pete bottles and oxy absorbers

[storm.ridley]

hi all,
i have been repacking oats, powdered milk and rice into 2lt pete bottles, in each one i put an oxy absorber and put in dark place. i checked my stock today and its all fine and looks good. there are two bottles that dont have oxy abs in them and i noticed that the ones that do have kind of started to "vacum themselves", they are sort of pulling in around the top of the bottles the odd two out havent done this. so is this the oxy abs working and will it crack the plastic? they seem ok at the moment.
stay safe all.

[Moony]

The bottles will 'pull in' when the oxygen absorbers react with the air and remove the 21% available in the air, so you'll get a partial vacuum. Ones that don't pull in either have alot of air left in them so the amount removed doesnt get enough effect to form the vacuum or you have a leak on the seal. They are unlikely to burst or crack from this effect, the internal pressure they are designed to withstand exceeds the reverse 'vacuum' pressure they encounter when you put the absorbers in, though drying out and aging will deteriorate the plastic slowly.

Im sorry to inform you however that PETE (or PET) bottles are not airtight and no matter how well the top fits air will penetrate through the walls of the plastic and eventually you'll get oxygen back inside which will continue the process of deterioration of the foodstuffs inside. This is why pet bottled drinks generally have a shorter shelf-life than aluminium cans of the same drink. (I work in the packaging industry and we use both types). Your activities will extend the shelf-life of the products stored somewhat but I would highly recommend the use of Mylar or aluminiumised barrier bags for the long-term storage of food.

[storm.ridley]

thanks, i will get some mylar bags and oxy abs and put them in buckets with lids. do they still need to be food grade buckets if food is not directly touching the bucket? ie in a bag in a bucket.

[arnieh]

Hi I have just found a good supply of food grade buckets from my local baker (free of charge) they have icing, pie fillings etc delivered in them it seems all they do with them is throw them away. No harm in asking is there?

[Reservior]

Hi I have just found a good supply of food grade buckets from my local baker (free of charge) they have icing, pie fillings etc delivered in them it seems all they do with them is throw them away. No harm in asking is there?

Yes, great idea, just a shame there's a lack of local bakeries these days. I got all of mine from work (I work in a bakery) but these days we don't use ingredients that come in buckets, other than doughnut frying oil and those are a pig to clean!

[arnieh]

I am also going to ask if I can buy my bread flour through them, worth a try.