Yes, but only if the cup is made of borosilicate glass or tempered soda-lime glass designed for high heat. Standard soda-lime glass measuring cups—like many dollar-store or unbranded cups—can shatter when exposed to hot oil above 350°F. Even with heat-safe cups, you must avoid thermal shock by heating the cup gradually and never adding oil to a cold cup.

Quick Answer

Glass measuring cups can be safe for hot oil if they are heat-resistant and used correctly, but common mistakes like preheating on a burner or pouring cold oil into a hot cup cause breakage.

  • Shatter Risk: Standard soda-lime glass (e.g., Pyrex in the US) can withstand up to 425°F but fails under sudden temperature changes of more than 100°F.
  • Borosilicate Advantage: Borosilicate glass (e.g., old Pyrex, Anchor Hocking Vision) resists thermal shock up to 500°F and is safer for hot oil.
  • Thermal Shock: Pouring hot oil into a cold glass cup creates stress that can cause immediate cracking or delayed failure.
  • Microwave vs. Oven: Most glass measuring cups are microwave-safe but not oven-safe; never use them on a stovetop or under a broiler.
  • Label Check: Look for ‘borosilicate’ or ‘oven-safe’ on the bottom; if it just says ‘microwave-safe,’ assume it’s not for hot oil above 300°F.

What Kind of Glass Can Handle Hot Oil?

Two common types of glass are used for measuring cups: soda-lime glass and borosilicate glass. Soda-lime glass, which is what most modern Pyrex measuring cups are made of, has a maximum service temperature around 425°F but is prone to thermal shock. Borosilicate glass, found in brands like Anchor Hocking’s Vision line or older Pyrex (pre-1998), can withstand temperatures up to 500°F and sudden temperature changes of up to 350°F. For hot oil, which often reaches 350°F to 400°F for frying, borosilicate is the safer choice.

If you’re unsure about your cup’s material, check the bottom stamp. ‘Borosilicate’ or ‘oven-safe’ indicates it’s designed for high heat. ‘Microwave-safe’ alone means the cup may not handle direct heat from hot liquids. Some high-end brands like OXO Good Grips use tempered soda-lime glass that is tested for hot liquids, but still avoid extreme temperature swings.

Safe Temperature Limits for Common Brands

  • Pyrex (modern, US-made): Soda-lime glass, rated to 425°F. Safe for hot oil if preheated gently, but don’t place on a cold surface.
  • Anchor Hocking: Soda-lime glass, similar limits. Their ‘Fire-King’ line (older) is borosilicate.
  • Boroclar / Bomei: Borosilicate, often labeled as ‘heat-resistant glass.’ Rated to 500°F.
  • OXO Good Grips: Tempered soda-lime, tested for hot liquids, but not specifically rated for stovetop use.

Always check the manufacturer’s instructions. Many cups list a maximum temperature on the packaging or bottom. For deep frying, keep oil below 400°F to stay within safe limits for most glass cups.

How to Safely Use a Glass Measuring Cup with Hot Oil

  1. Preheat the cup: Rinse the cup with hot tap water (around 120°F) before pouring in hot oil. This reduces temperature shock.
  2. Heat oil gradually: If you’re measuring oil for a recipe, heat it in a pot, then pour it into the preheated cup. Avoid pouring oil that is over 400°F into any glass cup.
  3. Use a heat-safe surface: Set the cup on a dry wooden cutting board or a folded kitchen towel. Never place a hot glass cup on a cold countertop or metal sink.
  4. Never microwave oil: Oil can overheat quickly in a microwave and cause the glass to break. Always heat oil on the stovetop.
  5. Let it cool slowly: After use, let the cup cool on a trivet. Don’t run cold water over it or put it in the fridge while hot.

When to Avoid Glass Altogether

If you’re working with oil temperatures above 400°F—for example, when deep-frying at 375°F or searing at higher temps—it’s better to use a metal or silicone measuring cup. Glass cups also become very hot to the touch and lack handles that stay cool, increasing the risk of burns. For tasks like pouring hot oil into a jar for storage, use a stainless steel funnel and a heat-safe container.

Another risk: glass measuring cups have a spout and handle, but the handle is attached to the body. If the cup cracks, the handle may break off, causing a spill. For high-volume oil (more than 2 cups), opt for a metal liquid measure or a heavy-bottomed pot instead.

What to Do If Your Glass Cup Breaks

If a glass measuring cup shatters while holding hot oil, turn off the heat source immediately and don’t move the cup. Let the oil cool completely, then carefully dispose of the glass and oil in a metal container. Do not pour oil down the drain—it can clog pipes. Instead, let it solidify or mix with absorbent material like cat litter before throwing in the trash.

Inspect the cup for any chips or cracks before each use. Even a tiny nick can weaken the glass and cause failure under heat. Replace any cup that shows scratches from metal utensils or has a cloudy appearance, which indicates micro-cracks.

Pro Tips

  • Warm the glass cup with hot tap water before pouring in hot oil to reduce thermal shock.
  • Use a candy thermometer to keep oil below 400°F when using a glass measuring cup.
  • Place the cup on a folded towel or wooden board, not directly on a cold countertop or metal surface.
  • If you have an older Pyrex (pre-1998), it’s borosilicate—more heat-safe than modern Pyrex.

Common Mistakes to Avoid

  • Pouring hot oil into a cold glass cup straight from the fridge or cabinet.
  • Heating a glass measuring cup on the stovetop to preheat it—this can cause uneven expansion and breakage.
  • Using a glass cup that has visible chips or scratches—these are stress concentrators.
  • Assuming all ‘glass’ measuring cups are the same; modern Pyrex is soda-lime, not borosilicate.

FAQ

Can I microwave a glass measuring cup with oil?

No, it’s not safe. Oil heats unevenly in a microwave and can superheat, causing the cup to crack or explode. Always heat oil on the stovetop.

Is Anchor Hocking measuring cup safe for hot oil?

Yes, but only if it’s preheated and oil is below 400°F. Anchor Hocking uses tempered soda-lime glass similar to modern Pyrex.

What temperature does glass break with hot oil?

Standard soda-lime glass can break at sudden temperature differences over 100°F. For gradual heating, it can withstand up to 425°F. Borosilicate can handle up to 500°F and sudden changes up to 350°F.

Can I use a glass measuring cup for deep frying?

It’s not recommended for deep frying because the oil can reach 375°F and the cup may be unstable. Use a metal or silicone cup instead.

The Bottom Line

Using a glass measuring cup for hot oil is safe when you choose the right type of glass, preheat the cup, and avoid extreme temperature changes. For regular deep frying or high-heat tasks, a metal or silicone measuring cup is a better investment. Always check your cup’s material—borosilicate is best—and handle with care to avoid burns and breakage.

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