Cooking With Molecules

I've mentioned my brief forays into Molecular Gastronomy, but haven't posted any of my stunning successes yet. Mainly because there haven't been any. If you read the blogs of people who dabble in this stuff, it seems the first thing everyone wants to try is Spherification, and I'm no exception. The basic idea is to create blobs of intensely-flavoured liquid encapsulated in a gel skin that melts when you eat it, leaving a 'taste explosion' in your mouth. The classic example of this technique is Ferran Adriá's olive. It looks like an olive, but tastes more olivey than any real olive ever could. It's also possible to make small spheres of your liquid, and they look like caviar.

The basic idea is to add a gelling agent (sodium alginate) to your strongly-flavoured liquid, and then carefully drop spoonfuls or droplets from a syringe into a bath of calcium carbonate dissolved in water. When the alginate meets the CC, it sets into a gel. So a skin is instantly formed on the outside, leaving the inside liquid, well, liquid. You only leave your blobs in the CC for 1-3 minutes (depending on their size) and then you take them out, rinse in cold water, dry on a paper towel and serve (or throw in the bin, in my case).

We had a load of apples and pears left over from Christmas, so I pulped them and then made a consommé of them using the gelatine freeze-thaw method. This technique requires you to melt some bloomed gelatine into your liquid and then freeze it overnight. When it's frozen, you place it in a filter paper (or cheesecloth) inside a strainer over a bowl and leave it in the fridge for 2-3 days until the liquid has melted and dripped through the filter. The gelatine forms a kind of web that grabs hold of all the solids, while allowing the liquid to drip through into the bowl. The resulting liquid is perfectly clear, with all the flavour and colour of the original goop.

I made some 'caviar' of apples and pears, and also some bigger drops, a bit like small grapes. I showed one to MamaDuck, who freaked out a bit and said she would never eat it (so no apple sauce gel blobs for her tonight!). Some of the early attempts looked like tiny fetuses, most of the bigger blobs were malformed with extra mini-blobs or tails stuck to them, but the caviar looked good.

The main problem I have with spherification is getting the right proportion of chemicals in the solutions. The quantities required are quite tiny (like 1.5 grams), and I have no way of accurately measuring such tiny amounts. My digital scales claim to be able to weigh increments of 1g, but really, they don't. So I need to get hold of some scientific scales, but haven't been able to find any yet.

On a related note, I've been getting a fed up with the unreliability of gelatine for the jelly in my pork pies. Sometimes it's difficult to inject enough jelly into the pies, and sometimes the bloody stuff just won't set. I tried an experiment a few months ago where I poured liquid jelly into the pie case before baking, but it just soaked into the pastry and the meat.

So I've been looking at Agar Agar. This substance is extracted from seaweed (so it's suitable for veggies), and has some interesting properties. The ones I'm interested in are the gelling point and the melting point. For a 2% solution of agar agar, these are 38 and 89 degrees C. And the temperature at which minced pork can be declared cooked is 71C, so in theory I could wrap the meat in a sheet of set agar agar jelly and bake it without it melting. Now that would be a super-terrific thing if I could do it. If it worked, I could also put a blob of set jelly inside my albondigas (meatballs) to reduce their density and give a zing of something different in the middle - it doesn't have to be meat-flavoured, even, it could be apple-flavoured. Nom nom.

I'm rambling. Today I went off in search of agar agar. I know I could get this from Manuel Riesgo behind Gran Vía, but I didn't want to go into the centre. I found some powdered agar agar in a local health-food shop, but at €6 a spoonful I thought it was a bit overpriced. But I did notice it came from China and that gave me an idea. There's a street in our barrio that's like a mini Chinatown, so I went up there. The first shop I went to is so jam-packed with stock that there's no room for customers, but I asked them about it and they pointed me at HP Sauce and cans of corned beef (obviously as a gweilo-guiri, what else could I want?). The next one I tried was much better. It was actually big enough to accommodate the massive range of stuff they sell and still leave room for customers. Nice. They did have agar agar, but only in 1-kilo packs about the size of a cushion. I asked them if they had smaller packs, and the guy disappeared upstairs and came back with a 42g pack for €1.40. Marvellous. It's a terrific shop, actually, packed full of mysterious stuff. They have a section at the back that has everything you need to set up a Chinese restaurant - woks by the million, crockery, sizzler plates, cook's clothes, cleavers, knives, chopsticks. And I also noticed they had 1-kilo jars of whole black peppercorns for €6, and stuff like Schezuan pepper salt and other exotica at insanely-low prices. I'll definitely be back there next week.

Anyway, gotta dash, got to play with my agar agar.

