Finishing Wood pieces for use with Food

[Spoon Man]

I don't have a question so much as I do information that I have gained through reading over time on what is the best finish for wooden bowls & utensils.

It concerns me that mineral oil is recommended for use with pieces to be used with food as mineral oil is a by product of petroleum. Not exactly a healthy idea.

I have also read others recommending olive or vegetable oils. These aren't ideal either as these oils can turn rancid over time which could result in potential food poisoning.

What I have found is that walnut oil is the way to go. It is an oil that doesn't turn rancid and is healthy to consume.....it also smells amazing. I often mix this oil with bees wax into a pot and melt together then apply to my spoons. I hope this helps anyone who makes pieces for use with food. I would also be interested in anyone elses suggestions.

[rsser]

Thanks for the post Spoonster.

AFAIK Olive Oil is the only common veg oil that can go rancid. Any nut oil is fine in my experience (added: sunflower, safflower etc. Lot cheaper than Walnut oil.)

I know of one pro turner who dropped all his production kitchen items into a drum of cheap nut oil overnight and then drained them and left them to dry. I think if you let them sit for a while the oil hardens.

[Alastair]

Hi Guys

I work in the fats and oils industry, so can give some definitive info.

First, while I agree with the inconsistency regarding mineral oil and food, the advantage is that it is largely inert. Does not go rancid or sticky. Also, was used 'medicinally' for years, (liquid paraffin/ Vaseline).

Regarding the vegetable oils, firstly, all go rancid; it is the nature of the beast. Incidentally, the products of rancidity are not toxic in any way, and are similar to the end of the digestive process for edible oils. What differs is that they develop varying degrees of objectionable odour and taste, depending on species. Palm oil develops a sweetish note; peanut oil, (and probably walnut) get 'nuttier'. Sunflower and safflower (to me) develop an "old bags" taint which I find objectionable. Bean oil gets 'beanier', while canola gets a 'fishy' offtaste. Olive , like linseed, gets an 'old paint' note.

What also differs is the rate at which this happens. As most of the nut or salad oils are refined, they begin bland, but as all the natural antioxidants have been removed in the processing, they deteriorate quickly. Extra Virgin olive oil is unrefined, and has high levels of antoxidants. While it is strong flavored from the outset, it takes far longer to become rancid than the others.

Remaining difference is the performance on the piece. Linseed is well known as a finish in its own right, as well as a component in paints and varnishes. This is because it is what is known as a drying oil, as is tung. This is because they polymerise into a cross-linked form during oxidation. What is less known, is that bean oil, peanut, (and I suspect walnut) sunflower and safflower can be used in similar applications, only slightly less effectively. One only has to see the gummy 'varnish" which collects on range hoods where a lot of frying is done. Olive oil is the least of the polymerising oils.

From a technical point of view, I would recommend the following:

Where the piece is to be "finished" in a more permanent sense, like cheese boards, chopping blocks, fruit bowls, use one of the vegetable "drying" oils, like sunflower as above. Allow to soak into timber, and allow enough time for it to polymerise and dry, which will eventually give a 'permanent ' finish, like linseed oil. Bear in mind that this can take a while.

Where the finish needs to be renewed, like a salad bowl which is frequently washed, probably the best would be to wipe with olive oil after washing and drying, provided the taste is not found objectionable. The other oils will tend to build up to a sticky residue if used this way.

Hope this helps

[rsser]

... best post I've read on the topic.

While having treated my big plane tree bowl with sunflower oil from 'new' (and it soaked up a lot of it), it now just gets washed in the sink like everything else.

I guess if it looked a little prettier it would get more attention ;-}

[Ashore]

There have a couple of other threads about suitable finishes for food bowls boards etc and a lot op people like myself use organoil hard burnishing oil, when applied with a little heat works a treat and has a pleasant citrus smell

[RufflyRustic]

Er, hang on a minute, what about the people who are extremely allergic to nuts, any nuts, including the nut oils??

