Chillers temperatures

hi

i have a cold store used for fresh products.as a statutory requirment we must maintain temperature of chiller between 0 - 4 C

in our case defrosting time for chiller is 30 min every 6 hours during this time temperature reach 8 C

what to do comply any idea.

regards

Hi there, I also deal in fresh products, and maintain the same temperatures.  The requirements do not include defrost time, so you have nothing to worry about. The defrost is a neccessary part of the workings of the chillers. I assume you keep temperature logs or another form of records, I would suggest that you indicate the defrost period on those logs to verify that it was not a temperature anomalie. Also, a written procedure that describes the defrost and the frequecy will help validate your records.

Another exercise would be to determine the core temperature of the products in store during the defrost to determine that they are not being compromised.

I hope this helps :)

As the above poster suggested....I would be verfiying the outer, inner and core temps of products in various spots in the chiller...build up some data and then use this to prove no risk / exemption. :)

Hi asim,

This is real life situation...previously, we do used to have this argument (among warehouse, quality & engineering) especially when the warehouse guys record temp and found "out of spec" especially during defrost period. later we installed temp recorder to know exactly the temp curve behavior. With a simple SOP in place, we managed to get exempted from our FSSC consultant and the food safety team. In this case, the record really helps especially to understand the chilling process.

Exactly as mentioned by two gentlemen above.  :rock: 

i have a manual temp recording and i have data loggers which shows all fluctuations during and after defrosting.on top of that we have lab test to prove that no risk on product safety from chiller defrosting.
but i dont have a procedure for defining the defrosting process i will do that

thanks guys for the help

Hi there, you could consider installing a 100% natural mineral in your chiller/s that lowers ambient temperatures by 2°C and 10°C; increases and stabilises relative humidity to between 80% and 87% (the ideal range); reduces air-borne bacteria by 82%; reduces food spoilage gases by a consistent 79%; and will ensure that temperature recovery (whether defrost or simply opening and closing chiller doors) is reduced by 50%!

Dear asim,

The critical factor is the temperature variation of the product. This is not necessarily the same as yr data-loggers.

The typical measurement procedure for packaged chilled goods in a stable environment does not, AFAIK, require direct contact/breakage of the product/packaging respectively

Rgds / Charles.C.

Hi all,

I have a related question for you wonderful FS gurus.

We are a very small facility which makes a wide range of sandwiches based on customer orders (ie: we can make between 1 - 250 of each flavour of sandwich).

In our production room where we make the packaged sandwiches etc, we have a couple of open fronted chillers that we store various ingredients in, such as RTE meats, cheese, lettuce, sauces etc.  

Currently our procedure is to check the temperature of each chiller twice per day using an infra red thermometer/gun.  Currently the staff do this by aiming it at the interior back wall of the chiller on each shelf.  Obviously this will show that it is out of specification during a defrost cycle.  

I have requested that staff open a food container on each shelf and take the temperature of the food directly, however this doesn't allow for the temperature variations while the food is being taken out of the chiller during use then put back in.

We can't afford a fancy permanent digital monitoring system, but I do occasionally put a datalogger in the chiller to verify the temperatures.

Would anyone have any recommendations of an analogue thermometer that could be placed into some type of medium which would replicate the food core temperatures and not the variable defrost temps?  What medium would work, given that it will be beside food. (In a previous job in a micro lab, I had used sand or glycol as a medium - For food, I was wondering about something like rice which wouldn't be a huge issue if it got knocked over)

The same question applies for our freezers where currently the temperature is read from the digital display on the wall which does not reflect the actual food temperature.

Thanks in advance.

Dear primadeli,

I presume the chiller temperature is in range around 0-8degC as OP. The question sounds similar to the problem of monitoring the product temperature in the chilled section of home refrigerators. But if the product temperatures are varying from say 25degC to near zero then any method for individual items which assumes a system equilbrium is going to be questionable IMO.

The refrigerator scenario was discussed here in some detail a few years back. The preferred system was to add an appropriate closed container/liquid, eg plastic cup/glass of water with an immersed calibrated thermocouple. The point is that the liquid acts as a buffer and smooths out variations due things like opening doors etc. This could be validated as reasonably replicating the refrigerator's actual product temperatures. Might require >1 unit in yr case though depending on temperature variation with location. Someone previously posted a link to a commercially available small package to stick in the refrigerator and allow the temperature to be followed (either externally or self-storing the data, can't remember).
You should be able to find the old thread by doing a search for, eg "refrigerator", unless someone here knows the commercial product. i have used a crude manual version and simply manouevred the thermocouple line through the refrigerator door and outwards although you have to be careful with effects due the TC line interacting with environment. It worked well enough.

By freezing temperatures i presume you mean down to -18degC or ? If the product is packaged, the (non-destructive) method as routinely used in cold stores might work where the external temperature of adjacent contacting units can be shown to reflect the internal level. This is a long established SOP, eg Codex. But method may fail if there is strong, variable, air velocities in place across the product, ie insufficient equilibrium. If latter problem i suppose only direct measurement will work with (hopefully) correlation to the wall display. I have used the "indirect" method described to justify absence of product problem when defrosting coils in cold stores. (Self-calibrating TC units to work at -18degC is not easy IMEX though, the Professionals have appropriate equipment which makes the job much easier :smile: ). This method might also work in the chiller, it all depends on the actual situation/temperature variations.

You never know, yr current IR method might also be correlatable somehow. It depends on the data. :smile:

Rgds / Charles.C

PS - just noticed you mentioned use of "analog" thermometer. I suggest you be daring and buy a TC unit. If absolutely adamant, could use with a non-digital, compensated, millivoltmeter; if you can find one. :smile: