Resurrecting the California Cooler

Coastal Northern California is blessed with a very moderate climate, generally on the cool side, especially at night. Before the refrigerator became common in households, denizens of this region took advantage of the cool weather by storing perishable foods in a special kitchen cabinet that brought in air from the outside -  the "California Cooler."

When the refrigerator came along, it seems that, over time, the vents were boarded up and the California Cooler was all but forgotten. Today, if you walk the streets of my hometown, Berkeley, where most of the houses were built in the 1920's, you will see many homes, and even apartment buildings, with the exterior vestiges of these vents.

My house is such a house. When we decided to remodel our kitchen in early 2009, I came up with the idea of opening the vents and bringing our California Cooler back to life. What better way to conserve energy in this age of green thinking than to keep foods cool with outside air? This is the story of the resurrection of a California Cooler.

Step 1 History of the California Cooler

Most of the information I have found on the Web about California Coolers consists of blogs dealing with kitchen remodeling.. This blog (petchhouse.blogspot.com/2006/10/california-cooler-problem.html) has some interesting information. The author says that the California Cooler came into existence in 1910, not in the 19th century as I would have thought. I may have to go to the library to find out more about the history. Below are a few more interesting links that I've found.

blogs.kqed.org/bayareabites/tag/california-cooler/

cityhomestead.wordpress.com/2008/08/

forum.arts-crafts.com/eve/forums/a/tpc/f/4706079532/m/736109141

In this link someone is remodeling their kitchen and debating whether or not to keep the CA Cooler www.thathomesite.com/forums/load/kitchbath/msg110319387697.html

californiabungalow.blogspot.com/2009/07/cooling-cupboards-part-of-bungalow-kit.html

Below is a gallery of California Cooler photos that I shot in South and West Berkeley, actually photos of the exterior vents which, presumably, are all boarded up. They are VERY common around here and the majority of them seem to be floor-to-ceiling pantries. Our single, large vent seems to be very unusual.

Comments

[scaffnet]

OMG - just read this:

"I have started doing little things to make our fridge not work as hard. For example, when I cook a big pot of soup, I let it cool down to room temperature until putting it in the fridge. Sometimes I'll leave something out overnight (if it doesn't have a smell that would attract animals) and then put it in the fridge in the morning, shaving off the amount of cooling the fridge needs to do on that item."

You understand you are playing Russian roulette with microbes by doing this right? You may end up making your fridge work less but your guts work more to expel food that has spoiled.

Food is at high risk for spoilage if it is held at temperatures between 40 and 140F for longer than 2 hours.

[dlginstructables]

I appreciate your comment, but I think this is a debatable point. To my knowledge, I have not had food poisoning or any problems with spoiled food. I think in general people overdo it with refrigeration. When you say food is at risk for spoilage between 40 and 140 F for longer than 2 hours, that can't possibly be true as a general statement. Think about it - people bring sandwiches to work for lunch all the time and have them at room temperature for several hours. Each food needs to be treated on a case by case basis and by challenging our notions about refrigeration, we can use a little less energy for that purpose. Eggs are one of the best examples. Everyone keeps eggs in the fridge and my experience says that they do just fine at California Cooler temperatures for long periods of time.

[scaffnet]

It is not debatable, it's science.

Plenty of foods provide a perfect habitat for the growth of microbes between 40 and 140F.

Below 40 and growth is slowed or halted. Above 140 they can't survive - although some newer strains of e. coli have been shown to be very heat and pressure tolerant, which is cause for concern.

"There are two completely different families of bacteria: pathogenic bacteria, the kind that cause food borne illness, and spoilage bacteria, the kind of bacteria that cause foods to deteriorate and develop unpleasant odors, tastes, and textures.

Pathogenic bacteria can grow rapidly in the "Danger Zone," the temperature range between 40 and 140 °F, but they do not generally affect the taste, smell, or appearance of a food. In other words, one cannot tell that a pathogen is present. "

http://www.fsis.usda.gov/factsheets/refrigeration_&_food_safety/index.asp

When you are dealing with dairy, meat and beans it is entirely foolish to disregard safe storage temperatures, whether the food is raw or cooked.

For example, restaurants are required to take soups down to below 40 as quickly as possible before storing it in their coolers. They do this by putting the pot in a sink full of ice and water and stirring the soup until it is cool.