Cooking 2.0

In recent weeks I've become quite interested in what I think of as Cooking 2.0, but which the rest of the planet calls Molecular Gastronomy. In case you haven't stumbled across this, it's a method for high-profile chefs to make vast sums of money by serving miniscule portions of chemically-engineered food at staggeringly high prices.

The preparation of food, of course, has always been about chemistry, but most chefs are happy to just follow recipes without really knowing what processes are going on. The new generation of Cooking 2.0 chefs (Ferran Adriá at El Bulli near Barcelona, Grant Achatz at Alinea in Chicago, Heston Blumenthal at The Fat Duck in the UK and many others), use many techniques that are more at home in a laboratory setting to create astonishing gastronomic experiences. I haven't actually sampled any of these delights, I'm not made of money, and El Bulli only opens for six months of the year and reservations sell out on the first day of each season. So I guess I'll have to try making these things myself.

This all started, by the way, when I was trying to solve a couple of problems with my pies. One problem was how to stop pastry sticking to aluminium foil trays - butter works well, but has to be applied very carefully; oil is more hit and miss. I wanted something I could spray into the trays (you can get something called PAM in the States, but I've never seen it here), and the answer was this amazing substance called lecithin, about which, more later.

The other problem was to do with the jelly in my pork pies. Previously, I've made up small batches of the jelly by boiling pig or sheep feet in a savoury stock. The feet contain lots of gelatin, which sets the jelly at room temperature. But I decided it was too much hassle to make up fresh jelly for each batch of pies, so I made a bucketful and froze it in small containers. Somewhere between freezing and thawing, the jelly lost its set-ability, so I had a few customers whose pork pies dribbled on them when they bit into them. Not good. I did some online research, and found that yes, gelatin is broken down at a particular temperature, and loses the ability to set. This led me to explore the use of gelatin sheets combined with a super-intense stock, and the results are pretty marvellous. I also came across lots of Cooking 2.0 applications for gelatin, which I'll tell you about when I've had a chance to mess about with them.

Back to lecithin. This remarkable substance has the ability to make things like oil and water stick together when their natural inclination is to be apart. In other words, it's an emulsifier. It occurs naturally in eggs, which is why mayonaisse works. If you look at food labels, you'll find it in everything from chocolate to bread, and I've no doubt that brewers of horrible beer in the UK use it to make the foamy head last longer. In facts foams and 'airs' form a large part of the Cooking 2.0 repertoire: you can whizz any liquid (sweet, savoury, whatever) into foam, and if there's a bit of lecithin dissolved in it, the foam bubbles last for a very long time, rather than bursting after a few seconds.

I bought half a kilo of Soya Lecithin - it's also sold as a food supplement that is supposed to lower blood pressure and cholesterol, and have been having quite a lot of fun with it.

Next on my culinary adventure, I want to get hold of some Sodium Alginate, Calcium Chloride and Xanthan Gum. I tried the local pharmacy this morning and they've given me the address of a company in central Madrid who supply all kinds of exotic chemicals for all kinds of industries - I'm going there this evening, so I'll let you know how I get on. The first two of those chemicals, by the way, are used in 'sphericisation' - this is a method of encasing an intensely flavoured liquid into a neutral-tasting gel shell. When you bite into the shell, the taste explodes in your mouth. Depending on the size of your droplets, the spheres can resemble caviare or olives.

And finally, another technique I stumbled across: sous vide cooking (French for 'under vacuum'). I've tried many techniques for getting really tender meat and fish, none of them entirely successful, but this one looks promising. Basically what you do is you stick your seasoned meat or fish (or vegetables) into a plastic bag, suck the air out of it and then seal it. Then you place it in a container of water at a specific temperature (always much less than boiling) and wait for the specified number of hours. There are devices available that will maintain the water at the specified temperature more or less forever, but they are not cheap. However, I came across The Beer Cooler Hack, and I'm using it right now to cook a breast of duck. As far as vacuum-wrapping the meat goes, you can buy machines to do this, or you can buy your meat already packed this way (but then you can't add any seasoning), or you can improvise with a zip-lock freezer bag and a drinking straw. As it happens, I have a roll of polythene tubing and a heat-sealing machine that I use for packaging my pies, so I cut a length of tube, sealed one end, put the seasoned duck in, sealed the other end, cut a small slit to insert a straw and suck the air out, and then sealed over the slit. Fingers crossed!

And the final weapon in the Cooking 2.0 arsenal: liquid nitrogen for instantly freezing stuff. I think I'll be giving that one a miss!

UPDATE: I found the mystery ingredients shop: they were just pulling the shutters across - closing an hour early because their computer was down. But the guy took a look at my list and confirmed they had all the things on it (woohoo!).