This 2023 study created sulforaphane from broccoli seeds at room temperature using a yeast strain that expressed myrosinase enzyme:

“Myrosinase harboring high glucoraphanin-hydrolyzing activity is the key to prepare sulforaphane efficiently. Almost all the reported exogenous myrosinases are extracted obtained from plants by complex steps. In our previous study, it was proved that a Yarrowia lipolytica 20–8 carrying an Arabidopsis thaliana-derived myrosinase gene can be applied to hydrolyze glucoraphenin for efficient preparation of sulforaphene.

Before being evenly crushed, broccoli seeds were incubated at 100 ℃ for 1.5 h to eliminate endogenous myrosinases and epithiospecifier protein. One unit (U) of glucoraphanin-hydrolyzing activity was defined as the amount of enzyme that hydrolyzes glucoraphanin into 1 μmol glucose per minute.

Yeast whole-cell catalyst of Y. lipolytica 20–8 could yield 10.32 mg (58.22 μmol) sulforaphane from 1 g dried broccoli seeds within 15 min under mild reaction conditions with a conversion rate of 99.86%. This yeast whole-cell catalyst could be employed for efficient and reusable preparation of sulforaphane.”

https://www.sciencedirect.com/science/article/pii/S2590157523001104 “High-level and reusable preparation of sulforaphane by yeast cells expressing myrosinase”

These researchers referenced their 2021 study where they did the same thing with sulforaphene and radish seeds. That caused English-translation confusion in the Abstract and Conclusion sections.

This study’s yeast strain price and/or availability may preclude use for home sprouting. Arabidopsis thaliana is a road-side weed in Eurasia, though, so who knows what a functioning market could deliver?

3-day-old broccoli sprouts have the optimal yields heated broccoli seed powder at 55° C for only 5 minutes – which sufficiently inactivated epithiospecifier protein – vs. this study’s 1.5 hours at 100° C. Would you do that for five minutes, mix in yeast, then wait 15 minutes for a better sulforaphane yield?