What Are The Sticks In Oil Called?

“Sticks” in oil refers to small fibrous particulates that can form in oils during cooking or storage. They are also sometimes called “foots” or “bottoms.” Sticks are composed of compounds like triglycerides and fatty acids that harden into solid pieces when exposed to air, light, and heat over time. Their appearance ranges from translucent specks to opaque brown threads that resemble wood shavings or bark chips, hence the name “sticks.” While visually unappealing, sticks are not inherently dangerous and can often be filtered out.

The formation of these particulates is a natural process due to the chemical composition of oils. With proper care and handling, sticks can be minimized. Understanding what causes them and how to manage their occurrence can help cooks use oils to their fullest potential.

What Are Sticks in Oil?

Sticks in oil, also known as crystals or reeds, are solid formations that develop in oils as they cool and thicken. They consist of saturated fats that crystallize and solidify as the temperature drops. This causes the fats to separate from the liquid oil and clump together in stick-like shapes. Reed diffusers are a common application that utilizes sticks in fragrance oils to disperse aromas. The reeds absorb the oil and allow the scent to gradually permeate the air. Sticks can also form in cooking oils that have been chilled or refrigerated after use. As oils containing higher amounts of saturated fats cool below room temperature, the saturated fats will begin crystallizing into sticks.

According to Lifestyle Packaging, reed diffuser sticks are typically made of rattan, bamboo, or other natural materials that effectively wick the fragrance oil (“How Do Reed Diffusers Work?”, 2022). The oil travels up the hollow reeds through capillary action, allowing the scent to diffuse into the surroundings. The more reed sticks in a diffuser, the stronger the fragrance. While reed diffusers rely on sticks in fragrance oils to disperse aromas, the formation of sticks in cooking oils is often undesirable and a sign that the oil has been stored improperly.

Chemical Composition

Sticks in oil are made up of saturated and unsaturated fats that crystallize and form a solid structure (Source: https://www.fishersci.com/shop/products/sodium-sticks-coated-film-protective-hydrocarbon-oil-99-thermo-scientific/AAL1328524). The chemical composition depends on the type of oil, but generally sticks consist of triglycerides which are molecules composed of three fatty acids bound to a glycerol backbone. The fatty acids can be saturated, monounsaturated, or polyunsaturated. Saturated fats like palmitic and stearic acid tend to be solid at room temperature while unsaturated fats like oleic acid are liquid. The ratio of saturated to unsaturated fats determines the melting point and hardness of the sticks.

Sticks form when the oil is cooled and the saturated fatty acids crystallize first, aggregating into a solid network while the unsaturated fats remain liquid. Factors like the degree of saturation, types of fatty acids present, and speed of cooling impact the crystal formation process. The end result is a matrix of crystallized saturated fats interspersed with liquid oil.

Formation Process

Oil sticks form when saturated and unsaturated fats naturally present in oils begin to crystallize and solidify as the temperature drops. This process is known as the oils’ “cloud point” or solidification point. As oils like soybean and canola cool down from heated processing temperatures, the fats with higher melting points start to come out of solution and aggregate into small crystalline clusters along the sides of storage vessels and pipelines. Over time, these clusters accumulate into sludgy deposits that stick to equipment surfaces. Prolonged cooling turns these deposits into harder waxy solids that appear as sticks or elongated pieces in the oil.

The shape and consistency of these oil sticks depends on the types of fats present and how quickly the oil cooled. Oils higher in saturated fats like coconut and palm form harder sticks. Slow cooling also promotes more complete fat crystallization into larger networks, forming more solid sticks rather than soft sludge. Proper temperature control and managing oil composition are important to minimize stick formation during processing and storage. But some stick formation is inevitable in oils containing saturated fats.

Sources:

https://www.sciencedirect.com/topics/food-science/fat-crystallization

https://www.mdpi.com/2304-8158/2/2/165/htm

Effects on Food

The formation of sticks, or food particles, during frying can significantly impact the texture and mouthfeel of foods (Snack Food & Wholesale Bakery, 2015). As oils are heated and reused, more food bits and carbohydrates accumulate in the oil, leading to increased stick formation and adhesion during frying. This can result in foods with a unpleasantly hard or crunchy exterior according to research discussed on Reddit (Reddit, 2020).

The reasons behind the textural changes are complex, but generally attributed to chemical reactions between oil components and food starches and proteins. As reported by Healthline, this can create a tough external barrier and crust (Healthline, 2022). Oil uptake itself also impacts texture by displacing internal moisture in foods like potato sticks according to a study in the National Center for Biotechnology Information (Yang, 2020).

Overall, while small amounts of sticks may be inevitable during frying, excessive buildup can create an unappetizing mouthfeel and diminished food quality. Careful monitoring of oil conditions is important.