I'm a serious home canner. I have a root cellar. And I have been in the restaurant business for years. So I understand there are plenty of foods that don't need refrigeration.

However, "challenging our notions about refrigeration" is not sound advice, especially when you are coming at it from energy use biases, which have nothing to do with food safety.

[scrutables]

I'm a serious biologist. I have a lab, where I grow bacteria for a living. And I sez that advice like this is why our society is over-sanitized. In order for pathogens to grow in food, they have to show up in the first place. In the case of a pot of soup, if it's covered while hot that won't happen. In the case of eggs, they are already sterile little globes that do a really good job of keeping pathogens out, because that what the growing embryo needs. The restaurant business has plenty of rules that should never apply to home kitchens (are your sponges soaking in a tub of disinfectant at your house?). And canning is the process of rendering something sterile so that it can be kept totally unrefrigerated for months at a time. For perishables that will be eaten within days, there are many fewer issues.

I love this idea! If I owned instead of rented, I'd be doing it now. As it is, my kitchen and pantry are unheated, and we keep lots of food out of the fridge. It's great! Great job, dlg!

[revolushn]

I keep my eggs in the cupboard. I thought everyone did..

Love the idea, no houses i know in New Zealand ever had these coolers though, and I'm not about to knock a hole in my rented property :D

[scaffnet]

You can do whatever you want with your own food. I'm certainly not a zealot about cleanliness and procedures in my personal kitchen.

But to suggest that the growth of pathogens in food is "debatable" is borderline irresponsible.

And for a "serious biologist" to suggest that a covered pot of soup is an acceptable safeguard against pathogens is downright laughable.

Here's a scenario for you. You make the soup. You cover it and put it on your counter to cool (which in itself is a bad idea, as you are now keeping it in the danger zone even longer by trapping in all that heat with the lid).

A family member takes some some with a ladle and puts the ladle on the counter, where it picks up some critters. You come back in later to stir the soup with the same ladle, which inoculates your perfect growth environment (AKA "soup") with said critters.

Maybe some bad critters will grow. Maybe something unpleasant will happen when you eat the soup, maybe not. But why take the risk? Is your bathroom that awesome a place to hang out?

[ravenwing999]

In every restaurant I worked in, cooked food was ALWAYS cooled to room temp. before refrigerating it. They were very large pots and pans and took quite some time to cool. The only exception to this was if it was closing, food was put into the cooler before locking up.

[keng]

I think that America (for some reason though I probably lean more towards bad law-makers and good (that is deceitful) lobbyists) has had some things beaten into us rather than proven to us. If you take a look around aka Germany, New Zealand, and Britain, eggs are kept at room temperature in the stores where they are stacked in an isle and sold.

I think we need to rethink our 'danger' zones and food handling methodologies. I think some maybe over regulated in order to get people to at least comply with a lessor standard that wasn't being adhered to before the more restrictive regs were put in place.

[Pilgrimm]

Absolutely Correct!!

I am certified in the state of Connecticut as a licensed Food Handler, and what ravenwing is doing is creating the textbook perfect conditions for the creation and propagation of C. Botulinus, and Salmonella, as well. This practice is extremely hazardous!! One airborne spore, allowed to enter this food medium at temperatures between 40 degrees and 160 degrees Fahrenheit, and then sealed anaerobically, will kill your entire family, if it doesn't blind them first. If you doubt what I say, I suggest you use your little computer to research the local Public Health website in the town you live in. And she can tell every restaurant she ever worked in that the management is literally endangering the lives of every customer! That is, if you believe her claim, which I certainly do not. This is not a joke, this is a very serious, life- and death- matter!!

[Calorie]

Most of the countries you mentioned have very cool clients. I lived in various parts of the UK, and some people did put their eggs on the shelf. But the interior of our house was kept at 60F or so. Student poverty and such...

Refrigeration was a massive improvement in public health safety. Before mechanical refrigeration they use to haul enormous blocks of ice down from the Northern America and kept it insulated with straw. In the old UK structures (as in the middle ages) they had ice lockers.

I have no idea as to why someone would take a chance with something that is so elementally obvious.

Food Refrigeration is ubiquitous for a reason. It allows for food to be kept safer and cheaper than non-mechanical designs. Cheap and safe. Like seatbelts. It only takes one time. The odds of being in a car accident in a lifetime are pretty good, particularly in New Zealand.

