Bitter taste in fresh milk

Dear all,

right now, we have some complain, that our product (fresh milk in tetra packaging) hv bitter taste, our product use pasteurization, and only hv ED 14 days

our microbe result is okay,

but when we taste teh product we found bitter taste,

does anyone hv experience why this happen to our product?

Thank you

Hi

Have you considered improper rinsing after cleaning?

Are you able to test for cleaning chemicals? QAC QAT etc.....

Do you use any additives? Any thing added that may have been added in too high an amount etc?

Dear ben, we already check pH and microbe for the last rinsing, we use hylite, and we record all (temperarture, concentration, flowrate and time) Thank you

Dear all,

 

right now, we have some complain, that our product (fresh milk in tetra packaging) hv bitter taste, our product use pasteurization, and only hv ED 14 days

our microbe result is okay,

but when we taste teh product we found bitter taste,

does anyone hv experience why this happen to our product?

 

 

Thank you

Could be any number of issues generally catagorised as

Absorbed

Bacterial

Chemical

Not sure if you have seen these websites? PSU    FAO   -they give a good overview of possible causes of 'off flavours' in milk

Mike

I still refer to the blue book! 

Caz x

what is the micro quality of the raw milk

possibly high psychotrophic bacteria

what about your suppliers it may be chlorophenol taint which will be traced to you suppliers cleaning processes.

Is the packaging OK?

I'm not a milk expert, but I'm wondering if the diet of the cows could be important for the "A" in absorbed.  My mother used to say that she tasted garlic in the springtime in the milk due to the wild garlic that is first to grow in pastures.  Could this be part of the issue?

http://extension.psu...flavor-problems

If you are not having any 'blown' or exploding boxes, it's possible that the problem is not microbial, thus this leads you to chemical or farm taint.

The question of the cow's diet already raised should be explored, as well as whether they have been given any new medications. Also, has the farm changed the chemical or method for cleaning the udders before milking?

Naturally I also agree with checking if any chemicals used in the dairy plant could have gotten into the milk.

If you find nothing from checking chemical or farm taint, then given that your milk is in tetra pack which is aseptic and oxygen-free, you could also check the anaerobic microbial count as it is unlikely that viable aerobic microbes are present hence your satisfactory micro-B result.

If you think that all operational procedures are Ok in factory, and all quality tests are also Ok, perhaps the problem is in your milk supplier.

In my opinion you should clarified with the supplier if there was any change in animal feed or any other problem/change occurs.

If you can not identify the problem, you should order a small amount of raw from a new supplier and see if the taste remains equal. Yes, could be expensive, but at this moment the complains are a bad sign and cost money as well.

Rgds.

Dear all,

Thank for sharing your experienced,

we already check packaging, the result is also good, mocrobe final product is also good,

but we found some information, our product is suggested storage in 4 deg celcius, we check in outlet we found that our product keep on 8 or 9 deg celcius

btw our complain is come from product that keep in 8 or 9 deg celcius

then we check TPC on that product, and we found more than 1000 cfu/ml. (Our competitor product also keep in this temp but their product hv good microbe ) i read from ingredients same like us, only fresh milk

but usually microbe hv sour taste, but this product is smell good like fresh milk, but hv taste bitter

does anyone have experienced like this?

Thank You

Dear all,

 

right now, we have some complain, that our product (fresh milk in tetra packaging) hv bitter taste, our product use pasteurization, and only hv ED 14 days

our microbe result is okay,

but when we taste teh product we found bitter taste,

does anyone hv experience why this happen to our product?

 

 

Thank you

Hi there,

Sounds like Pseudomonas to me but it would be useful to get more information.

When you get a TPC result of >1,000/ml you should be looking at further dilutions to get an accurate count.

Are you testing at start and end of life? If the bitter taste isn't there at the start then it is likely to be micro activity or residual micro enzymes*

Are you checking for psychrotrophs - plate count 21 C?

* Do you rework milk into these products?

Regards,

Tony

Dear all,

 

Thank for sharing your experienced,

we already check packaging, the result is also good, mocrobe final product is also good,

but we found some information, our product is suggested storage in 4 deg celcius, we check in outlet we found that our product keep on 8 or 9 deg celcius

btw our complain is come from product that keep in 8 or 9 deg celcius

then we check TPC on that product, and we found more than 1000 cfu/ml. (Our competitor product also keep in this temp but their product hv good microbe ) i read from ingredients same like us, only fresh milk

but usually microbe hv sour taste, but this product is smell good like fresh milk, but hv taste bitter

does anyone have experienced like this?

 

Thank You

Hi. Were you able to figure out the problem? I'm too looking for a solution. So far my colleagues at milk plant have dismantled TBA, reception tank and CIP connections, hot air connections and its buffer tank and checked / replaced some warn gaskets. Also some pipe connections were found to be building up milk residues and were washed / removed. Still they find one (that's 10 tons) out of two batches developing bitter taste. The manufacturer advised additional tests for spore forming bacteria, particularly Bacillus species. They've checked all dead points and nothing seems culprit at the production line though.

Hi Sean,

Is this fresh or UHT milk and are you finding high micro counts?

Also is the milk reconstituted from milk powder?

Kind regards,

Tony

Hi Sean,

 

Is this fresh or UHT milk and are you finding high micro counts?

 

Also is the milk reconstituted from milk powder?

 

Kind regards,

 

Tony

Hi Tony. This is UHT milk. TPC is as high as 100,000 cfu/ml. It is produced from fresh milk.

Regards, Sean.

Hi Sean,

If you have a major sterility problem then normally all batches would be bad. There must be a reason why you have a good batch then a bad batch.

Have you looked to see if there is any difference in plate count and spore count for the fresh milk used in a good batch and compared it with a bad batch?

Is the good batch produced first in a day's production?

In a bad batch is the contamination spread throughout the run or does it start at a particular time?

Kind regards,

Tony

When they traced back to supplied fresh milk, they found little difference in TPCs for good and bad batches produced. Unfortunately the plant launched spore counts after the complaints began knocking at the door so now they don't have any past data on spores. The dairy runs in a manner like "first-come, first-served" so it is really hard to figure out production risks there. I'll try to get more information when I visit the plant and also need to review process records for close insight.