T90 vs T45 pellets also: Type 90, Type 45, Standard hop pellets
The standard hop pellets. T90 keeps 90% of the cone material; T45 removes more, concentrating lupulin.
What it is, in plain English
Almost every craft beer made in the last 40 years has used T90 or T45 hop pellets. The 'T' is for 'Type' and the number is the percent of original plant matter retained in the pellet. T90 means 10% has been removed during processing — most of the moisture and a bit of stem material. T45 means 55% has been removed, concentrating the lupulin and reducing the green plant matter. T45 is functionally similar to early-era cryogenic pellets, just produced via mechanical sieving rather than cold separation. T90 is the dominant format in modern craft brewing.
The technical version
After harvest, hop cones are dried, baled, then ground into a fine powder. The powder is pressed through a die to form the familiar dark-green cylindrical pellet. T90 retains 90% of the original cone matter. T45 mechanically separates and concentrates the lupulin-rich fraction during processing, producing a denser, more aromatic pellet at 45% of original weight.
How brewers use it
T90 is the workhorse: dose by recipe, store cold, use within ~12 months for best aroma. T45 is dosed at roughly half rate of T90 (similar to Cryo Hops) and offers some of the same benefits — less vegetal extraction, less polyphenol. The cryogenic pellets (Cryo, Lupomax, Amplifire) are essentially next-generation T45s, with cleaner separation thanks to the cold-and-inert-atmosphere processing.
Who uses it
Every brewery uses T90. T45 is less common in craft, more common in industrial and traditional European brewing.