A Barcelona food blog
Decifering Catalan, science, hangovers and young children. Not four things I’d usually choose to drag myself out of bed for on a Sunday morning but this was a chance to see some of the processes and food manipulation from the ‘Materia Condensada’ exhibition in action. With the eagerness of a youth I sat down alongside the kids and some very earnest parents and tried to tune into chemistry in a foreign tongue.
We started with the sodium benzoate and PCT (phenylthiocarbamide) paper test from the main exhibition. After the foul taste it left in my mouth last time I opted out of this and instead chose to revel in amusement at some of the strange faces and reactions from the rest of the audience.
The first demonstration was regarding emulsions. Harking back to school science we filled test tubes with a 50/50 mixture of oil and water which obviously didn’t mix, although the kids gave it a good effort of shaking to try. We then added the xantana (xanthan gum) which brought the two ingredients together and demonstrated it’s use as an emulsifier and thickener, a process that was explained further with some lego bricks. A later demonstration of jellies was accompanied by another model.
This kind of science I like, toys and practical demonstrations rather than equations.
The bottle of thickened cava passed around sparked the adults interest for a few minutes whilst the splattered tables were wiped for the next experiment.
In emulsions such as ailoli or mayonnaise, the garlic or egg proteins and some agitation act in the same way as the xanthan gum and forge the ingredients together. This was demonstrated by blending milk (milk proteins) with olive oil, creating a creamy, mayonnaise consistency. It was passed round for tasting, not offensive but imagine mayo without the eggs or the acid of the lemon. Euw.
Next it was the creation of a jelly. Sheets of animal based gelatine fascinated the young ones with their texture of plastic and the seaweed source of agar agar was shown in its natural and processed powdered form. The keen, possible chefs of the future made and heated a mixture of pineapple & grape juice with the powdered agar agar (100ml juice to 2g agar agar in this instance but a softer sonsistency can be made with 1g of agar agar, it doesn’t work well with acidic liquids so don’t try this with orange juice.) This was then poured into plastic cups to set. Now all they had to do was wait.
The process of spherification I have found the most interesting and novel for food presentation. Each table was given a shot glass of pea purée which had been mixed with alginat, another seaweed derivative, at a concentration of 6.5g alginat per litre of liquid ingredient. Alongside this was a bowl of water containing calcic, a form of calcium, this time at a preparation of 5g calcic to 1ltr of water.
The alginat, calcic and use of agar agar have all been developed or their use expanded by the Adrià brothers at their Barcelona workshop and are now sold as a line of products named ‘Texturas’. For anyone living in Barcelona who fancies attempting any of this, they can be purchased from a small shop called ‘Solé Graells’ located on a tiny back street just behind Plaça d’Espanya, if you are further afield they can be bought online, there is a list of distributors on the ‘Texturas’ website.
So how does the spherification work? Once the two solutions have been prepared, the rest is quiet simple. A syringe is filled with the pea purée and then droplets are dripped into the calcic and water solution. On contact with each other they react and the liquid purée becomes a solid. This requires a steady hand and even droplets, the children made some excellent attempts as well as some rather heavy handed squirts.
The great thing about this is that the alginat and calcic do not alter the flavour of the purée, hence the capsule that bursts and spreads around your mouth tastes of purely pea.
If the liquid you want to solidify has a high calcium content already, such as yogurt at this workshop, then the process is inverted. The calcic is added to the yogurt and the ‘bath’ is mixed with the alginat, the concentrations for each remain the same as previously. Here are the results of the yogurt ‘ravioli’:
Once the ‘spherification’ has happened, the droplets are strained from the liquid and will hold their shape indefinitely so can be stored for as long as you would normally store the base ingredient, meaning that this could easily be prepared beforehand and kept in the fridge for a dinner or a meal to impress someone special.
To end the session the final demonstration exampled changes in colour depending on the PH of different liquids.The glass on the left contains lemon juice with an acidic PH of around 2.5, in the centre a glass of water with a neutral PH of 7 and on the right an egg yolk with an alkaline PH of 8.9. A few droplets of water from boiled red cabbage were then added to each glass, the deep purple of the cabbage water changed depending on which solution it was added to, the colour with the egg yolk changing again when the alkalinity was neutralised with a drop of the lemon juice.
Thanks must be given to the Fundació Alícia for putting on this exhibition. The foundation, near Manresa about an hour and a half out of Barcelona, aims to continue culinary and scientific research and investigations into health and dietary habits. After the two enjoyable mornings I spent at Arts Santa Monica I eagerly look forward to taking up one of their workshops and guided tours.
There are two further ‘Materia Condensada’ workshops on Sundays 17th and 24th October and the main exhibition runs until 5th December 2010
‘Materia Condensada’, Arts Santa Monica, Rambla 7 (Drassanes)