Up in smoke: what makes smoked fish so irresistible?
This Christmas saw rises across the board in sales of smoked salmon from all the major supermarkets, despite our tighter budgets – in readymade canapés from Waitrose and big packs at Morrisons. Why are we so reluctant to give up this delicacy over all others?
Barney Peterkin works at the Valley Smokehouse in the Chew valley outside Bristol. They supply Raymond Blanc’s restaurant, The Manoir aux Quat’Saisons as well as many other restaurants. He talked me through the process at their smokehouse.
"Smoking's not done for preserving anymore, it’s done for taste. Modern refrigeration means you’re not hanging the product up for the winter – people now would find smoked fish from years ago very unpalatable, a lot smokier and a lot saltier. It was rough peasant food, and now it's a luxury food."
Arbroath smokies are so carefully produced by Scottish smokehouses they have been given Protected Geographical Indication (PGI) status by the European Commission.
In medieval times, whole, ungutted Yarmouth red herring were left in the salt for days before being smoked for weeks. The end product could last up to a year, but was so strong-smelling that it could be used to cover up a scent trail – hence the phrase.
So what happens in modern smokehouses? “First, we do a dry cure on all our salmon. A lot of industrially processed salmon is injected with a wet brine, increasing the liquid content in the fish, while we’re trying to get water out. “
A wet brine is popular with big smokehouses as it produces predictable results. As Saul Zabar, co-owner of America’s premier deli and smoked fish emporium, said, “Dry curing is like a virtuoso violinist, sometimes he’s great, sometimes not.” Even Keith Erlandson’s seminal work “Home-smoking and Curing” recommends an 80% salt solution for best results. It’s a very personal decision.
Barney continues, “So our curing process takes a day, then we put the fish in the smoker until we think it’s ready – generally about 12-14 hours. We adjust the distance of the smoke boxes to apply more or less heat or smoke- it’s all judged by eye and experience. Everything we do here is with green oak chippings, we find that we get the best and most consistent results. Not all fish takes well to different woods. “
The type of wood used to generate the smoke has a big effect on the flavour. Hard woods like oak, apple and cherry contain more lignin- the cells that give wood its strength. The bulk of any plant structure is cellulose which gives the smoke a floral, buttery, grassy taste. The lignin releases vanilla and clove flavour compounds. (These same compounds are added to wine by scorching the casks in which the wines are aged.)
“We rest it for four days after the smoke – if we used it straight out of the smoker, it wouldn’t slice brilliantly and it wouldn’t taste as good. It takes about a week to produce each fish. The cheap stuff will go from fresh to packet in maybe 24 hours. And that bright yellow haddock you get in the supermarket may not even have gone into the smoker, it’s often been sprayed with liquid smoke.”
Liquid smoke is also sold in bottles for domestic use, and is created by condensing smoke vapour and dissolving the flavour compounds in water. I couldn’t bring myself to ask Barney if he thought it was cheating – I felt I knew what he might say.
But in theory, Barney’s up for applying smoke to almost anything. “We do smoked butter and cream and oils for the catering trade – there’s a lot more innovation in that market. They want inert carriers of the smoke flavour. Because we’re flexible in what we can do, chefs will come to us and ask to try different things. One time, we had a bloke up here with a painting – he wanted it aged somewhat – I’m not sure it was a strictly legal situation. We politely said, no thanks.”
If you’re looking for a weekend project, and the snow doesn’t pile up on your doorstep, you could have a go at doing some home-smoking. There are great resources out there, and you can build your own Heath Robinson style smoker with some ingenuity and research. (I’ve got my eye on adapting an old electric oven.) But even with an ordinary kettle barbecue, you can start to experiment. I asked Barney for his tips.
“If you’re looking to do it at home and get a good result – cook it as low a temperature as you can. You don’t want to get the heat up with lots of smoke – it will be too bitter, too smoky and it will taste burned. The smoke should smell lovely and sweet, and you should want to breathe it in. If you have a barbecue with a lid, you can achieve some really good results. Build your charcoal up on one side, then on the other side, use a tin can with some sawdust and get it gently smouldering away. Don’t chuck your food, the sawdust and charcoal all in at once – if the temperature’s wrong, you can always start again before you put the food in. Also, be aware that the flavour will build over days. Leave it for a day or a couple of days to mellow.”
Would you have a go at home smoking? Are there any tips you’d pass on?
Radio 4's new food series, The Kitchen Cabinet discusses whether home smoking is worthwhile.