As you may have noticed, I am an absolute omnivore: I eat everything! Moreover, I enjoy eating everything. Well, I should say almost. There is one very commonly use ingredient that I just can’t stand: cilantro (or coriander). How many times have I been disappointed after ordering what sounded like a delicious dish when I found out it was soaked in cilantro. As I read in this blog it seems that I am not alone. Also there seems to be a scientific explanation as to why it tastes to me like perfume (see this article in the New York Times) as apparently it does share a lot of its components with those used in perfumes or produced by some bugs. So I was wondering, how do you guys feel about it? Time for another poll!

NOTE ADDED: I forgot to mention one thing. Please, please, cook of the world. Cilantro is not a very common ingredient in Spanish cuisine (I mean from Spain, not other Spanish-speaking countries) and gazpacho should definitely NOT contain any of it!


Last week I shared with you the kitchen experiments I have had most fun with during this year but, what about you guys? Which one was your favourite? Here is a list of all the experiments we have done together this year:

Time for another poll! You can chose up to 3 different experiments. Which ones did you enjoy the most?

The other day we celebrated the first anniversary of this blog by reviewing the top 5 most read posts, today I want to share with you the top 5 experiments I had the most fun doing in my kitchen in the past year. Here it goes.

– Make your own snow

This experiments would rather have been in the top 5, had I actually been able to do it, but I failed :(. I’ll have to try again next winter.


5. Make your own butter

Easy and very tasty experiment! You can also make delicious flavoured butter this way. Yummy!

4. Chocolate is like Gremlins

As a good chocoholic, this was one of my favourites. Also, it was the first one!

3. From liquid to solid in a punch / in a step (or a scream)

The Physicist inside me very much enjoyed this rare phase transition. Fun!

2. Microwave experiments:  Make your own plasma/Cooking light bulbs

Who knew one could do these things at home?

1. Naked eggs

My absolute favourite! It does take a few days for to strip the eggs but it is totally worth it! Also a really good way to explain osmosis in a science class.

I know, time flies: The h bar is already one year old! Despite the slow down in my posts in the last few months due to too many things going on in my life at the moment, I have had the most wonderful time writing this blog. I’ve had lots of fun experimenting in my kitchen and, most importantly, I have had many interesting discussions with friends who keep suggesting things to try for the blog, lending me amazing books and sharing lots of kitchen moments. So, the biggest thank you to everyone who has contributed to this blog in one way or another, this is indeed the result of a team effort :).

I have posted so far 34 blog entries and I thought that a good way to celebrate this anniversary would be to review some of them. Today I want to share with you the list of “most read” posts of the blog and in my next post I will share my personal favorites.


5. From liquid to solid in a punch

This experiment is fun to do! And so easy: all you need is water and corn flour (also known as maicena or cornstarch). Highly recommended. Get your hands dirty and experiment a rare phase transition induced not by a change in temperature but by a change in pressure.

4. Cooking with salt and vinegar

Here I tried to understand what we mean by “cooking” and how one can do it not only using heat but also using other things such as salt and vinegar.

3. Gels: two for one

I had no idea what a gel really was before this. This post tries to be a pedagogical explanation of how a solid and a liquid co-habitate a gel to give it its characteristic consistency.

2. Why does bread go stale

Why and, most importantly, how can we avoid it. Easy tips to keep your bread fresh for a little while longer and why they should work.

1. Why you shouldn’t put chocolate in the fridge

They say that sex sells but let me tell you something: chocolate also does! This is the most read post during this year,  a very  controversial topic: putting or not putting chocolate in the fridge, that is the question. I also asked the readers in a poll in December and, so far, “no” wins by 58%! Chocolate lovers, spread the word: if it’s too hot for chocolate just have a chocolate ice cream but please, please do not store chocolate bars in the fridge!

Some weeks ago I posted a link to a video of the BBC program “Bang goes the theory” which explained why cream whips. In passing, it also showed how butter is done. It looked so easy that I decided to give it a try myself and it was indeed as easy as it looked!

By the way, “Bang goes the theory” is back again on Wednesdays at 19.30 on BBC One.

Back to our butter. All you need is some double cream and a mixer. Actually, in another BBC program “Jimmy’s Food Factory” he did it without a mixer, by just shaking the cream in a jar. But if you appreciate your wrists, I do not recommend this :S.

We start with the double cream in a tall glass to avoid spilling. Cream is an emulsion of water and fat. Normally, as we know, water and fat don’t mix. They need the help of an emulsifier to do it. This is a molecule that gets attached to water on one hand and to fat on the other, helping them mix together. It has to be double cream because single cream does not have enough fat to be whipped.

