Newbie to MRE's

[Richard w.]

The real purpose of the beverage powders is to mask the taste of water that's been treated with iodine tablets or been sitting in a water can or buffalo for too long.

I used to pour them straight into my canteens. Makes even warm water a little more palatable.

[kman]

I read in one of the Natick/DSCP updates that the reason they started using bigger beverage base bags was to encourage soldiers to use the bag to mix and drink the beverages. They were concerned that if you put the beverage base into a canteen, it'd be too difficult to properly clean the canteen out and so maybe bacteria would start growing.

Did you ever have that issue?

[Richard w.]

Yeah, I recall reading something like that, too, but I never heard it articulated as an actual policy. It kind of puzzles me, because I had always thought that sugar is an excellent inhibitor of bacterial growth. Doesn't everybody have a half-eaten jar of jam in their fridge that's at least a year old?

I've no doubt that our hip canteens bred all kinds of crud. Just the act of drinking from them puts bacteria in them. After weeks or months of continual use without proper cleaning, they get a sour-milk smell and taste to them. When we came out of the field, I used a mild bleach solution to rinse mine out. Good as new.

But no, I don't believe mine grew anything harmful in them. At least, nothing that I noticed.

[Demoncase]

"that sugar is an excellent inhibitor of bacterial growth"

100% Ass Backwards, I'm afraid....We use sugared water to grow bacterial broths in the laboratory. Sugar is excellent encourager of bacterial growth.

What makes Jams and preserves keep for so long is the high acidity which prevents baterial growth, as well as the aseptic conditions in which they were made: You have to boil AND sterilize jam jars religously before making them, then seal the tops with a wax disc AND a screwcap....Plus jams are boiled completely before jarring, which kills any bateria/ funghal spores in the jam itself.

If jams were resistant to bacteria then you wouldn't have to refridgerate them....

Most bacteria and funghi that spoil food need the following to survive:
1. Moisture or rather free/ available liquid water(Hence Freeze dried foods last longest)
2. Sugar or Starch- for food.
3. The correct temperature range (Below 40oC and above 0oC- hence freezing for preservation and boiling for sterilisation)
4. The correct pH range (Fairly close to Neutral pH7 for most, though there are some that prefer more acid or more alkali)

below freezing- bacteria are dormant
Above 40oC and their proteins begin to scramble and they die
Remove the water and bacteria cannot carry out the chemical reactions they need to metabolise sugars and/or die from catastrophic osmotic shift.
Remove the sugar- no food to grow and multiply- some species die, others encyst to dormancy
Change the pH beyond the tolerance range of the species and again, at the cell membrane, chemical reactions and osmosis gradient are totally buggered up.

There are some resisitant little bugs that need 75oC+ to sterilise (Pyrlobacter in Yoghurt springs to mind) and some, non-food spoiling funghi make their own water to grow (Dry Rot or Lachrymans, which means "weeping" in Latin, makes a tiny drop of water at it's growth face to grow into)....but must all food spoiling bacteria are killled by over 75oC and made dormant by sub Zero conditions.

PS- this is from memory, not Google

[kman]

Good bit of information to know, Demoncase. Right before I read your message, I popped open my 6-month old jar of grape jelly for some breakfast. I marveled at how there wasn't anything growing in there. Now I know it was because of the acidity!

[Demoncase]

There are bacteria in it, and growing too!

The low temperature and low pH are just making the colonies grow much more slowly....And also limiting the growth to harmless species.

Have you never wondered why your stomach is full of hydrochloric acid strong enough to eat through a car hood?...One reason is digestion but another is to destroy ingested harmful bactieria.

Start messing with the pH of you stomach freqeuntly (chewing up Tums a lot for eg) and you run an increased risk of contracting some form of digestive disorder...aka The Squits

[Richard w.]

I stand corrected about sugar and bacteria, etc.

Any of you guys that put beverage powders in your canteens have been warned!

[Demoncase]

That's the reason why the Milkshake packets reccomend drinking within 1 hour of consumption....not because it will taste nasty, but an unrefridgerated dairy product is just about the perfect environment to ensure rapid growth of bacteria..