# Environmentally friendly disposal of spoilt milk **URL:** \ **Category:** Factual Questions\ **Created:** [January 18, 2018, 10:24pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925 "2018-01-18T22:24:40Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [January 18, 2018, 10:24pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/1 "2018-01-18T22:24:40Z")
So, it’s happened again, we lost another gallon of milk to spoilage. Blame a large wholesale chain that sells milk in two-gallon boxes. I poured the milk down the drain before crushing the plastic jug and tossing it into the recycling bin. But that got me thinking: _what is the environmentally responsible way to dispose of spoilt milk?_ Besides pouring down the drain, which goes into the city’s sanitary sewer system, I could sprinkle it over the lawn. It certainly needs water. Or pour it into the street gutter, which goes into the LA river. Which of these is my best option? Other people have compost piles. Or pigs to slop. Are those reasonable for anyone who has those options? ---
**Author:** ![Weisshund](https://avatars.discourse-cdn.com/v4/letter/w/ba8739/32.png) [@Weisshund](https://boards.straightdope.com/u/Weisshund)\ **Post date:** [January 18, 2018, 10:31pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/2 "2018-01-18T22:31:06Z")
Probably go put it out on the lawn and then dilute it a little with the sprinkler? Down the drain i guess you might say is a waste, some of the milk content nature could recycle back into the plants etc. ---
**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:** [January 18, 2018, 10:47pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/3 "2018-01-18T22:47:08Z")
You could pour it out in a bowl and leave it to curdle completely, and dry out, then become infested with maggots - those maggots would turn into flies which are food for spiders, birds and small mammals. The leftover residue could be added to the soil around plants to nourish them. ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [January 18, 2018, 11:01pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/4 "2018-01-18T23:01:32Z")
The pests you’ll attract to your house/neighborhood outweigh whatever inconsequential environmental benefit there might be. Just pour it down the drain. ---
**Author:** ![araminty](https://avatars.discourse-cdn.com/v4/letter/a/b5e925/32.png) [@araminty](https://boards.straightdope.com/u/araminty)\ **Post date:** [January 18, 2018, 11:06pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/5 "2018-01-18T23:06:54Z")
Was it just sour or was it curdled and chunky? Sour milk can be (relatively) safely used in a number of ways. Or, take it back to the store. Then it’s their problem. And you get a refund! ---
**Author:** ![Ornery\_Bob](https://avatars.discourse-cdn.com/v4/letter/o/da6949/32.png) [@Ornery\_Bob](https://boards.straightdope.com/u/Ornery_Bob)\ **Post date:** [January 19, 2018, 3:52am UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/6 "2018-01-19T03:52:09Z")
**_Or pour it into the street gutter, which goes into the LA river_.** Not only is this the opposite of responsible waste disposal, it’s illegal. The _only_ thing that belongs in gutters is rain runoff. The parts of milk that aren’t water are not going to hurt your lawn. Even if it had chunks of curds in it, they would break down very quickly and not be a problem. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [January 19, 2018, 4:11am UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/7 "2018-01-19T04:11:13Z")
Feed it to the pets in your household. Feed it to the humans in your household: - Sour milk can be used instead of buttermilk in many recipes. - there are lots of recipes that use sour milk in cornbread, sour milk biscuits, scones, spice cake, pancakes, etc. - cheese, especially cottage cheese, can be easily madesour milk. - just google for sour milk recipies – you’ll get lots. ---
**Author:** ![Ornery\_Bob](https://avatars.discourse-cdn.com/v4/letter/o/da6949/32.png) [@Ornery\_Bob](https://boards.straightdope.com/u/Ornery_Bob)\ **Post date:** [January 19, 2018, 4:11am UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/8 "2018-01-19T04:11:13Z")
I’d also like to add that I fish the area near the Queen Mary (it’s at the mouth of the LA River) regularly and the amount of trash that comes down after a rain is staggering, not the mention the chemical waste which is why the fishing piers all have signs warning against eating the fish you might catch. People are polluting the LA River and the ocean around it just fine, they don’t need your sour milk adding to the bio-load. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [January 19, 2018, 5:07am UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/9 "2018-01-19T05:07:48Z")
Pouring it down the drain was perfectly okay; I mean, what do all of us put in toilets multiple times a day? Why do you buy your milk in 2-gallon containers if you can’t use it all? Or place it in smaller containers and freeze it? ---
**Author:** ![ManassasReader](https://avatars.discourse-cdn.com/v4/letter/m/c68b51/32.png) [@ManassasReader](https://boards.straightdope.com/u/ManassasReader)\ **Post date:** [January 19, 2018, 9:04am UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/10 "2018-01-19T09:04:33Z")
Is this a serious question? ---
