Sirem Hops: Profile & Substitutions

Description

Sirem is an exquisite and rare clonal selection of the traditional Saaz family, originating as a clone of Zatecky Krajovy at the Hop Research Institute in Zalec. Known by several aliases in the international trade—including Aurum, Bohemian Red, and Saaz—it is a cornerstone of the "Bohemian Red Hop" tradition, distinguished in the field by its striking reddish stems. Due to its historically poor growth rate and low yields, Sirem remains a boutique variety grown on very limited acreage. Despite these agricultural challenges, it is prized for its historical significance and its ability to produce the "super-premium" character required for world-class, authentic continental pilsners.

The sensory profile of Sirem is the embodiment of the "Noble" hop ideal: exceptionally mild, pleasant, and sophisticated. It leads with a primary, "old-world" bouquet of soft floral notes and sweet hay, immediately followed by the classic spicy-earthy undertones that define the finest Bohemian hops. As the profile develops, brewers will find a remarkably clean and delicate bitterness that integrates seamlessly into light malt backbones. Thanks to its high humulene-to-caryophyllene ratio and low cohumulone levels, Sirem provides a rounded, non-lingering finish and a refined herbal aroma, making it the definitive choice for brewers seeking a polished and professional aromatic depth.

Substitution Tip

If you can't find Sirem, the best alternatives are Saaz or Sládek.

At A Glance

Profile Floral, Sweet Hay, Spicy, Earthy
Purpose Aroma
Alpha Acid 2.7 - 4.4%
Substitutes Saaz, Sládek
Pairs with Premiant (for a firmer/clean bittering base), Saaz (to reinforce the traditional spice), Sládek (for a more modern fruit-forward lift)
Beer Styles Pilsner, Bohemian Lager, European Pale Lager

General Information

Country Czechia
Aliases Aurum, Bohemian Red
Storage Stability
Retains 54 - 60% alpha acid

Brewing Chemistry (Acids & Oils)

Alpha Acid 2.7 - 4.4%
Beta Acid 2.8 - 3.5%
Cohumulone 21.0 - 25.0%
Total Oil 0.2 - 0.8 ml/100g
Myrcene 20.0 - 40.9%
Humulene 20.3 - 26.5%
Caryophyllene 5.6 - 6.6%
Farnesene 12.2 - 20.8%

Growth & Cultivation

Yield 74 - 192 pounds/acre
Maturity Early
Susceptible Downy mildew (moderate)
Growth Rate Poor
Cones Small, delicate, and rich in the fine essential oils characteristic of the Saaz lineage
Ease of Harvest Moderate; while it is mechanically harvestable, its low vigor and short side-arms require attentive
Sex Female
Leaf Color Dark green
Side Arm Length 6 - 10 inches

Discovery Tags

Flavor/Aroma
Earthy Floral Spicy Sweet Hay
Variety Name
Premiant Saaz Sládek
Beer Style
Bohemian Lager European Pale Lager Pilsner
Usage
Aroma
Origin
Czechia
Breeding/Supplier
Hop Research Institute
Last Updated
  • 2026-04-03 09:58:51
Source(s)

Hops Catalog

Navigating This Profile
  • The Stats: Use the Purpose and Alpha % to understand the hop's bitterness and aromatic strength.
  • Discovery Tags: Scroll down to find clickable tags for Flavor, Origin, and Usage.
  • The Network: Click any tag (like #Citrus or #New Zealand) to instantly view every other hop in our catalog that shares that trait.
Discovery Tag Spotlight

  • #Noble (Classics)

    Back to the roots. European "Noble" hops are the elegant, low-bitterness varieties that defined Pilsners and Lagers for centuries. Explore the spicy, floral heritage of the Old World. Explore #Noble Hops!
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Did you know?
  • Dwarf variety hops grow shorter in height than traditional varieties but, importantly, produce the same yield. This combination makes harvest easier.
Explanations
  • Storage: is based on the percentage of alpha acids remaining after 6 months at 20*F.
  • Oil composition percetages are based on the total percentage of oil in the hop. Example: 10 - 20% means that for the specific oil it is 10 - 20% of the overall oil make up.