Managing Sticks

There are a few strategies that can help prevent or remove sticks that form in cooking oils:

Filtration – Straining oils through a fine mesh strainer or cheesecloth can help remove many of the particles that cause sticks. This can be done after each use while the oil is still warm. Mesh splatter screens can also be used while frying to catch stray particles (source).

Managing Temperature – Heating oil to the proper frying temperature can help avoid sticks. Generally 350-375°F for pan frying is ideal. Overheating oil can cause more rapid oxidation and stick formation (source).

Replacing Oil – Over time, oils will oxidize and sticks will accumulate. Replacing cooking oils every 4-6 uses can help minimize buildup of sediment and particulates (source).

Salt – Adding a pinch of salt to hot oil can help break down sticks and prevent splattering by raising the smoke point. However, this should be done minimally to avoid over-seasoning foods (source).

Types of Oils

The composition of sticks that form in oil depends largely on the type of oil used. Some common types of oils that can develop sticks include:

Olive Oil – Sticks in olive oil are composed primarily of saturated fatty acids like palmitic acid and stearic acid. These fatty acids solidify at cooler temperatures causing the sticks. [1]

Coconut Oil – The sticks that form in coconut oil also contain high amounts of saturated fats. However, coconut oil is very high in lauric acid which has a lower melting point than palmitic and stearic acid. This makes the sticks softer. [2]

Sunflower Oil – Sunflower oil is high in polyunsaturated linoleic acid so sticks are unlikely to form except at very cold temperatures. Sticks would be composed of oleic and stearic acids. [3]

The more saturated the oil, the more solid the sticks will be at room temperature. Oils higher in polyunsaturated fats like sunflower oil are less likely to form visible sticks.

Culinary Uses

Sticks are often used in recipes to add subtle flavor and texture. When cooking meat or vegetables in oil, the meat proteins and plant fibers can cause strands or small bits to break off the main ingredient and coagulate in the oil. These strands are commonly referred to as “sticks.”

The sticks impart extra browning, caramelization, and aromatic qualities as they cook in the oil. This can enhance the overall flavor of stir-fries, pan-fried dishes, deep-fried foods, and more. The textural contrast of crispy sticks against tender meat or soft vegetables is also desirable in many cuisines around the world.

Some chefs intentionally add sticks to hot oil as a finishing touch. For example, finely chopped sticks may be sprinkled over fried rice or noodle dishes right before serving. The hot oil causes the sticks to take on a toasted, nutty flavor. When used properly, sticks can provide intrigue and complexity without overpowering the other ingredients.

Sticks are especially prevalent in Chinese stir-frying techniques. The high heat causes small bits of meat and vegetables to separate and caramelize in the oil, creating signature “wok hay” flavor. Skilled chefs know how to control the stick formation for optimal taste and texture.

Health Considerations

When it comes to the nutritional profile and health effects of consuming sticks, there are a few key things to keep in mind. According to research by Poison.org [1], sticks are made from natural plant fibers like rattan, bamboo, and paulownia wood. As such, they contain very little nutritional value and are not intended for human consumption. Eating sticks could potentially cause choking or internal injury due to their rigid structure and sharp edges. Additionally, some sticks may be treated with chemicals during processing that could have toxic effects if ingested.

A few small studies have looked at the health effects of consuming flavored sticks like cinnamon or fruit-infused varieties. While these additives may provide trace amounts of nutrients, the overall consensus is that intentionally eating sticks provides no health benefits and may pose safety risks. For example, a case study in the Journal of Pediatrics found that a child who ingested part of a scented stick experienced vomiting, diarrhea, and chemical burns in the esophagus [2].

The takeaway is that sticks have no nutritional value and should not be eaten under normal circumstances. While a small taste out of curiosity may not cause harm in healthy adults, swallowing pieces of stick or ingesting scented varieties could potentially lead to choking hazards or toxic side effects. For children and pets especially, sticks should be kept safely out of reach and not treated as edible items.

Conclusion

Sticks in oil, also known as reeds or rattan sticks, play an important role in products like reed diffusers. While simple in appearance, these sticks have a specific chemical composition and capillary action that allows them to gradually diffuse fragrance oils into the air. When used properly in items like diffusers, sticks can provide continuous and customizable scents for homes or businesses. Overall, sticks are an ingenious and natural method for dispersing fragrances. With proper care and replacement, they can provide enduring ambiance and aromatic experiences.

In summary, sticks in oil work through capillary action to diffuse fragrance in a slow, consistent manner. Their porous structure absorbs oils through tiny channels and emits the scent into the surroundings over time. With an understanding of their composition and mechanics, sticks can be used effectively in reed diffusers, aromatherapy, and more. While providing aroma, sticks also serve as an attractive and eco-friendly alternative to sprays, candles, and other fragrance methods. When saturated properly with quality oils, these simple sticks have the power to transform environments through long-lasting, subtle scents.