It only takes one time for something to go seriously wrong. Bohemianism is not a fun way to die. The mechanism of death is basically the same used in various chemical weapons.

[lourens01]

I am reading this and cannot help to think back at some things I have seen over the years.

In 1989 I saw people selling meat in Namibia. A whole carcass, in the sun, at about 38 degrees Celsius. That is really hot. It took then 4 days to sell everything. When they grab hold of the carcass to cut a piece of, the area around it turns black because of the flies that were sitting on the meat.

I did not buy any of that meat for obvious reasons, but it sure goes a long way in proving that modern day thinking in terms of germs and sterile environments might be a bit over the top.

I do not say that we should leave meat out in the open, but I do think we can leave more things unrefrigerated.

[gumbytig]

A few comments to fuel this fire. First, if the food is cooked (ie. soup) above 140F and the lid left on for that time, the microbes (ignoring heat resistant strains) are all dead. If that container is left closed before cooling into the "danger zone", the inner contents should be sanitized (not sterilized) well enough to cool outside prior to refrigeration. Second, being outside means that there is better airflow around the the container to provide quicker cooling than just sticking the item in the fridge (what most people do rather than water bath it while stiring) where there is little to no airflow unless you have an industrial fridge with an air circulating fan that runs all the time. Third, "danger zone" and all this other guide lines are overprotective by nature since there is a difference between leaving a pre-boiled pot of veggie soup covered and outside in 45F temps for a couple hours and leaving an open container of mayonaise out on your counter on a humid 80F day. All the guide lines are meant to be a suggestion for best chance of never getting a food spoilage illness. By the way, i'm a home brewer. I take a sugar rich substance and leave it at about 65-70F (sweet spot of the "danger zone" for yeast) for 6-12 hours before the yeast take hold and provide a carbon dioxide layer on the wort protecting it. Which goes back to my first point of sanitizing the contents and container and keeping a closed system.

[JermsG]

I've seen a few of them in various rental properties in NZ. My father calls them a meat safe, like those camping food-storage things you hang from trees.

I've always found those egg-holder things in the doors of fridges to be uselessly small; the eggs always fall out when you open the fridge. I've kept my eggs on the bench for years. Um. Not the same eggs the whole time, obviously. But they each last a month or so quite happily.

[Tizme]

Safes were commonly installed in homes in NZ in the past and were still fitted in The State houses right up through the '50s (Kawerau, Meremere, etc). Early ones were a wall mounted cupboard as previously described. The later ones had a "fly screen wire" covered vent through the floor at the bottom of a set of 3 vertical cupboards with the shelves in each made of 3'x3/4" slats with gaps.Another vent either to the outside or the roof space ensured air flow. They were used for fresh vegetable storage(and eggs). Most homes had refrigerators too. As a country kid in the 40's my mum also had a meat safe hanging out in the cooler 'tank shed' but the meat was never in there for long. However Dad was a keen deer stalker and I remember a hind quarter often hanging out there too. A chunk of meat was sliced off and the rest left there in a muslin bag (to keep flys away). He is now in his 90's so maybe we had tougher guts in those days.

[Taranach]

OMG!! How did our ancestors ever survive all those centuries without a refrigerator to preserve their food...

While it is true that there are "optimum" temperatures to reduce risk factors, there is a difference between observing due caution and outright fear-mongering. There is also quite a bit of difference between the regulations for a restaurant that serves hundreds of people a day and a private residence. Make sure you understand these differences before making blanket statements condemning a private party under commercial regulations.

Then there is the further fact that most refrigerators operate between 35 and 41 degrees Fahrenheit... interesting that the high end temperature of a "normal" fridge is within the very spec that you claim is so very hazardous.

[Taranach]

I see... so the restaurants are required to break the surface of the soup and stir in possible pathogens during the cooling process... remember there is a human breathing right above that soup while it is being stirred... If that actually *is* a regulation, then I really must challenge it's efficacy.

It is slowly being discovered that our very aversion to germs and our futile fight to eradicate them from every aspect of our lives is also robbing us of our natural ability to fight off many of these germs. Our immune systems actually become stronger only with contact with various germs and our dependencies on antibiotics only leaves us less able to defend against germs and stronger and more virulent strains.

[rpb]

There is also a big danger of heating up EVERYTHING in your fridge if you put pots of uncooled items in there, which risks spoiling ALL OF YOUR FOOD, so given the choice I generally let foods cool outside the fridge and put them in when fairly cool.