**Author:** ![Richox](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@Richox](https://boards.straightdope.com/u/Richox)\ **Post date:** [January 19, 2018, 11:05am UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/11 "2018-01-19T11:05:04Z")
Depending on what your city does with the organic content of the water water, the drain might be the best option. For example, the organic waste in my cities major waste water treatment plants is processed using chemical, mechanical and biological methods and methane gasses are captured and burnt in a gas turbine to generate power. Solids are sold as chemical feedstock or for agriculture. Pouring that quantity of dairy into a normal compost bin would likely attract rodents and pests so isn’t ideal unless you don’t care about that. Pouring it on your lawn and diluting with water would have negligible impact on your lawn, good or bad. I doubt it’d be bioavailable for grasses if directly used. Of course all the above methods are totally incremental and it’s more of a thought exercise than anything else. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [January 19, 2018, 1:40pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/12 "2018-01-19T13:40:26Z")
> [@t-bonham@scc.net](#): > > Feed it to the pets in your household. Not a good idea. Most pets are lactose intolerant. ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [January 19, 2018, 2:51pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/13 "2018-01-19T14:51:29Z")
Thanks for the replies, everyone. > [@Mangetout](#): > > You could pour it out in a bowl and leave it to curdle completely, and dry out, then become infested with maggots - those maggots would turn into flies which are food for spiders, birds and small mammals. The leftover residue could be added to the soil around plants to nourish them. The local rats, cats, raccoons, coyotes, and skunks would surely appreciate the hand-out. > [@araminty](#): > > Was it just sour or was it curdled and chunky? > > Sour milk can be (relatively) safely used in a number of ways. > > Or, take it back to the store. Then it’s their problem. And you get a refund! Just sour. I’ve cooked with sour milk before, but only in small quantities. I don’t think taking it back is an option–it was fresh when I bought, it’s not their fault we didn’t consume it in time. > [@Ornery\_Bob](#): > > **_Or pour it into the street gutter, which goes into the LA river_.** > > Not only is this the opposite of responsible waste disposal, it’s illegal. The _only_ thing that belongs in gutters is rain runoff. Yeah, I know. But milk is a lot less harmful than other gunk that gets sent down the river. Being so easily bio-degradable, what part of the milk actually harms the river system? > [@nearwildheaven](#): > > Pouring it down the drain was perfectly okay; I mean, what do all of us put in toilets multiple times a day? > > Why do you buy your milk in 2-gallon containers if you can’t use it all? Or place it in smaller containers and freeze it? Well, similarly to the storm sewer only supposed to have rain run-off, the sanitary sewer is only supposed to have human waste. Other things increase the cost to clean the water. But, again, milk degrades so quickly, I’m not sure what the harm actually is. The two-gallon boxes at the wholesale club are almost the same price as a single gallon at the regular grocery store. And we typically use most, if not all, of it. But sometimes we don’t. I probably pour a whole gallon maybe three times a year, and smaller portions twice as often. > [@ManassasReader](#): > > Is this a serious question? The formal term is _Gedankenexperiment_. In this case, it is based on a real-life scenario, in which I want to consider the ramifications of my choices. > [@Richox](#): > > Depending on what your city does with the organic content of the water water, the drain might be the best option. For example, the organic waste in my cities major waste water treatment plants is processed using chemical, mechanical and biological methods and methane gasses are captured and burnt in a gas turbine to generate power. Solids are sold as chemical feedstock or for agriculture. > > Pouring that quantity of dairy into a normal compost bin would likely attract rodents and pests so isn’t ideal unless you don’t care about that. > > Pouring it on your lawn and diluting with water would have negligible impact on your lawn, good or bad. I doubt it’d be bioavailable for grasses if directly used. > > Of course all the above methods are totally incremental and it’s more of a thought exercise than anything else. I’m favoring the lawn treatment, but I’ll have to look up what my municipality does with sewage. My concern with giving it to the lawn is that the acidity or nitrogen content of the milk might damage it. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [January 19, 2018, 2:55pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/14 "2018-01-19T14:55:45Z")
> [@Pleonast](#): > > Well, similarly to the storm sewer only supposed to have rain run-off, the sanitary sewer is only supposed to have human waste. Other things increase the cost to clean the water. erm, kitchen sinks? garbage disposals? I mean, full marks for being considerate of your actions, but sanitary sewer and water treatment systems are well equipped to handle food waste. ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [January 19, 2018, 3:01pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/15 "2018-01-19T15:01:11Z")
Nm ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [January 19, 2018, 3:28pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/16 "2018-01-19T15:28:57Z")
