The early vs late addition of salt

[John M]

Hello Heston,

I've been reading the question and answer session with great interest, and have hugely enjoyed (and learnt from) your answers, so thank you very much! I even went so far as immediately to try your roast potato method (sorry to pre-empt the great egullet cook-off), and this leads me to a question about molecular gastronomy, and its different applications to different foods.

The method for roast potatoes was excellent in the most important ways, and produced a lovely crispy outside with a soft inside, and the late addition of herbs is a great idea, because they retain some colour and much more flavour.

My only problem was that the potato itself (inside its deliciously crispy, thyme and rosemary flecked coating) tasted a little bland. Of course, this could be because I didn't use good enough potatoes, although I did take care to buy the best I could find. I was just wondering if this could be anything to do with NOT salting the water much earlier in the cooking process. The salt added at the end did not seem to 'get to' the inside of the potato properly, did not lift its flavour in the same way as salt added earlier.

Could it be that the sound science behind NOT adding salt to green vegetables could be less successful when applied to potatoes (and, perhaps pasta, though I haven't tried this...). Could it be that adding salt to potatoes early in the cooking process achieves something (perhaps relating to the make-up of potatoes) that adding salt later cannot? I think Stenigarten talks about something like this more generally in his essay on salt, suggesting that early and late salt tastes different.

I'd be very interested to hear any thoughts you had on this issue...

Best wishes,

John M

[Heston Blumenthal]

Hello John,

Its' great that you tried the potaotes,. Indeed the lack of salt does show through at the end in terms of seasoning.

The problem is that salting the cooking of water can really affect the crust on the potatoes.

I have to be honest however and say that I have not tried salting the potatoes whilst they are roasting, this may not be anywhere near as detrimental and may produce a better-seasoned result.

How about injecting the potato with a saline solution, or even something else (sorry, I am going off ona tangent here!)

One thing that I tend to do is to cut the potatoes quite small; this way the lack of seasoning in the centre will not be so apparant. I also then use a mixture of fine salt and fleur de sel which works well.

Certainly a completely different set of factors apply when talking aboutthe use of salt in the cooking of other vegetables.

The only time that I would not use salt when cooking potatoes is when the potato is required to be served crisp (browned), otherwise salt would allways be added.

Salt in the cooking water of pasta is important altohugh having said that, we have been doing a bit of work on this recently and adding a really healthy (if you can use this word) dose of salt in the pasta dough, enough to make it taste too salty gives the dough more resistance and bite and in this case, it is not so important to salt the water.

This is because the sodium in the salt forms quite strong bonds (although not as much as calcium) and creates a tougher structure in the dough.

There is a huge on going argument as to the benefits of salt in meat cookery and wether or not it should be added at the beginning middle or end or at all three stages?

There is still no definate agreement. Even my friend Herve This, the french molecular gastronomist (he has a phD in this!)held a workshop on this very subject!