Most people oil a board once, if at all, using whatever's nearest. Usually that's the olive oil, because it's already open and it's a kitchen, so it seems reasonable.
It isn't, and I'll come to why.
But first there's a thing worth untangling, because nearly every article on this gets it muddled. There are two separate questions here, and they have different answers.
The first is what goes on a new board, once, to seal it properly. That's the maker's job, and it happens before the board ever reaches you.
The second is what you put on it at home, every few weeks, for the next twenty years. That's your job, and it's a different product entirely.
Mixing the two up is where people go wrong.
What I finish boards with
Rubio Monocoat, mostly. Osmo TopOil on some pieces.
Rubio is a molecular bonding oil, which is a slightly grand way of saying it chemically bonds to the top layer of wood fibres rather than sitting on the surface as a film. One coat, that's the whole thing, there's no building up of layers. It's what I reach for on most boards.
Osmo TopOil is a hardwax oil, made for worktops and tables, so it's had a hard life tested into it already. It leaves a very thin protective layer and takes a bit more knocking about.
Both are certified for food contact once fully cured. That last word is doing a lot of work. Uncured, neither of these is something you want under a knife and next to your bread. Cure takes days, not hours, and on a board I leave it longer than the tin says because there's no reason to rush it.
This is why I don't recommend either of these as a DIY job on a board you already own. Not because they're bad, they're excellent, but because getting them right means surface prep, a dust-free space, an even wipe-on and wipe-off, and then the discipline to leave the thing completely alone for a fortnight. Most people don't have the space or the patience, and a half-cured board is worse than an unfinished one.
If you've bought a board from a maker, it's already done. Leave it be.
What you should use at home
Food-grade mineral oil.
It's a refined petroleum product, which sounds worse than it is. The food-grade version is the same stuff sold in pharmacies. It's inert, it has no smell, and it never goes rancid. It can't, because there's nothing in it to spoil.
It's also cheap. A bottle costs a few pounds and will last you years.
It doesn't cure or harden. It sits in the wood and slowly works its way back out, which is exactly what you want for maintenance. You're not re-finishing the board, you're topping up the moisture the wood has lost. Think of it as feeding rather than sealing.
Once a month for the first few months of a board's life, then whenever it starts looking pale and thirsty. You'll know. Wood tells you.
Beeswax butter, if you want it
A board butter is mineral oil with beeswax melted into it, roughly four parts oil to one part wax.
The wax sits nearer the surface and gives you a bit of water beading, so a spill sits on top for a second rather than going straight in. It also gives the board a soft sheen that oil alone doesn't.
It isn't essential. It's a nice half-step, and it makes a board feel finished in the hand. I use it on boards that live out on a worktop, less so on the ones that get hammered daily.
I make my own, because it takes ten minutes and a bowl over a pan of hot water. Melt the beeswax into the oil, pour it into a tin, let it set. That's the whole recipe, and there's no reason you couldn't do the same. I'm mulling over whether to sell it in a tin, which is probably a sign I should just get on and decide.
Olive oil, and the rest of the cupboard
Here's the bit that matters most, because it's the mistake nearly everyone makes.
Olive oil, sunflower oil, vegetable oil, and most of what's in your cupboard will go rancid. Not immediately, and not dramatically. It takes a few weeks, sometimes a couple of months. Then one day you pick the board up and it smells faintly of old chip fat, and that smell is inside the wood, not on it.
You can't wash it out. Sanding back is the only fix, and on a board you've had a while that's a proper job.
The chemistry is straightforward. These are unsaturated oils, they oxidise, and oxidised fat smells like oxidised fat. It's the same process that turns a forgotten bottle at the back of a cupboard.
There's a case for coconut oil, on the grounds that it's mostly saturated and doesn't spoil the same way. That's fair enough as far as it goes. But it costs more than mineral oil and does the job no better, so I've never seen the point.
The one to actually avoid
Boiled linseed oil.
It's sold everywhere, it's cheap, and it's a genuinely good wood finish. It also contains metallic driers, usually cobalt or manganese compounds, added to speed up curing. Those are not something you want near food.
Raw linseed oil has no driers, but it takes weeks to cure and can still go off. Walnut oil is a real drying oil and is food safe, though it's an obvious problem in a house with a nut allergy.
None of them are worth the bother when mineral oil sits on a shelf for a few quid.
How to actually do it
Nothing complicated.
1. Board clean and completely dry. Damp wood won't take oil.
2. Pour on more than feels sensible.
3. Spread it with a cloth or your hand, both faces and all four edges. Boards absorb unevenly if you only do the top, and an unevenly fed board is a board that warps.
4. Leave it. An hour minimum, overnight is better.
5. Wipe off whatever hasn't soaked in.
6. If you're using a butter, that goes on after. Thin coat, buffed off once it's had twenty minutes.
Do that once a month at first. After that, when the wood looks dry and light, it's asking.
That's the whole of it. The clever finish is my problem. The mineral oil is yours, and it's the easy half.
**Want the short version for your kitchen drawer?**
I've made a one-page care card, A6, the whole thing condensed to what you actually need to remember. It's free. Drop your email and I'll send it over, along with the occasional note from the workshop. No spam, and not often.
If I do end up putting the board butter in tins, the people on that list will hear first.
*If you're wondering whether a wooden board is even the right choice in the first place, I wrote about [wood versus plastic] a while back. And if you're after a board that'll take this kind of care and give you twenty years back, [mine are here](/collections/boards).*
0 comments