In some circumstances, milk is a good plant nutrient. The specific situation I’m aware of is tomatoes. They can develop a calcium deficiency that manifests as fruit spoilage ([blossom-end rot](http://vegetablemdonline.ppath.cornell.edu/factsheets/Tomato_BlossRt.htm)). Watering tomatoes with dilute milk (even sour milk) helps provide calcium and prevent this rot. I don’t know if there are other nutrient deficiency diseases that watering with milk can help, but at a minimum it’s not harmful and “free water” and nutrients for the yard or garden. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [January 19, 2018, 4:22pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/17 "2018-01-19T16:22:23Z")
[This site](https://www.gov.uk/guidance/how-food-businesses-must-dispose-of-food-and-former-foodstuffs) and [this site](http://www.dssmith.com/recycling/insights/blogs/2016/1/pouring-milk-down-the-drain-is-a-criminal-offence-for-businesses), both in the UK, say that it’s illegal for businesses to pour spoiled milk down the drain. The second site says, “You may not know it, but milk is a highly polluting substance which is why it has been classified as 3 ABP [animal by product]. Milk is particularly harmful because of its high oxygen demand as a result of the bacteria that feed on it. This uses up oxygen that is otherwise used by fish and other living things in the watercourse – effectively suffocating aquatic life.” I remember an article that a local supermarket (here in the US) got into trouble for pouring spoiled milk down the drain. I assume it was a large quantity, like many gallons worth. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [January 19, 2018, 7:36pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/18 "2018-01-19T19:36:09Z")
> [@Pleonast](#): > > Well, similarly to the storm sewer only supposed to have rain run-off, the sanitary sewer is only supposed to have human waste. Other things increase the cost to clean the water. But, again, milk degrades so quickly, I’m not sure what the harm actually is. There’s really not much extra cost to clean 2 extra gallons of milk in a typical town’s sewage plant, as long as the plant is below full capacity. From the plant’s point of view, spoiled milk is pretty close to human poop (more fat, which could cause problems at high amounts, but otherwise fairly close); the only issue is how much there is. Since the plant is most likely processing millions of gallons a day; the extra two gallons won’t matter much. Now, a factory or something dealing in large quantities certainly could cause problems if the sewage treatment plant isn’t ready for it. In the U.S., you’d need a permit from the treatment plant to put commercial amounts of spoiled (or unspoiled, for that matter) milk into the sanitary sewers (and the plant could well refuse a permit, if they don’t have the capacity to handle it). But there certainly are such permits; I don’t understand why the UK site Dewey Finn links to has such a blanket prohibition. Putting milk down a storm drain, that dumps rainwater into a nearby stream, is very different and never OK. Environmentally speaking, the better solution is using it as animal feed – that way less fossil-based fertilizer and tractor fuel is used. Not exactly practicable for most people with two gallons, but this was mostly an intellectual exercise, right? Second-best is composting and using the compost to replace chemical fertilizer. With a home compost, odor could be a problem, but that’s only an aesthetic issue. A commercial composting facility might have issues with the amount of liquid but I think should be OK (the one I know of even takes meat with the bones). Spreading a couple gallons on the lawn should I think be nearly as good, assuming it’s not all washed off by a rainstorm that afternoon. Just dumping it in the woods somewhere would also work (in small amounts) Third best probably is down the toilet. The sewage plant may end up making some compost, but there is a cost for that (again, pretty minimal for two gallons), and putting it straight to compost would get more useful yield at less cost. Again, large amounts needs permission from the sewage authority. Fourth best is a landfill that collects methane. Fifth best is a good landfill. Worst is pouring down the drain in the street outside, which is essentially pouring it into the nearest stream. Smelly and causes dead fish. ---
**Author:** ![Brayne\_Ded](https://avatars.discourse-cdn.com/v4/letter/b/e9bcb4/32.png) [@Brayne\_Ded](https://boards.straightdope.com/u/Brayne_Ded)\ **Post date:** [June 23, 2018, 3:17pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/19 "2018-06-23T15:17:05Z")
> [@Richox](#): > > Pouring that quantity of dairy into a normal compost bin would likely attract rodents and pests so isn’t ideal unless you don’t care about that. > > Pouring it on your lawn and diluting with water would have negligible impact on your lawn, good or bad. I doubt it’d be bioavailable for grasses if directly used. Compost - no problem. It is meat that attracts rodents and pests. Sour milk will be bioavailable. Onto the lawn? No problem. Just spray some water over it. Or pour it into a flowerbed. Why increase the BOD in the sewage plant by pouring it down the drain? ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [June 23, 2018, 4:53pm UTC](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925/20 "2018-06-23T16:53:38Z")
I suspect a good portion of the OP’s milk is not pourable at this point. 😉 [Next page](https://boards.straightdope.com/t/environmentally-friendly-disposal-of-spoilt-milk/806925.md?page=2)