The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Baking with sour milk?

chiaoapple's picture

Baking with sour milk?

 I read in a baking blog that you could use sour milk in making bread – is this correct?

Note: what I mean by sour milk is milk that has gone a bit off, NOT soured milk (which was intentionally made sour by vinegar or lemon).

Does anyone bake with sour milk? If yes, is there a “cut-off” for how sour the milk can be?


Susan's picture

you can definitely use it to make biscuits!

Susan from San Diego

browndog's picture

the problem here is that modern pasteurized milk doesn't sour in the true 'old-fashioned' sense. The right souring 'bugs' are killed by the process and it just goes BAD. No, I would not be remotely inclined to do anything with it but pour it down the drain (with apologies to Susan. I'm sure milk that's just starting to turn isn't a real danger. I just let my nose be the judge. I don't know the science, but I bet somebody does.) That's why we sour milk by adding lemon juice or vinegar--we don't have access to the real thing like our grannies did. If you are lucky enough to have raw milk, that would be the ticket, you can certainly use true 'sour' milk in bread, its acidic nature will add flavor and soften the crumb. I used to get raw milk by the gallon from a local farmer, cream top and all, I always had too much milk and often had sour cream and it always ended up in the bread. If you aren't nervous about the 'bad' bug potential it's grand.

Dyske's picture

There appears to be much confusion about this topic on the Internet. The best article I found was this:

Some people on the net were claiming that it is OK to use sour milk as long as it is raw milk, but according to the article above, raw milk is quite dangerous (which is the reason why they invented the pasteurization process in the first place.).

I am no scientist, but what I gathered from reading various articles is that the reason why we get sick from sour or spoiled milk is because of the bacterias and the viruses. But, these organisms all die if you heat up the milk above a certain temperature. See the following article on Wikipedia about pasteurization:

According to this, the temperature required to kill them all is 145F. The internal temperature of bread in the oven reaches well above that, which would mean that no matter what kind of bacterias or viruses you may have in the milk (raw or pasteurized), they'll all be dead.

From this, I would conclude that you can use sour milk for baking. It does not matter what kind of bacteria was responsible for making it sour, since they'll be all dead by the time the bread comes out of the oven.

This page specifically says that it is OK to use sour milk for baking:

browndog's picture

I think that's the key. the Maine page says:

>Milk spoils quickly without refrigeration. Throw out spoiled milk. Soured milk may be used in baking.<

Soured is not spoiled. Yogurt and cheese for example, are really just soured (fermented) milk or cream. Spoiled, or 'off' milk is actually starting to decompose, not sour, since the good 'souring' bugs are killed by pasteurization as well as the disease carriers, as you noted, Dyske. I agree that drinking raw milk is certainly taking a risk, and at any rate it's impossible for most people to find.

arbormundi's picture

Excuse me but, raw milk is not dangerous and you are mistaken.  If you were to test human breast milk, you found find the same mix of pathogens that are found in raw cow's milk, but we do not pasteurize breast milk to make it safe. There have never been more fatalities associated with eating commercial milk than raw milk because one bacteria strain such as e.coli can dominate the commercial milk, unlike the raw milk, which is balanced microflora.  Also, if you look at the history of pasteurization, it came about because commercial whisky manufacturers had started CAFO farms to sell milk to city children of mothers who worked in factories in the 19th century, and the whisky industry was feeding the cows whisky slop instead of grass, and the cows were sick and untreated with anti-biotics so the milk became infected.  Once it became known that "slop milk" was causing child mortality, they couldn't compete with the farmers who wanted to sell certified raw milk (from natural sources) and lobbied congress to force everyone to pasteurize the milk. The small farmers couldn't afford pasteurization, so the cafo farms won over the milk industry.  However, pasteurization oxidizes cholesterol, which is why scientific studies since the 1940s have said that milk is linked with heart disesase.  Pasteurized milk is, but raw milk isn't.

asapersson's picture

I agree. Yes to raw milk. I love it and drink it every day. I will never go and buy a storebought pasurized, homogenized destroyed carton of milk again. Consumtion of too much of processed food is unhealty.





rudolf's picture

Browndog, that is a rather sweeping statement, Implying there are right and wrong souring 'bugs'. Perhaps you can tell me the names of the right souring 'bugs' and also the names of the wrong 'bugs'.