[Alastair]

Hi RR

An interesting question. Firstly, your comment, "....even the nut oils........"

As the science would have it, the allergy is to the residual protein, not the oil itself, so for highly refined oils, there should not be a problem. I cannot obviously guarantee that this is always the case, especially regarding the oft quoted sensitivity to peanut. In general, where this occurs, is where "nut" oils like peanut or sesame are used in cooking, esp asian. Here these are often the unrefined "cold pressed" oils, and are used for their flavour contribution. In these cases there is obviously a higher likelihood of the presence of residual protein. Probably best to stay away from these.

Food legislation here does not require declaration of any of the seed oils, (sunflower, safflower, canola, maize, linseed) or fruit oils (palm, palm kernel, coconut, olive) Declaration is required for Soy, Peanut, sesame, and "nut oils" like walnut etc.

[rsser]

... or go for Parrifin?

Used to be able to get it from a chemist.

[RufflyRustic]

Thanks Alastair

[Harry72]

Alastair you sound like a industrial chemist?

[Spoon Man]

Thanks Alastair for the excellent explanation of the oils.....this information is very valuable.

[ubeaut]

Could be completely wrong here but I was under the impression that mineral (paraffin) oil was the only oil classified as food safe for use on wooden bowls etc by the US Food and Drug Administration.

Like I said I could be wrong.

Personally I still believe the best finish to be no finish for wooden bowls and utensils that are going to be used. We have used wooden utensils since I can remember, none were ever finished or oiled and none have ever made any of our family sick. Proper hygiene as with all cooking utensils is essential but other then a wash in hot soapy water they need nothing else and after a while will take on a life, finish and patina of their own.

You can buy wooden spoons in any kitchen shop, department store, $2 shop etc and you will never find them finished. Always raw timber. These are made by people who know the business and know what works. Otherwise they wouldn't still be in business as law suits would have shut them down years ago.

[Alastair]

Hi Neil

You are obviously right regarding unfinished timber.

There has been a lot of discussion that I have read, stemming from the regulation in the food industry outlawing the use of wooded cutting boards. One of the articles is here:

http://faculty.vetmed.ucdavis.edu/fa...ttingboard.htm

I suspect that it has less to do with safety, but more with aesthetics, with some people not enjoying the 'life, finish and patina ' as much as you do.

regards

[ubeaut]

Think you will find that wood is now back in favor and the plastics are no longer the preferred cutting boards etc. Takes some people a long time to learn that new modern materials and methods aren't always the best.

Personally I'd rather the bacteria be drawn away from the work surface and drawn into the timber to die a slow death, rather than have it sit on the surface of a plastic board and multiply at an alarming rate.

I have always been of the opinion that almost any surface coating on wood, could have much the same affect of allowing bacteria to multiply. hence my preference for raw timber. With maybe a coat of paraffin oil to show the timber off for sale. Paraffin because it's non toxic, completely inert, non drying and no matter what you do to it, it won't go rancid.

Some 30 years ago I used to sell my woodwork (very successfully I might add) at a pretty exclusive craft market and I have seen and smelt some terribly nasty stuff on bread boards and chopping boards after they were left in plastic bags in the sun or boot of a car for many weeks prior to their sale. Mine on the other hand were finished with a coat of paraffin, wiped down to remove any excess then sealed tightly in plastic bags and never a one was anything less then perfect when released from the bag, even after many months.

[soundman]

I recon you would have to go a long way past parafin or shealc for being food safe. Bees and parafin wax too I supose but they are a different story.
All have a long history in pharmacy and the food industry.

I have seen parafin oil on the shelf in Bunnies.

the other thing about parafin oil is that it isnt going to set up as such so it isn't going to "seal" the wood. so I would expect it would be closer to a raw timber result from the point of view of the wood doing its trick with the bacteria.

tests needed.

But it will give a "finished" appearance that customers expect and will help the product sell.

cheers