Behind the Label: HPLC vs Spec

At Topp’s Hops, we know that every hop cone carries a unique chemical signature, influencing how brewers craft flavors and aromas. To capture these unique profiles, we rely on two analytical methods: High-Performance Liquid Chromatography (HPLC) and UV Spectrophotometry (Spec). Both methods are powerful tools for uncovering the nuances within our hops, but they differ in their approach and the insights they reveal. This article dives into what HPLC and Spec are, how they evolved, and what each brings to the table so that you, the brewer, can decide which fits your recipe development best.

What is HPLC? Breaking Down the Science

High-Performance Liquid Chromatography (HPLC) is essentially a high-speed sorting process. Imagine lining up all the compounds in a hop sample by weight, structure, and chemical behavior—HPLC does precisely that. It separates and identifies individual compounds, such as alpha and beta acids, which are crucial for bitterness and aroma. By pushing a liquid sample through a pressurized column, HPLC allows us to capture a detailed breakdown of the compounds, ensuring we can pinpoint exactly what’s in your hops. With this data, brewers can fine-tune their recipes, hitting the perfect bitterness and balance (American Society of Brewing Chemists, n.d.).

What is Spec? Simpler, Faster, and Still Effective

Spectrophotometry, or Spec, takes a different approach. Instead of individually analyzing every compound, Spec measures how much UV light hop compounds absorb at specific wavelengths. This light absorption reveals alpha and beta acid content but doesn’t separate the compounds. The result? A less granular, yet still valuable, analysis that’s quicker and often more cost-effective. Spec offers a fantastic snapshot of hop potency, allowing you to make efficient assessments without the wait or cost of HPLC analysis (European Brewery Convention, n.d.). Spec is what you will most often see on bag labels when it comes to hop companies based in North America. This being the industry standard, while perhaps less precise, means that majority of craft recipes in North America will be based off these values. 

A Brief History: How These Methods Came to Be

Both methods have deep roots in chemical analysis, though they evolved for different purposes. HPLC burst onto the scene in the 1970s as an advancement over earlier chromatography methods, allowing chemists to get a clearer and faster look at complex mixtures. Its ability to provide precise, repeatable data quickly made it a favorite in hop analysis, giving brewers a tool that shows hop potency and breakdown in detail (Howard, 2015).

Spectrophotometry, however, has been around since the early 20th century, originally used for broader chemical applications. By the mid-1900s, it had found its way into hop analysis, where it became a go-to for routine quality checks. Brewers who want a quick reading on alpha and beta acids found it a valuable, efficient option, despite its broader measurements (“History of Spectrophotometry,” 2000).

How They Differ: The Precision of HPLC vs. the Speed of Spec

HPLC and Spec are like two sides of the same coin. HPLC provides a precise, compound-specific reading, while Spec delivers a faster, composite snapshot. Where HPLC is ideal for detailed measurements of alpha and beta acids, Spec offers a more accessible option, especially for quality control checks that require quicker turnarounds. Neither is strictly “better”—the choice depends on the level of detail a brewer needs. For those creating intricate hop profiles or targeting exact bitterness levels, HPLC’s precision can be invaluable. For a faster, simpler snapshot, Spec can more than suffice.

The Role of Standards: ASBC and EBC Methods

The American Society of Brewing Chemists (ASBC) and the European Brewery Convention (EBC) have each developed methods to standardize these analyses, making results reliable across the industry. At Topp’s, we use ASBC Hops 14 and EBC 7.12 for HPLC testing, both of which focus on alpha and beta acids, giving brewers confidence that the hops are exactly as advertised. For Spec, we turn to ASBC Hops 6, a recognized method for spectrophotometric alpha acid measurement. By adhering to these standards, we ensure that brewers everywhere are speaking the same language when it comes to hop analysis (“ASBC Methods of Analysis”).

Making Your Choice

With COAs for both HPLC and Spec, Topp's Hops offers brewers the flexibility to choose which analysis fits their needs best. Whether you’re diving deep into the exact alpha acid profile for a precise bitterness or seeking a quick snapshot to assess potency, understanding HPLC and Spec enables you to use hops to their fullest potential. By knowing what each method can reveal, you’re equipped to tailor hop profiles to achieve that perfect brew.

References: 

American Society of Brewing Chemists. (n.d.). ASBC methods of analysis. Retrieved from https://www.asbcnet.org/Methods/Methods/Methods.aspx

European Brewery Convention. (n.d.). Analysis of alpha and beta acids. EBC analysis methods. Retrieved from https://www.ebc-methods.com/

Comparative analysis of HPLC and spectrophotometric methods for hop acids. (2014). Journal of the Institute of Brewing, 120(2), 176-182.

History of spectrophotometry. (2000). Encyclopedia of Analytical Chemistry. Wiley.

Howard, A. (2015). The evolution of HPLC in brewing. Modern Brewing Techniques, 32(4), 85-92.