8 replies to this topic

[trubertq]

Hello peeps,
My Company are using tempering unit to defrost frozen shellfish.. Sous Vide Crab, Whelks etc... the problem is that it is taking 48 hrs for the stuff to defrost, and as orders come in Thursday for Dispatch Friday this is not ging to work for us. I am wondering is there any way to speed up the process without losing control of the process.

As far as I know they have the unit at 4 degrees during the process.

I know that the temptation to use ambient temperature is great and then .......I don't want to think about what happens after that......

[Charles.C]

Dear trubertq,

There are many variables involved in addition to yr mentioned temperature.

Example , 1ton batches of approx.7kg units of semi-block (thin glaze) fish divided between numerous stainless tanks , occasional manual agitation, temperature approx 5degC (maybe +/- few degC), average time 15-20 hours, water-to-fish weight ratio unsure but probably critical.

Rgds / Charles.C

[GMO]

You can purchase accelerated defrosting units which do raise the temperature. From experience with cooked chicken, to make a process safe you have to consider the surface and core temperature which for a chicken breast can be considerably different. You will probably need a carefully controlled process which is carefully monitored. I would suggest that as soon as the surface reaches zero you then return to chill for the remainder of the defrost.

I take it as these are sous vide, they're all in pouches and so of considerable size and density? It all makes it harder. I don't know how you perform the defrost but by putting the bags onto open racks it will help air flow.

If you want to trial this, I'd approach it by getting in a portable unit capable of performing an accelerated defrost program (you can hire these in trailers in the same way you can hire additional chiller capacity). I'd then use a datalogger measuring surface and although it can't be accurate until it defrosts, I'd drill in and measure core as well. Do this top, middle, bottom in several places in the unit and monitor manually as well. Then do micro etc. Using this kind of data, hopefully you can design a process and a programme which can then be run with monitoring. It's not the risk free option but I would say your current process does not meet your requirements so you do need to try something new.

[GMO]

Oh and obviously during your process design (ie validation) stage, do some micro as well.

[Jomy Abraham]

What about running water at 21 Deg C. Will it work?

Regards
Jomy Abraham

Hello peeps,
My Company are using tempering unit to defrost frozen shellfish.. Sous Vide Crab, Whelks etc... the problem is that it is taking 48 hrs for the stuff to defrost, and as orders come in Thursday for Dispatch Friday this is not ging to work for us. I am wondering is there any way to speed up the process without losing control of the process.

As far as I know they have the unit at 4 degrees during the process.

I know that the temptation to use ambient temperature is great and then .......I don't want to think about what happens after that......

[Charles.C]

Dear All,

Actually i had assumed the enquiry referred to original raw material prior to sous-vide / whatever processing. ?

Just shows you the value of information.

Back to trubertq.

Rgds / Charles.C

[GMO]

Well that's true. Perhaps you can clarify?

If it's shellfish IQF with an ice glaze from experience at defrosting prawns like this in a domestic kitchen, you can still have ice on the outside when the inside is almost defrosted. Very strange. In the past though where we've had to defrost like this, where possible for prawns we've kept in the supplier bags and generally found that at 4 degrees after 24 hours they're defrosted if they're put onto racks with plenty of air circulation.

It would give a bit more of an idea as to the risks etc if you give us some guidance on what the process is?

[trubertq]

The product is sous vide crab mainly, in pouches..usually packed on trays sometimes in a master carton...

The whelks are in shell ... pasteurised in sealed trays usually 500g to 1kg packs...

I think it's case of trial and error until we find the most efficient way of doing it... and I agree that data loggers are the best way of monitoring ...with subsequent micorbiologocal testing... alas this is destructive and the prodct is very valuable... ho hum...I won't be popular!

[GMO]

No you won't be popular when you suggest the trial but when you point out that it will potentially save 24 hours on the defrost time there might be some supporters. Why don't you have a look through the data on holds and fines and lost sales due to non delivery which have resulted from this 48 hour process then you may find that the costs are recouped in no time.

Operations people understand money and efficiency...