Strata

Strata comes from the breeding programme of Oregon State University (OSU) and the hop merchant Indie Hops of Portland. OSU researcher Shaun Townsend, the technical lead of that programme, calls Strata the first aroma variety to reach the market from the collaboration.

According to Indie Hops, Strata was 'born' in 2009, as offspring of an openly pollinated Perle plant on an OSU trial field in Corvallis: the mother is therefore known, the father not. During the trials the plant was called 9-1-331, X-331 for short. The American agricultural statistics still list the variety as 'Strata®, OR 91331'.

Indie Hops put Strata on the market in 2018. The word strata means 'layers'. According to Townsend, Indie Hops chose it because the variety gives different flavours depending on when the brewer adds it.

Scientific research on Strata is mainly about thiols: sulfur compounds that you can smell in tiny amounts. In a 2024 study by the Technical University of Munich (with a researcher from the hop merchant Hopsteiner) on 32 hop varieties, Strata, together with Citra and Mosaic, was among the varieties rich in both measured thiols: 4MMP, which smells of blackcurrant, and 3MH, with an aroma of grapefruit or rhubarb. A second study, by researchers from the hop merchant Hopsteiner, with 250 samples of 97 varieties, put Strata in the highest category for 'thiol impact'. These levels do fluctuate strongly by growing region, harvest year and picking time.

Indie Hops describes Strata as passion fruit, melon, strawberry, grapefruit, 'rock concert cannabis' and dried chilli pepper. The breeder Townsend says the fresh cones were disappointing at first: they smelled unpleasant, almost sour, with tropical fruit and an earthy weed smell underneath. After drying, that sour note was gone.

The moment of addition also seems to count, the breeder writes. With late additions in the hot phase and with dry hopping in the middle of fermentation, more passion fruit and strawberry come forward; with dry hopping after fermentation, more pink grapefruit and the weed-like note.

Strata is mainly a hop for aroma and flavour: late in the kettle, in the whirlpool and when dry hopping. OSU calls it an aroma hop, although according to the breeder it contains 12–15% alpha acids. Indie Hops supplies it in different forms: - ordinary pellets and whole hop cones; - pellets of concentrated lupulin (Strata Cryo and Strata CGX); - a hop extract with extra hop oil (Strata HyperBoost).

According to the breeder, Strata suits hazy IPAs, West Coast IPAs (for example together with Chinook or Cascade) and pale ales. Lager brewers also surprised Indie Hops: in those, mainly the strawberry comes forward. The breeder suggests that this may be due to the German Perle in the parentage.

None of the sources we consulted say which hop resembles it. In both thiol studies, Strata did fall in the same group as Citra and Mosaic, but that is only about those thiols, not about the whole aroma.

In 2010, OSU laid out a breeding garden near Corvallis. A third of the seedlings first went onto a low trellis of about 1.8 metres. The best went in 2011 to the ordinary trellis of almost 5.5 metres; X-331 was one of them. Small trial plots followed on two hop farms in the Willamette Valley, which have been growing for generations, and finally plots of about an acre (0.4 hectares). Indie Hops distributed that hop among about a hundred brewers. On a specification sheet from the merchant Haas, 2009 is given as the year of release; according to Indie Hops, 2009 is the birth year of the plant and Strata came on the market in 2018.

In Oregon, Strata stood at 839 acres in 2023, about 340 hectares. In 2025 that was only 326 acres, about 130 hectares.

A good starting point: a hazy IPA or pale ale in which Strata plays the lead. Smell first. If you recognise passion fruit, strawberry or pink grapefruit, with something earthy and 'dank' underneath, that is the profile the breeder describes. Then try a lager with Strata: according to the breeder, mainly the strawberry comes forward in that.

Hop aroma is fragile. So drink such beers fresh and store them cool.