# What makes milk white? **URL:** \ **Category:** Factual Questions\ **Created:** [February 15, 2004, 3:51pm UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357 "2004-02-15T15:51:25Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![biddee](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@biddee](https://boards.straightdope.com/u/biddee)\ **Post date:** [February 15, 2004, 3:51pm UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/1 "2004-02-15T15:51:25Z")
I have a 3 week old daughter and was pumping breastmilk last night and started to wonder why most mammal milk is white? Is any mammal milk any other colour than white? Thanks in advance. ---
**Author:** ![gluteus\_maximus](https://avatars.discourse-cdn.com/v4/letter/g/f17d59/32.png) [@gluteus\_maximus](https://boards.straightdope.com/u/gluteus_maximus)\ **Post date:** [February 15, 2004, 4:02pm UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/2 "2004-02-15T16:02:31Z")
You obviously haven’t been eating enough chocolate. 😉 [Calcium](http://www.coolquiz.com/trivia/explain/docs/milk.asp) is the reason for your milk’s milkiness. ---
**Author:** ![gluteus\_maximus](https://avatars.discourse-cdn.com/v4/letter/g/f17d59/32.png) [@gluteus\_maximus](https://boards.straightdope.com/u/gluteus_maximus)\ **Post date:** [February 15, 2004, 4:09pm UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/3 "2004-02-15T16:09:09Z")
Oh, wait… It seems the above cite contains fallacies… myths… mistakes… falsehoods, even… well, only partly. Milk is white [because](http://www.du.edu/~jcalvert/phys/milk.htm)… ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 15, 2004, 5:14pm UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/4 "2004-02-15T17:14:11Z")
The answer I was going to give coincides pretty well with the second link that **gluteus maximus** posted, so I think he has a winner. ---
**Author:** ![muttrox](https://avatars.discourse-cdn.com/v4/letter/m/a8b319/32.png) [@muttrox](https://boards.straightdope.com/u/muttrox)\ **Post date:** [February 15, 2004, 5:29pm UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/5 "2004-02-15T17:29:53Z")
FWIW, Mammals are the only animals that give milk – one of the defining characteristics. So I think “mammal milk” is redunant. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 15, 2004, 6:24pm UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/6 "2004-02-15T18:24:25Z")
True, but the use of “milk” for any white fluid is widespread and as old as the hills. Soy milk, rice milk, nut milk, coconut milk, milk of magnesia. Going to [dictionary.com](http://dictionary.com) I see a bunch of other uses even I was not familiar with: > [@](#): > > 1. (Bot.) A kind of juice or sap, usually white in color, found in certain plants; latex. See Latex. > > 2. (Zo["o]l.) The ripe, undischarged spat of an oyster. > > Milk of lime (Chem.), a watery emulsion of calcium hydrate, produced by macerating quicklime in water. Same with butter, used to denote any thick spreadable edible, as in peanut butter, apple butter, etc. Distinguishing mammal milk from these is not necessarily a bad idea even if the term itself is redundant. ---
**Author:** ![bbeaty](https://avatars.discourse-cdn.com/v4/letter/b/c0e974/32.png) [@bbeaty](https://boards.straightdope.com/u/bbeaty)\ **Post date:** [February 16, 2004, 12:59am UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/7 "2004-02-16T00:59:15Z")
Mix some baby oil with some water in a blender. Turns white! (Vegetable oil, cod liver oil, …baby oil.) ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [February 16, 2004, 1:13am UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/8 "2004-02-16T01:13:31Z")
> [@muttrox](#): > > FWIW, Mammals are the only animals that give milk – one of the defining characteristics. So I think “mammal milk” is redunant. Not quite; some birds produce ‘crop milk’ to feed their chicks, admittedly by a completely different process to mammalian milk. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 16, 2004, 2:18am UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/9 "2004-02-16T02:18:09Z")
First hit on Google for [crop milk](http://www.cmnh.org/dinoarch/1995Jun/msg00837.html). > [@](#): > > They do produce a milky susbstance called > crop milk. It is regurgated from the crop which is part of the digestive > system. It providesurishment for the nestling. It is very different in origin > from the milk of mammals and in composition. At best, it is a case of > convergence. The tissue is different, the product is chemically different. Even as a nitpick, I think this is stretching it. 😉 ---
**Author:** ![muttrox](https://avatars.discourse-cdn.com/v4/letter/m/a8b319/32.png) [@muttrox](https://boards.straightdope.com/u/muttrox)\ **Post date:** [February 16, 2004, 2:01pm UTC](https://boards.straightdope.com/t/what-makes-milk-white/229357/10 "2004-02-16T14:01:12Z")
I retract my previous response. I had just read David Attenborough’s excellent “Life of Mammals” where it (along with body hair) were cited… I couldn’t contain myself! 🙂