Double cream in a tall glass

We start whipping, ideally with a mixer and after a few seconds we see it rising and making a thick foam. What we are doing is inserting air bubbles into the mix. The fat molecules wrap these bubbles protecting them and keeping them from bursting.

Whipped cream

What happens if we keep mixing after this is that we start breaking the air bubbles. When one of them collapses, all the fat molecules around it come together making a big lump. All these lumps start coming together and the water is left out: we have reversed the emulsion! What we have now is a lump of butter floating in some white liquid called butter milk.

Butter and butter milk

Then just strain all the liquid out and you have made your own butter!

Separating the butter from the butter milk

Butter and whipped cream. Both from the same cream after different times of whipping

You can just enjoy it as it is on your bread, with some salt or you could even flavour it with your favorite ingredients: herbs, chillies, salmon, lemon and dill, you name it!

Home made butter!

I have waited to try this experiment for six months! Too bad when I first saw the video in YouTube I didn’t realize that one needs really cold temperatures for it too work. Despite the freezing days here in Europe in the past 2 weeks, it has not been cold enough for it to work in Edinburgh :(. Perhaps where you are it is cold enough (I hear it should be at least 0F, – 15ºC) so that you can try it and then send us a video of it!

For the time being let me just show you this YouTube video. The experiment is very simple: take a cup of boiling water, throw it up in very cold air and watch it freeze instantly and convert into snow!

The amazing thing is that, if you try it with cold water or just water that is not boiling, it won’t work. There seem to be two reasons for this. The first one is that boiling water may disperse faster in the air breaking into very small drops that freeze faster. The second one is the Mpemba Effect, which says that, under certain circumstances, boiling water freezes faster than cold water.

I find this effect fascinating, because it is so counter intuitive. Say we have two samples of the same amount of water inside 2 twin containers: one with boiling water and the other one with water at 25ºC. When put in the freezer, the boiling water has to first reach 25ºC and then freeze while the other recipient only has to do the second step. Clearly then, the second recipient will freeze faster than the one with boiling water.

This is so when both recipients are exactly in the same conditions but it turns out that they are not. First of all, the boiling water is loosing some water through evaporation at the beginning so, even if initially we put in the same amount of water, after a while it will have less water than its twin pot. Secondly the high temperature of boiling water could change the properties of the material that it’s in when heating it up: it may become a better conductor of heat and accelerate the cooling process. Also the convention currents in both pots will be different, presumably increasing the cooling speed in the boiling water one. Finally there are experiments that show that supercooling is favored in cold water versus hot water. Supercooling is an effect that occurs when water does not freeze at 0ºC but at a few degrees below 0.

Each of this effects are very small and separately could not cause an observable difference in the freezing time. However in some circumstances, the combination of all of them together seems to conspire in such a way that the boiling water freezes faster.

I found trying this experiment in my freezer quite hard because I think that opening and closing the door to check the samples influences it a lot. Then I tried doing it outside on a cold day, but it wasn’t cold enough and finally my Chemist friends tried doing it with dry ice and other fancy gadgets. Long story short: we have not been able to reproduce this effect.

It only happens for some very special initial conditions and, despite having played with the variables around, I haven’t been able to find the right set. In particular I would need to know how much water one needs to put in each container, what kind of material should one use and what should be the initial temperature of the non-boiling water. I found this video in You Tube where they manage to do it in their freezer:

I did try the exact same method and it didn’t work: perhaps my freezer does not reach the right temperature…

The challenge for you now is to try this at home and find the ideal set of initial conditions for it to work.

A colleague of mine has introduced me to this problem which combines mathematics and food. The challenge, as stated by George Hart, is to find three foods that do not go together well but every pair of them does.

In his statement of the problem, George Hart sais that they should not go well together “by any reasonable definition of foods going together”. But I think that this is so subjective that it would be almost impossible to agree on a reasonable definition for this. For instance, I have a bet with another friend in which I claim that if I like a given food alone then there is a way in which I can combine it with chocolate and still like it. However I realize that this wouldn’t mean that other people who are not chocoholics, would like the mix…

In fact, it is quite difficult for me to think of 3 foods that wouldn’t go together under any circumstance. So far, for every combination suggested in George Hart’s website,  I can find a way of cooking them or picking the right proportions such that the combination would taste good to me. But I guess some would say that I would just eat anything…

In that sense, it is even more difficult for me to think about the complementary problem: find 3 foods that go great together but such that every pair of them does not.

Even though I believe it is probably impossible to solve this because of difficulty in agreeing on what goes together well and what doesn’t, it is still a good conversation starter for a lazy afternoon and if you do come up with some ideas please post them in the comments of this post. I’d be happy to accept the challenge of finding a recipe that combines all 3 ingredients and eating it :).