If you have any trouble in supplying the above, I will tell you what any biology student should know, that all milk fermentation is caused by lacto bacilli. See my earlier post

Richard L Walker's picture
Richard L Walker

I wouldn't touch bad milk with a 10 foot (meter?) pole.

Buttermilk and biscuits? Now that would be something else again.


dcbakerman's picture

A lot of irish soda breads are made with soured milk.  My friends mom is irish, lives there and just keeps one liter on the counter so she can always have "bread milk" as she calls it.

rudolf's picture

I think there is much misinformation about  sour milk, Milk, whether pasteurized or raw is soured in exactly the same way by lacto bacilli, which causes the fat to coagulate and the lactic acid environment causes the sour taste. I would be reluctant to drink raw milk because of the increased chance of ingesting harmful pathogens, I would however have no qualms in drinking fermented sour raw milk as the acid environment kills off all other bugs except wild yeast. Yes there is no reason why you cannot bake sourdough bread with naturally soured milk, either pasteurized or raw, as lacto bacilli and wild yeast are already present in the starter. I use naturally fermented pasteurized milk for baking griddle cakes and scones with baking soda as the leavening agent. This method of leavening has been used since the 1800's. Carbon dioxide is produced by the reaction of the acid in the sour milk and the alkali of the Baking soda. It is also used in the leavening of traditional irish soda bread. Baking powder could also be used without the sour milk, but why add two chemicals, which baking powder is, when you only need to add one,

senrich's picture

You guys don't know the wonders of sour milk? I grew up on a Ranch and I've had non pasturized and pasturized milk before. I don't remember sour milk being different from either one personally. Sour milk is sour milk. It's good stuff. The only dangerous bacteria that leaves toxins behind after cooking I know of would be the ones that grow slowly over time in canned goods that have been dented to allow a tiny bit of the environment in. That's botulism. Oh and I think Anthrax is a related bacteria, but I'm not sure where it comes from(and it's not interesting enough to me to Google it). You won't find that in milk though. I think it's because the other bacteria outcompete it. Yea the other bacterias get all cooked off and leave a very different flavor. A better flavor! Definitely use sour milk for pancakes! I'm not much of a yeast bread maker, but I've been making pancakes once a week for about 10 years. I get irritated when my wife or other family members throw out the sour milk. I use it from the point at which it starts to smell bad to the point just after it starts to thicken, but I throw it out after that (maybe you could us it longer, that I don't know). Sour milk is much better than soured milk (milk with vinegar)! Oh just be sure to label the milk container with a big black marker or you might find some kid(teenager or younger) trying to put it into your coffee or wasting cereal with it!

val2834's picture

Senrich, you are absolutely right!!!  Baking with sour/spoiled milk is customary.  And, if you want some delicious mac-n-cheese, cornbread and pancakes, USE SPOIL MILK; delicious!  People don't make much to do about nothing.  It is a preference.  Throw away if you are scared.  Use it if you are a cook.  It's up to you.

shodo's picture

I have been using real sour milk (not soured milk) for some years now. I've used milk that was really questionable, in recipes with baking soda, and it's always tasted good and never made anyone sick. This was pasteurized milk.


By the way, if you can get real raw milk from a carefully tended dairy, it's much healthier than pasteurized, homogenized milk. Louis Pasteur invented pasteurization as a temporary measure until they could get the dairies cleaned up. But they never cleaned them up. Pasteurization doesn't protect from Crohn's disease, and homogenization changes the calcium in milk from useful for your body to harmful (big molecules, can't be absorbed). (Boiling cures both problems.) A healthy cow is the best solution. Factory farms are the problem.

brian camp's picture
brian camp

I have to agree with Shodo on Raw Milk.

I have been drinking raw (unpasterized and un-homogenized) milk for years.  There is absolutely no comparison to store milk which basically rots rather than sours. 

