I seriously can not tell you how many close calls I’ve had.
In the baby days, parents are HYPER diligent about perfectly tracking, mixing (if using formula), and sterilizing bottles used for milk.
Once the toddler years come and milk is sort of an optional, ‘whenever the kid feels like it’ endeavor, you tend to end up with a lot of half-finished sippy cups of milk lying around the house.
(And in between couch cushions and rolling around on the floor of your car. Just admit it, we’ve all been there.)
So it’s a common problem and a common question: What happens if your child or toddler drinks some old, spoiled milk?
If your baby or toddler drinks old, spoiled milk, the most likely scenario is that nothing too serious happens.
It’s possible to get food poisoning from spoiled milk, which would result in an upset stomach, vomiting, and/or diarrhea, but it’s unlikely you’d need to seek medical treatment for anything more serious.
But let’s dive a little deeper.
What happens to milk as it spoils
There are multiple ways milk can spoil, turn, or “go bad.”
Old milk left in the refrigerator
You’re probably familiar with the idea that bad, old, or sour milk can be used to make lots of different dairy products, like yogurt and cheese.
This is a pretty heavily controlled process, but you can see parts of it on display in your fridge if you let some milk turn.
When your standard, store-bought pasteurized milk starts to go bad, a bacteria present in the milk called Streptococci starts to eat away at the lactose, raising the pH of the milk to highly acidic levels. Another bacteria called Lactobacilli soon takes over doing the same thing. At this point, the milk is incredibly sour to the smell and taste.
Lactobacilli is actually a pretty integral part of the cheesemaking process, so you know it’s not the worst thing in the world.
To this point, the milk may be pretty gross, but is probably not harmful.
Left any longer than this, and other kinds of yeast, mold, and a sometimes harmful bacteria called Bacillus start to get involved and transform the milk into something you probably want absolutely no part of.
It’s hard to say exactly when that will happen, but you’ll probably know with a quick eyeball or sniff test. (If your milk has visible mold on it, EJECT! EJECT!)
In general, don’t keep milk much longer than about 5 days after the Sell By date.
(Pro tip: Store your milk near the bottom, or coldest part, of your fridge to make it last longer and stay fresher.)
Milk left out in room temperature
The cool temperature of the refrigerator helps keep a lot of different bacterias in check. Out in the open for long periods of time, the results of spoilage are a little more unpredictable.
In short, anything goes outside of the fridge.
The general rule of thumb is that the safety timeline of milk shortens as the temperature rises.
Milk left on the kitchen counter with the AC blasting will be OK for longer than a sippy cup trapped wedged in the carseat on a 90 degree summer day.
A lot of the same processes will start to happen as mentioned above; the milk’s natural bacteria will start to feast on its various components and sour the milk. Out in the open, other bacteria can get involved, though today’s modern pasteurized milk has very little bacteria present in it.
That is to say, it’s likely that milk left out for a while isn’t so much dangerous as it is disgusting.
In general, the FDA recommends not leaving milk (or any refrigerated food) out for more than 2 hours.
UHT (ultra high temperature) milk
Sometimes, at the grocery store, you’ll see milk or milk products packaged in cardboard sitting on room temperature shelving.
This kind of milk is really common in many European countries.
Does that mean UHT milk is immune from spoilage?
It’s ultra pasteurized, i.e., it’s been extremely heated to kill almost all bacteria in it. That’s why it can sit out the way it does.
Once you open it, though, and contaminate it via open air, a lot of the same rules apply:
Store it in the fridge for a week, tops, and don’t leave it sitting out for more than 2 hours.
The Verdict – What happens & how long after drinking spoiled milk will a toddler get sick?
There are a LOT of factors that go into how worried you should be about your toddler drinking spoiled milk.
What kind of milk is it? Has it been in the fridge? Has it been in your hot car for a month?
(It sounds horrifying, but I wouldn’t put it past a toddler to take a swig of near-solid, moldy, curdled milk.)
In most cases, probably the worst thing that will happen to your baby or toddler from drinking old milk is a case of food poisoning.
The more likely thing is that nothing at all will happen.
In all likelihood, the milk won’t be that dangerous, and they won’t drink enough of it to get seriously ill. (I don’t think even a toddler could stomach multiple glugs of milk that had been sitting out for days or weeks.)
(Important note: I’m not a doctor and don’t claim to be. You know your own child… if you think something is wrong, or your parent-alarm is going off, by all means take them to a doctor or medical professional. I’ve just done the best job I can here compiling available resources and information.)
How to spot food poisoning from bad milk
If your kid has a little bit of questionable milk, there’s probably no need to rush them to the hospital.
Monitor them carefully for signs of food poisoning, which include:
- Stomach cramps
- Excessive gas
- Achey muscles
The best thing for most cases of food poisoning is lots of rest and fluids. It will pass on its own as the body flushes the bad bacteria away.
If the diarrhea lasts for more than 2 days, or if the fever keeps climbing, you may want to call a doctor. In fact, your best bet would be to read the whole WebMD page on food poisoning just to be safe.
How to spot botulism
It’s not likely, but it’s possible (especially with raw or unpasteurized milk) that if it goes really, really bad it could contain E. coli or other more harmful bacteria.
These can cause botulism, or an extreme form of food poisoning.
Along with the symptoms above, absolutely call a doctor if you notice any of the following:
- Slurred speech or blurred vision
- Muscle weakness
- Hard time swallowing
- Dry mouth
- Muscle paralysis from the head down through the body
Again, this is pretty unlikely in the case of a toddler taking a sip of some spoiled milk, but you’re here to be prepared for any scenario, so there it is!
The best defense & remedy for drinking spoiled milk
The best way to avoid any of this uncertainty — and possibly, a nasty case of food poisoning — is to scoop up all of those milk sippy cups as soon as possible and dump them down the sink.
Believe me, I am as guilty as anyone!
My daughter likes to carry her milk around the house, take it in the car, throw it on occasion. Who knows where these things are likely to end up.
But the safest thing and the best way to avoid this entire scenario is to be super diligent about disposing of milk as soon as your toddler is done drinking it.
It’s a throwback to the newborn days, but it’s probably the best way to ensure your kid doesn’t end up drinking sour, curdled milk.
According to Poison Control, the best remedy for a toddler that drank bad milk is small but frequent sips of water to prevent dehydration in the event of vomiting.
All of that being said, probably the worst thing about old milk is that it’s disgusting.
It looks disgusting. It smells disgusting. It probably tastes disgusting.
And for that reason, if milk is really in the danger zone, and is super old, and MOLDY, and ripe with harmful bacteria, I truly can’t imagine a toddler drinking more than an accidental sip of it.
Again, I’m not a doctor, but from everything I’ve found, the probable worst thing that’s likely to happen is a brief, self-curing case of food poisoning.
But even more likely than that is you and your kid both learn a valuable lesson about disposing of old milk.
Even if they throw up or have a few runny poos, it doesn’t mean they’re “ill” from drinking the milk. Food poisoning is common and passes on its own with proper rest and hydration.
It also doesn’t mean you’re a bad parent!
It’s almost impossible to keep track of everything you need to as a parent. A stray sippy cup of milk that sat out too long is par for the course.
In summation: Just breathe. Everything is probably fine. If your kid got a hold of some bad milk, just watch them carefully for signs that anything is amiss.
I hope this has helped ease your mind! If you found it helpful, scroll down to find out how you can get even more of my best research, hacks, and stress-saving tips.
And good luck with your next parenting puzzle.