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Orifice Reducers – FAQs

What is an orifice reducer?

If you are new to essential oils, you probably have never heard of an orifice reducer before. The orifice reducer is the clear/white thing inserted at the opening of an oil bottle. Basically, it makes the bottle opening (or “orifice”) smaller and reduces the flow of oil so only a drop comes out at a time.

Why do some orifice reducers work better than others?

Not all orifice reducers are the same, and some control the flow of oil better than others. The factors that usually determine this are the size of the opening in the orifice reducer, the placement of the flow stem (some are in the center; others are on the side), and the viscosity of the essential oil contained within the bottle. One other factor that is fairly easy to control is positioning the air hole according to the oil’s viscosity. How you do this depends on the type of orifice reducer you have.

Side Drip Orifice Reducers with a Center Stem
If you have an orifice reducer with a center stem (also called a “side drip orifice reducer”), the stem is the air hole, and the tiny hole between the 2 circles is the oil hole (hence the name “side drip”). This type of orifice reducer is common on essential oil vials from essential oil companies. To control the flow of oil with these orifice reducers, just find the tiny hole between the 2 circles; then position it down for thicker oils to help a drop come out, and position it up for thinner oils to slow down the number of drops. Positioning the oil hole at the bottom allows thick oils to flow more easily, since the hole is under the oil level, and allows air to flow into the bottle better because the stem is above the oil level. Both of these factors help the orifice reducer release a drop of the thick oil. When you position the oil hole at the top for thin oils, the opposite occurs, and it slows down the oil flow, preventing multiple drops from being released at the same time.

Center Drip Orifice Reducers with Side Stem
If you have an orifice reducer with the stem on the side, like the orifice reducers we carry, the oil comes from the center hole, and the air hole is found between the 2 circles where the stem is located. This type of orifice reducer is called a “center drip” orifice reducer. To control the flow of oil with these orifice reducers, just find the tiny hole between the 2 circles; then position it up for thicker oils to help a drop come out, and position it down for thinner oils to slow down the number of drops. Positioning the air flow stem at the top for thick oils allows the air to flow more freely, which releases pressure inside the bottle, allowing the thick oil to drip. When the air flow stem is positioned down (or at the bottom), the air can’t flow as freely, so the oil flow is slowed down. This helps control the flow of thin oils so only one drop is released at a time.

Why are orifice reducers important?

Because an orifice reducer is used to reduce the flow of oil so only a drop comes out at a time, we are able to better control the amount of oil we use. Without an orifice reducer, it would be hard to get a single drop of oil out alone.

I sometimes have a hard time getting oil out of my sample vials. How can I make this easier?

Most orifice reducers have a small hole that allows for air flow, but some of the small orifice reducers (like those found on sample bottles) don’t have an air flow hole. To get a drop of oil, simply tap the bottom of the vial a couple times. Note: The hole is a little small to get a full drop of oil, so it’s pretty safe to assume one tap is about equal to a 1/4–1/2 drop.

How do you insert an orifice reducer?

For regular size essential oil bottles, the orifice reducer and cap come together (sometimes called a Euro cap). The orifice reducer fits inside the cap and will pop into the bottle as the cap is screwed on.

For sample vials, an orifice reducer may need to be pushed in with your thumb, at least a little, before screwing the cap on and finishing the job. If you are putting together a lot of sample bottles, the O Presto tool may come in handy and save your hand a little pain as well as save some time. The O Presto has a slot for the 1/4 dram bottle size and the 5/8 dram bottle size. Simply place the bottle in the correct slot, place an orifice reducer on top, and push the wooden bar down to easily insert the orifice reducer.

How do you remove an orifice reducer from the bottle?

For regular size essential oil bottles, you can often easily remove the orifice reducer by placing the cap angled on the bottle, so the bottom catches the orifice reducer as you push the cap off to the side. Another way is to pry your fingernails underneath and gently pop the orifice reducer off.

For regular bottles and sample vials, the easiest way to remove the orifice reducer is with the aid of an Oil Key for Orifice Reducers. This handy tool has different slots for various types of orifice reducers, including orifice reducers on regular oil bottles, sample bottles, and roll-on bottles. The Oil Key can also help you put the orifice reducer back on when you are finished. You can attach this tool to your key ring or to the zipper on your oil bag so it is handy when you need it!


Because the tiny orifice reducers on sample vials tend to be more difficult to remove and can be ruined in the process, you can get extra orifice reducers here. If you are wanting to refill the sample vial with the same oil, it is much easier to leave the orifice reducer on and just use a small pipette to insert oil through the little hole.

Where do I purchase extra orifice reducers?

If you are cleaning and reusing your essential oil bottles or need extra orifice reducers for sample vials, you can purchase them at a low cost at
Orifice reducers and caps for 5 ml, 10 ml, 15 ml, and 30 ml essential oil bottles
Orifice reducers for 1/4 dram, 5/8 dram, and 1 dram sample vials

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