The milk industry has scared the public from raw milk.  The dairy is the key. I buy from a small family dairy (google cornerstone raw milk dairy estacada, oregon), you can see the process start to finish and can attest to the cleanliness of cows etc. Grass fed cows produce milk with more color and the flavor just cannot compare.  My spouse drinks non-fat, so I let the cream rise and skim to make butter or heavy whipped cream.  cultured butter is another soured product as is yoghurt.  I could go on and on....  If you care about the best ingredients when baking/cooking then try this some time.  and no I am not connected or related to the owners.

copyu's picture

Pasteur was more interested in the matter of preventing beer and wine from going off

The dairies got into the 'pasteurization' idea quite a bit later...Just FYI...



houlyn's picture

Milk is a nice place for bacteria and other microorganisms to live.  Rudolf, I'm a biochemist but not an expert microbiologist in the dairy industry, and I think Lactobacillus is not the only microorganism responsible for milk fermentation whether it be raw or pasteurised.  Lots of different microorganisms make different fermented milk products with different flavours. 

Just as there are lots of edible microorganisms in dairy products, there are some that could cause disease (salmonella, E. coli, listeria).  Rudolf, I think Browndog is talking about these disease causing microorganisms when he/she refers to "bad bugs".  Just to clarify, pasteurisation does not sterilise (kill all microorganisms) milk, it just kills a lot of them.

As Dyske said, it's probably OK to use either raw or pasteurised milk for baking if they've started to sour (grow microorganisms) because the heat will kill them.

I'm not pro-raw or pro-pasteurised, but personally I would choose to drink sour raw milk over sour pasteurised milk.  I haven't studied the literature comprehensively though.  Some people theorise that if you get raw milk from a good source, the edible microorganisms may create an acidic environment unsuitable for the disease causing ones, or the edible ones may grow faster and take all the nutrients.

Other people say the data is on the side of pasteurised milk and that you shouldn't drink raw milk whether it is fresh or sour.

All in all, it just shows that whatever you eat, or drink, it's best to know where it comes from and who is monitoring it.

houlyn's picture

The last title spelled "Lots" wrong.

Also, I wanted to add that even after pasteurisation, edible or disease-causing microorganisms could multiply.  They could be the ones not killed by pasteurisation or they could be introduced from outside the container.

nicodvb's picture


a friend of mine made a sourdough bread using ~200gr of soured milk (which was pasteurized) and she told me that both the bread and the soured milk had a buttery flavour. I searched a lot and found out that the butter flavor is given by diacetyl,  a substance that is released by certain bacteria in particular conditions (one of which is the presence of some form of citrate). My question is: did you have the same buttery flavor, too? Was it a lucky case that is not repeatable?

I'd like to have the same flavor in my bread, but how to I create the right conditions? I was thinking to let sour some raw milk that I can  get easily.

Julien's picture

A few people said ther were using baking soda with sour milk.

Rudolf, you are saying : Carbon dioxide is produced by the reaction of the acid in the sour milk and the alkali of the Baking soda.

So, if I dont want to use baking soda as the alkalin agent but something more natural. What would you recommand me ?Sourdough ?


Fishcuit's picture

I have started making kefir. I would assume baking it in goods would kill all the good stuff in it but one can only eat so much tzatziki and such.  I am looking at using it in bread recipes, muffins, scones, cakes etc.  Two day kefir is pretty much the same thickness as sour store bought milk.

Heidela123's picture

Please do not feed raw dairy products to children under two, pregnant Women, immune compromised or frail elders...( I am a nurse, in my experience, food borne illness is way too real ) that said I raise chickens and ducks, eat raw eggs in sauces, drink raw goats milk every day, raw eat fresh cheeses, yogurt and kefir with reckless bandon, so do my kids and husband, but my frail father and little grandkids get cooked, coddled or pasteurized
Sour milk is wonderful for baking as an acidifing agent it helps lift and flavor. I freeze it before it goes beyond usable so I have it on hand for biscuits, scones, sopapillas ect
Kefir gives a real lift to baked goods! Pancakes are amazing I added a cup of Kefir to my sourdough spelt loaf on Saturday, it made it so light fluffy and flavorful!
I forget to bake with the kefir because we use it up so fast.
Yogurt is good as well if it is just milk and has no fillers

Whole fat fermented dairy is ideal for adding to baked goods

If you want really nice sour milk
Toss a couple of grapes into a quart of whole milk, let it sit loosely covered overnight

If you have never tried kefir, I can not speak highly enough of it.