Experiment: Amplifying Thiols with Propper Phantasm

We’re always looking for ways to dial in thiols to create the ideal tropical burst of grapefruit, passion fruit, and guava. Recently, Omega Yeast partnered with Phantasm to create Propper Phantasm, a liquid thiol precursor sourced from New Zealand ingredients. Similar to the precursors that exist in malt and hops, pairing Propper Phantasm with Thiolized® yeast amplifies the levels of 3‑sulfanylhexanol (3SH) and its acetate ester 3‑sulfanylhexylacetate (3SHA). Brewers can use Propper Phantasm to dial in thiol intensity in their existing recipes by only changing one variable in fermentation. Science!

To test it out, we created an experiment based on a recipe with only a modest whirlpool charge of Citra hops (also rich in free thiols). We split the batch three ways: 

• British V (OYL-011)
• Cosmic Punch (OYL-402)
• Cosmic Punch (OYL-402) + Propper Phantasm

Adding Propper Phantasm to cooled wort along with the yeast pitch at a rate of 250 mL/5 bbl will increase the beer’s thiol levels by 100%, but we wanted to know if the numbers matched up with the overall perceived difference in thiol intensity. Let’s see how it played out. 

Our sensory panel did a blind tasting of each beer and ranked thiol intensity on a scale of 0 – 6 (0 = control; 6 = high). After the initial sensory tasting, we created a series of calibration samples by spiking the British V control batch with 3SH to establish standards for no, low, medium, and high thiol intensities as follows: 

• 0 — Control (no 3SH)
• 2 — Low (500 ppt 3SH)
• 4 — Medium (1000 ppt 3SH)
• 6 — High (5000 ppt 3SH)

The panel then tasted and scored each beer again along with the calibration samples to provide recognized set levels. Both rounds of tasting were blind, but having the set of spiked standards allowed our panel to challenge or confirm their previous rankings. Evaluating thiol levels is a difficult exercise because its easy for your olfactory senses to get blown out and leave you disoriented. (The sensory threshold for 3SH is 60 parts per trillion (ppt), so even a low level thiol character of 2 is quite high.)

After it all shook out, we deducted the value of the perceived thiols from the OYL-011 control batch to account for any thiol contributions from the malt or the hops. Where did that leave things? Before calibration, our panel found adding Propper Phantasm at a rate of 250 mL/5 bbl provided a 69% increase in perceived thiol character. After comparing the beers against the calibration samples, that bump increased to 78%. All in all those perceived thiol impacts came pretty close to the actual levels created by adding Propper Phantasm. Determining thiol levels by tasting and smelling alone can be tricky business because their aroma is so potent and it can be easy to be overwhelmed in the process. 

The experiment also showed that using Propper Phantasm with Cosmic Punch allows brewers the option to land in a thiol sweet spot of ~1000 ppt of 3SH. This could be a good play if you’re looking for more thiol impact than you can achieve with Cosmic Punch alone (600 ppt 3SH), but you’re not looking for results as potent as what Helio Gazer provides (6,000+ ppt 3SH).