Pasteurization Units for Tunnel Pastuerizer

[Apld_Bottling]

Hello All,

I'm trying to get a consensus and literature on PU requirements for beer in hot climates with bad refrigeration.

Any comments?

Darryl
Applied Bottling
sales@applied-bottling.com
250-220-6284

[Larry Doyle]

First, assume no refrigeration. That is why beer is pasteurized.
PU (pasteurization unit) requirements vary based on several factors. Here are some of them:
-How "dirty" is your beer, microbiologically speaking? A higher micro load will require higher PUs.
-More PUs are required as alcohol content is reduced. Normal alcohol beers in the US get around 8-12 PUs while some lower alcohol products get around 18-25. A no alcohol beer could require up to 50 PUs.
-Any reduction in bittering units could warrant an increase in PUs as hops have a biocidal effect.
-PU requirements increase as the growth medium or "food" increases. I heard of a brewery in the Dominican Republic that was pasteurizing at 50 PUs, presumably for this reason.

You will need to get a good handle on the micro quality of your beer and the PUs needed to eliminate micro counts.

[Apld_Bottling]

Makes sense ...any idea where I can find literature on pasteurizer design ... max rate of heating, at what temperatures to switch to a new zone, rate of heat absorption in bottle ... same for cooling ... calculating PU's for changing temperatures ... all that interesting stuff ...

Thanks - Darryl

[Larry Doyle]

Darryl;
Your best bet will be to contact pasteurizer manufacturers for general info. Ones I know of are Barry- Weymiller in St. Louis and Sander Hansen in Europe.
Some thoughts:
-you will need to get your beer temp to 140-145 to generate the PUs you will need. See if you can get a lethal rate chart which shows PU accumulation vs. time and temperature. You will also need to cool the beer down to 80 degrees or less to prevent excessive oxidation.
-you need to control maximum beer temperature. Too hot hurts taste. For normal beer, don't go above 145 degrees. For high PU beer dont go above 148 degrees.
- If you are serious about this you will need a "PU computer." This is a device that you run through the pasteurizer that measures beer and spray temps and times in the various zones and provides charts of the pasteurization curves.

[matt]

Not much help, but the EBC has a pateurisation good practice hand book, but last I looked, it was out of print. (need a copy myself)

A little extra on pasteurising.
A PU is not just a PU , or 68 degrees C for 60 seconds and 60 degrees C for ten minutes will give you about the same amount of PUs (approx. 10) but the overall effect is, like mentioned in previous replies, dependent on the product, micro loading of the product and what micros you are trying to destroy, and how much.
Manufactuers would be reluctant to tell you, "you need X amount of PUs" for the above reasons. You will need to verify your pasteurisation regime product by product.
There are also different types of pasteurisers and methods, Flash, tunnel, batch, HTST, LTLT, UHT. Not pasteurising but also sterile filtration is an option. Which one will work best for your situation?

More questions then answers, but not a simple question to answer without knowing all of the above.
Try a search here, as I believe this topic has been discussed before.

[dick murton]

If I remember corectly, the Sander Hansen (KHS / Steinecker) site has details of their control system with an outline of the temperatures through the passie.

There was definitely another discussion about this, as I for for one contributed, but have to say I can't remember what the original topic description was.

One of the best in pasteuriser test pieces is made by Redpost, but it willset you back a few thousand. I guess if you google this you will find more details. There are presumable other cheaper versions. I know I used a thermograph, which drew traces on a circular chart - don't know if these are still available

[matt]

Our Tunnel pasteuriser has a circular chart recorder that records the temperature of the pastuerisation zone water.

But we also use an Ebro Data logger Which is placed on the bottle with the probe located in the "Cold" zone of the bottle. This travels through the pasteuriser recording temperature every 60 seconds. You can program different parameters, or other models record pressure as well as temperature.
Not cheap and should be calibrated often(yearly) but worth the peace of mind.

Depending on many variables, the setpoint temperature of the pateuriser can vary greatly from the temperature of the product.

[beertje46]

Here is the Lethal Rate Curve from Beer Packaging - MBAA 1982


Whoops! The file size exceeds forum limits x 2.

PM me with an e-mail address if you'd like a copy.