And it's not like the hot thing you are putting straight into the fridge is going to cool to 5C immediately anyway (while it's heating everything else up!).

[soundmotor]

I like the cut of your jib sir.

[soundmotor]

I'd hate to be one of your children.

[Pilgrimm]

In order to prevent "heating up" the entire contents of the fridge, restaurants, caterers etc., often sit a large pot of hot food in an ice bath, stirring frequently, to reduce the temperature quickly, and maintain food safety. You can find large polyethylene "coolers" in restaurant supply catalogs which are sort of like a large jar with a round bottom, not intended to be free-standing, but for suspension in a large stock pot full of hot soup. The "cooler" has a screw-top, and is filled with ice, and then dropped into the pot, cooling it rapidly! If godforbid the ice should melt, replace it with some more!

Too many people in here putting absolutely one point of view ahead of modern, common practice. One lady wants to kill her family, and another fella says its her right to do so..... Try thinking a bit before engaging tongue, and allow for a different, maybe even safer method!

[rpb]

> Too many people in here putting absolutely one point
> of view ahead of modern, common practice.

That's your one point of view...! And that might also make sense if this were a discussion amongst restaurateurs, but this is instructables, and most people commenting here are home owners doing home cooking.

None of us will have "ice bath cooling apparatus", and it is unreasonable to expect any of us to have such things. They are also unnecessary for home cooking.

I admit that sometimes, for speed, I will put a very large pot of fresh soup in a sink of cold water to cool it down more quickly before putting it in the fridge, but apart from that there is no particular danger from allowing recently-boiled soup to cool, covered, for a few hours before putting it into the fridge.

In addition, since we are home cookers with domestic refrigerators, it is not safe to put hot items into a domestic fridge because it WILL heat up other neighbouring items for some time, some of which may have been in the fridge for a while, and some of which may get heated up several times, each night, when hot items get placed into the fridge.

Let the fridge do its job - keeping cool things cool. Just be sensible with the rest - let food cool before you refrigerate it. And if it will cool slowly (large pots or very hot weather) or may already have a short shelf-life (items not recently boiled) then try to cool it quickly, refrigerate it promptly, and then keep track of how long things have been in your fridge!

[Pilgrimm]

"In every restaurant I worked in, cooked food was ALWAYS cooled to room temp. before refrigerating it."

"so the restaurants are required to break the surface of the soup and stir in possible pathogens during the cooling process... remember there is a human breathing right above that soup while it is being stirred... "

"Refrigeration was a massive improvement in public health safety. Before mechanical refrigeration they use to haul enormous blocks of ice down from the Northern America and kept it insulated with straw. In the old UK structures (as in the middle ages) they had ice lockers."

"It is slowly being discovered that our very aversion to germs and our futile fight to eradicate them from every aspect of our lives is also robbing us of our natural ability to fight off many of these germs. Our immune systems actually become stronger only with contact with various germs and our dependencies on antibiotics only leaves us less able to defend against germs and stronger and more virulent strains"

I don't really disagree with anything being said here, on an individual basis. Treat your food anyway you wish. I can refuse to eat it if I wish. When ravenwing made the first quote above, it started getting a bit scary. Botilinus toxin DOES exist, it IS FATAL, even Al-Qaeda knows that. Ravenwing never saw the owners of every restaurant she ever worked in follow poor food-handling procedure. The majority followed safe procedure, she just wasn't paying attention, I'm sure!

In closing, (I hope...) The chances of poisoning yourself or a whole congregation are relatively small. But there were a few people making some VERY broad statements I thought it important to refute. The long & short of it is, do what you want. Don't bother me if you get a bellyache!

OK?

[grannyjones]

Food safety trumps energy savings.
Refrigeration has probably saved millions of lives
that would have been lost due to food poisoning.
Just think,"What is cheaper--take a chance on iffy food
versus a trip to the E.R.--or a funeral?
It's a no-brainer. Please be safe.

[twighahn]

could u explain more clearly how this works.what makes the air cooler in the cc

[dlginstructables]

What makes the air cooler is the climate where I live. Even in the summer, the temperature usually goes down into the 50s at night, so by having the CC vented to the outside, we can take advantage of that cooling effect. I also cool down a couple of 1 gallon jugs of water by placing them outside at night and then I put them in the CC in the morning. In the winter, the CC works even better, because it stays cool during the day also.

