugging the unit. No moisture may get into the unit.
After cleaning the lines, allow enough time for everything to cool down again. How to clean the lines is explained under cleaning your beer tap.

The beer foams? Common causes

Problem	Possible cause	What helps
foams too much	beer too warm, the unit has not yet reached its operating temperature	wait until the unit is cold
	dispensing pressure too high	reduce the pressure on the regulator
	beer contaminated or over-carbonated	connect a fresh keg, clean the system
foams too little	beer too cold	turn the thermostat up
foams too little	dispensing pressure too low	increase the pressure

More about the right pressure under CO2 & pressure regulators. If the unit no longer cools at all, repairs belong in the hands of a refrigeration specialist.

Frequently asked questions

Does the keg have to be chilled?

No, the in-line cooler chills the beer as it is tapped. The warmer the keg, however, the fewer litres per hour it manages – a shady, cool spot helps.

How long before do I need to switch the cooler on?

A dry cooler is ready within a few minutes. A wet cooler takes longer because the ice bank has to build up first – the lead time is stated in the operating manual.

Dry cooler or wet cooler – which is better?

For parties and mobile use the light, quickly ready dry cooler is usually the better choice. When a lot is tapped over a long time, for example in catering or a festival tent, the wet cooler with its ice bank plays to its strengths.

Do I need a CO2 cylinder?

Yes, except for dry coolers with a built-in air compressor. How long a cylinder lasts is explained under CO2 & pressure regulators.

NW 7 or NW 10?

NW 7 is the standard. NW 10 is worthwhile for long line runs or high dispensing capacity. Cooler, hoses and tap must all match the same nominal width.