Classic Series (Glass Jar)
One of the last countertop blenders with a real glass jar - the blend path is glass, stainless blade, and a rubber sealing ring; only the lid is plastic.
Plastic-free verdict: Minimal plastic contact
The jar is glass (Oster's thermal-shock-resistant "Boroclass") and the four-point blade is stainless steel, so the part of the blend where friction and heat generate microplastics - the jar wall and blades - is glass and steel, not Tritan. The seal between the jar and blade base is a food-grade EPDM rubber ring. The lid and its removable center cap are plastic; when the jar is full or you pour, liquid does contact the plastic lid, so this is not silicone-only. But compared with a Tritan-jar blender it puts far less plastic in the food path - the lid is the only plastic contact, not the whole jar.
Verification: Manufacturer confirmed · reviewed 2026-07-05
What it's made of
| Part | Material | Food contact |
|---|---|---|
| jar Oster "Boroclass" thermal-shock-resistant glass jar; exact glass chemistry (borosilicate vs tempered soda-lime) not definitively documented - treated as glass either way | Soda-Lime Glass | Yes |
| blade Crush Pro 4 four-point stainless steel blade | Stainless Steel (304 / 18-8) | Yes |
| jar-to-blade sealing ring food-grade EPDM rubber gasket between the jar base and blade assembly | EPDM Rubber | Yes |
| lid plastic lid; contacts liquid when the jar is full or when pouring | Plastic (other / unspecified) | Yes |
| lid center / filler cap removable plastic measuring/filler cap in the lid | Plastic (other / unspecified) | Yes |
The archetypal all-metal-drive glass-jar blender, sold for decades and still available new. A heavy Boroclass glass jar sits on a threaded base that holds the stainless blade and a rubber sealing ring; the motor base uses an all-metal drive coupling (10-year all-metal-drive warranty). Because glass jars largely vanished from the blender market over blade-speed liability, this legacy line is a genuine recommendation path for avoiding a Tritan jar.
Pros
- Real glass jar and stainless blade - no Tritan in the friction/heat blend path
- All-metal drive; inexpensive and widely available
- Glass jar is dishwasher safe and non-reactive
Cons
- Lid and center cap are plastic and do contact liquid when full/pouring
- Glass jar is heavy and breakable
- Not as powerful or smooth as a high-end blender
Notes
- Sold under several model numbers (e.g. Classic Series Heritage, BLSTAJ 6-cup glass jar); look for the 6-cup Boroclass glass jar SKUs specifically - Oster also sells plastic-jar models
- Replacement glass jars, stainless blades, and rubber sealing rings are cheap and widely available
Categories: Blenders
Sources
Every material claim above is backed by these. This is the scattered info we centralized.
- manufacturer https://www.oster.com/blenders/kitchen-blenders/oster-classic-series-heritage-blender-with-6-cup-glass-jar-stainless-steel/SP_395331.html manufacturer lists a 6-cup Boroclass glass jar and a Crush Pro 4 stainless steel blade with an all-metal drive
- review https://www.goodmans.net/i/2846/gray-blj-seal-fits-oster-blenders.htm replacement-parts vendor identifies the Oster jar-to-blade sealing ring as food-safe EPDM rubber, seated between the top of the blade and the bottom of the jar