[twighahn]

up in the appalachians they used to put a cold house over the river that was closest to the house.there was no floor so the cool air from the river kept the cold house cold inside even in the hottest of days.the lower part of the cold house nearly froze some foods so u had to keep that in mind when stocking it

[carlaashton80]

I grew up in southwestern PA, and a lot of the old farms had spring houses. You'd build a little house around a natural spring on your land and run the water through a small trough. The spring houses were usually built out of stone or brick and the interior stayed nice and cool. If something had to stay really cold, you'd put it in the trough and let the water run around it.

[csprinkle]

I live in Mexico, where eggs are NOT refrigerated in the supermarkets. I lived in France, where milk is not refrigerated in the supermarket and it was not the ultrapasteurized variety.
Prime beef is hung to age for unrefrigerated.
In the US too much is made of "cleanliness". Use common sense. I know people who refrigerate EVERYTHING. I also know people who spray everything they touch with Lysol. We build immunity by coming into contact with "germs". That's not to say, we should touch and/or eat everything, but still....just use common sense!
People are afraid to leave anything with mayonnaise out (particularly potato salad), but it's not the mayo doing the harm (unless it's homemade mayo, and honestly most people buy it, don't they?) It's the POTATOES that are the danger...they have a high water level and can grow bacteria much faster than commercial mayo..

[dacarls]

This Calif Cooler system is excellent. How about extending this method to remove refrigerator heat from the kitchen? Women always complain about heat in the kitchen.. (no flaming please, honey, I'm trying to help). If you stand near the back of the fridge, heat is pouring into that room, i.e., the kitchen. Every bit of warmth pulled out of the fridges' contents is jammed into an already warm room.

I have never seen a system to remove this waste heat and vent it outdoors, to the attic or maybe even somewhere else in a house where dry heat is needed. Bathroom? Laundry? Some enclosure would be needed, maybe not much, but even a small muffin fan would do the job. Expel this heat source outside thru the California cooler vent!
Cmon engineers. somebody do this......

[aardvark]

What temp does it average in summer?

[dlginstructables]

Lately, around 65 F

[inalak]

This is a pretty awesome instructable. Wish we could make use of this idea but where i live in Hawaii it's NEVER that cool :P

[oakironworker]

Great job. Don't listen to the boys who live in a bacteria free bubble

[evanfriesen]

My parents have a freezer in their garage. In winter...4 months of the year... the temperature is consistently below freezing. They still keep the freezer running though...I suspect it is to keep the food warmer than the temperature in the garage. This seems like them.

I dig this instructable though. Very cool.

[Antipassifist22]

I <3 scientific flame wars

[davidkichi]

Cool project! I learned something new! Have heard of Koreans burying their jars of kimchi in the ground during winter but never this. I've always wondered if people in the midwest, eastcoast or up north where it snows would unplug their fridges during winter since it wouldn't make sense to use electricity to create cold temps to chill or freeze food when nature can do it for you. SF,CA dweller here.

[Dude567]

 try this, hang a damp towel on the outside vent, the sun evaporates the water and the air is cooled. Just keep the towel wet with a small drip from a plastic water bottle

[dlginstructables]

Thanks for the idea. I'm thinking that it would be better to have a set of hanging strips instead of a solid towel, so that air could flow through it better.

[soundmotor]

Growing up in the San Joaquin valley, one heard the term "swamp" cooler quite a bit . It may not be as effective in SF because the relative humidity needs to be low.

http://en.wikipedia.org/wiki/Evaporative_cooler

[jeanicrowe]

Use burlap or even a loosely woven mat. Rather than a plastic bottle, how about a length of tubing with small holes poked strategically along its length so the water source is continuous. Also, living in a very cold winter climate, I'm thinking of digging a 'well' that I can flood with successive layers of water, letting each freeze, with a dumb waiter type of arrangement i can lower into it to keep food cold. I know it will work in the winter, might get too cold, even. But I wonder, if the 'well' is thickly insulated, how long the ice would last into the summer? My Dad and his family cut ice blocks in the winter and stored them in a shed insulated with straw and they kept into July, sometimes longer. They cut big blocks that they stacked tightly. They also used a spring house and kept the butter and milk in a box that they lowered into the well. I don't think it was in the water, but just above it.