If you’ve finished re-watching Downton Abbey (for the second, third, or fourth time), you may be itching for a nice, strong cup of tea.
Without a doubt, a cup of tea is a great way to pep up for the day or wind down for a restful night’s sleep, no matter where you hail from. However, a classic add-in, milk, should be used with caution.
Milk and cream will curdle when added to a cup of tea if there is an acidic component to your tea (IE, citrus oils), or if the tea is at too high a temperature. If you’re drinking a citrus-based tea, such as lemon, or any other acidic tea like hibiscus, you will want to avoid adding dairy. Other teas, such as peppermint, are less acidic and are perfectly compatible with dairy – just make sure it isn’t too hot!
It is also important to know exactly how curdling happens, when dairy is no longer safe to drink, and what happens if you drink curdled milk.
We’ll give more details on these points below.
Is It Ok to Drink Curdled Milk or Cream?
If you’ve already added your dairy product to your cup, taken a sip, and are now noticing the unpleasant lumps associated with curdling, you’ll need to do a little investigating.
First, it is important to note that curdling does happen naturally over time, but can also be caused unintentionally (or intentionally, such as to produce cheese).
Dairy naturally curdles when the good bacteria produces lactic acid, lowering the pH to a more acidic state and giving the milk or cream a sour taste and lumpy texture.
This process is quite easily observable; if you can see lumps, or a sniff of the dairy product has an unpleasant sour odor, you can assume it has spoiled and is not safe to drink.
Be sure to check your milk or cream if you notice lumps in your tea after adding it, to see if it may have already started to sour on its own.
A small sip or two of curdled milk will not cause any harm, though you may experience some GI discomfort as you would with mild food poisoning.
Dairy will curdle unintentionally when, as mentioned earlier, it comes in contact with an acid or high heat.
This doesn’t necessarily mean that the dairy is spoiled or unsafe – however, for dairy that is close to expiring, heat and acid will speed up the curdling process.
If your dairy didn’t show signs of spoiling before adding to your tea, but then curdled when added to a non-acidic, not-too-hot-tea, that may mean it was close to expiring.
Can You Prevent Milk From Curdling?
Milk will naturally curdle (spoil) over time as the bacteria work to produce lactic acid. Unfortunately, there is nothing that can be done to prevent this process.
Cool temperatures, such as within a refrigerator, help to delay the process. Conversely, leaving a carton of milk on the counter overnight may speed up the process (and certainly increases risk for other bacteria to form).
However, if you are worried about milk curdling when adding it to tea or coffee, or while you are using it to cook, there are a few tips and tricks to help prevent the curdling process from happening unintentionally.
- Add starch
If you’re cooking with milk or cream, adding a bit of starch to your pan first (IE, flour or cornstarch) and then adding your dairy will stabilize the milk emulsion and prevent curdling.
This can also be a great thickening agent when making recipes like sauces or soups.
- Make sure to keep heat low
High heat and boiling will trigger the curdling process, so be sure to keep the heat low if you are heating cream or milk to make a sauce.
- Use cream instead of milk
Cream is a great substitute for milk when cooking, as it has a higher fat content than milk does.
Higher fat content acts as a stabilizer and helps prevent curdling when cooked at a higher heat.
How Do You Know if Milk or Cream Has Gone Bad?
There are a few easy ways to check whether your milk or cream have gone bad before even using it:
- Check the expiration date
If kept properly refrigerated, unopened milk will generally last 7 days past the expiration date, while unopened milk generally lasts 3 days past the expiration date.
Cream will also last within a week. The dates printed on the package are meant to be an indicator of how long the quality will last but will give you a good idea of when the product may begin to spoil.
- Give it a sniff
When milk and cream have gone bad, the acidity of the emulsion will give off a distinctly sour smell, while fresh milk and cream usually do not have much smell at all.
If you notice any sort of order when sniffing, it is safe to assume your dairy has gone bad.
- Examine the color
Milk and cream normally are white in appearance.
When it has started to curdle and the proteins have begun to clump together, the dairy product will appear yellow when poured into a clear glass. If you notice a yellow tint, toss it.
At What Temperature Will Milk Curdle?
If you are cooking with milk to make a variety of sauces, soups, and the like, chances are it will need to be exposed to heat.
While this can create a creamy and delicious result, the heat does pose a challenge that will need to be carefully navigated.
Milk will ultimately curdle when exposed to heat at a temperature of 180 degrees Farenheit, or 82 degrees Celsius.
Boiling guarantees you will reach this temperature and curdle your milk, but at times even simmering, or trying to heat too quickly, will also.
If you have a kitchen thermometer at hand, it offers the most precise method of ensuring your heat remains below the curdling threshold.
If you don’t have a thermometer handy, the best way to ensure your milk isn’t being heated at too high a level, or too quickly, is to keep the heat of your stovetop to medium-low.
If it starts to simmer too vigorously, remove your pan from the stovetop to allow it to cool, and lower the heat.
Why Do Milk and Cream Curdle in the Refrigerator?
Eventually, all dairy products (including milk and cream) will curdle, even when stored in a refrigerator at 40 degrees Fahrenheit or below.
Milk and cream are both comprised of a mixture that we call an emulsion. Emulsions are made up of three components: fats, proteins, and water.
When the pH balance of the emulsion is lowered to a more acidic level, the proteins bind together and separate from the other components, producing the clumps that we recognize as curdling.
Cold temperatures, such as within a refrigerator, delay this natural process from happening by keeping the pH level stable for longer, though eventually, the dairy will curdle as the good bacteria produce lactic acid that lowers the pH of the emulsion.
Overall, dairy products such as milk and cream can be expected to curdle naturally over time, but factors such as heat and acidity can cause the process to happen almost instantly when added to a cup of tea.
Make sure you are carefully monitoring the expiration date of your dairy product to ensure the best quality and most enjoyable sipping experience.