shelf life for WVO
 

What is the expected shelf life for filtered WVO? Will it spoil, and if so are there any tips for prolonging its usability--other than keeping it water free and out of the sun?

I'm hoping to convince a local fish and chip restaurant to give me their WVO, and I'm expecting it to be quite alot--more than I can use possibly.

The only problem I had with storing wvo is that I started to see some alge growing in the bag filter I use for the initial straining. Unlike gasoline I think you can store wvo for ever esp. if you dosed it with a biocide to keep down alge growth. I have had dino-Diesel stored in my generator for years and it still starts up easily.

A note on collecting the wvo. Get a 12 volt rubber impeller pump ($34. from Harbor Freight calalog). When you get the oil just suck off the top layer. Don't put the hose to the bottom. Just keep it below the surface by a inch or so. Ask your local restrauants or hamberger joint for the 5 gal. clear plastic ''cubes' inwhich they get their fry oil. By using these cubes you can moniter the 'clearness' of the oil you are getting. As soon as you start seeing sludge or milky oil stop.

If you get your oil from a place that does not fry meat products you may not see this sludge. I think it is the meat fat that causes these clouds of light colored pollutants. These will clog up you filters and probably your fuel tank strainer. It happened to me in my Diesel truck.

Before you put your wvo into your car first decant it into these cubes and let it stand for a day or so. You will see the sludge settle to the bottom. You can then syphon off the clearer oil from the top. Pour the sludge into a seperate cube and return it to the restaurent grease tank or run it back through your filter process. Be sure that the inlet of the pump you use to take the oil out of your filtering tank is well off the bottom of the tank. This will help prevent sucking up more sludge.

When I use the 55 gals. in my primary filter tank I pump out the sludge and wash the tank. It is amazing the amt. of sludge that collects. Also be careful of water in the oil. This is what causes the alge growth.

Good luck.

All oil will eventually go rancid, IE, oxidize.

Saturated fats oxidize slower than unsaturated fats, so 'crisco'-like oils will go rancid much slower.

You want to keep the oil water-free, out of the light, and in a well sealed container with as little head-space as possible. Water, light, and air will all accellerate the oxidation process.

If your oil smells like linseed oil, its rancid, and shouldn't be used.

There are so many variables that it can be very hard to give any reasonable 'shelf life' numbers, but I'd say it can vary from a few months to a few years, depending on the oil, its water content, and how it is being stored.

peace,
sam

PS The same storage guidelines go for biodiesel too.

To maximise oil storage life you should:
- Filter the oil to remove contaminants
- Dry the oil, to reduce the microbial activity (usually at the oil/water interface)
- Fill the containers and seal, to minimise the amount of oxygen available to participate in oxidation of the oil.
- Store in a cool (preferrably COLD) place.
- Store in a DARK place.
- Exclude rodents and other hungry animals/insects.
I have stored >100 litres of WVO for 12 months with no issues when re-filtered and used as a fuel in my MB 300D. A small amount of the oil was removed in filtering, but no tests were done to determine why.

THE BEST, MOST STORABLE OILs are SOLID at storage temperatures. eg store at 30'C, use tallow or hydrogenated oils. at -30'C almost any oil is solid.

kits used?
 

I'm curious how you all modified your MBs? Did you use kits or fabricate your own setup? I'm shopping for a 300SD right now and my friends tell me to use the greasecar.com kit. Sage advice welcome!

Lord Diesel, I have responded to your question in another thread HERE

How does the fact that wvo may go rancid effect its use as a Diesel fuel? I certainly wouldn't use it to cook frys in but I can't believe that a Diesel engine knows the difference between fresh and rancid oil.

Rancidity can cause two things, one of which affects its use as a fuel. The first problem is that unsaturated fats can have random unpleasant molecules connect to the empty positions that would normally be filled by hydrogen atoms (on hydrogenated fats). These random molecules smell and taste bad. Yuck.

The other problem is that it can cause polymerization of the oil. Boiled linseed oil is in fact intentionally polymerized oil, which is why it is so good for wood, the polymers form a varnish which is protective for wood. However, that same polymer varnish that is so good for wood is terrible for your engine. In fact, polymerized oil and biodiesel has caused most of the unpleasant problems you may have heard associated with those fuels. Fortunately there are simple ways to avoid the problems (not removing Vitamin E from oils before processing, for instance), but when it happens, it is always bad.

If your WVO has gone rancid, it may be prone to polymerization, which is something you really want to avoid.

However, like mentioned, there are things you can do to keep it stable for quite a long time.

peace,
sam