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The Flash Mash

The Flash Mash

By Greig McGill

Apologies to any international readers of this humble Brewshop blog who are unfamiliar with the term “flash” in this context. It’s a UK/Aussie/Kiwi-ism, and is often used the same way as the more American term “bling”. That is to say, a little bit fancy!

Mashing seems like a fairly pedestrian part of the brewing day, right? Soak those grains at the right temperature for the optimum amount of enzymatic activity to achieve the desired body and fermentability of your resultant wort. What exactly can you “flash up” about that? Well, there have been quite a few advances in techniques and knowledge around the humble mash over the last few years, and there’s now quite a bit you can do to tweak, optimise, or just play around with your mash to achieve a better, more satisfying, more you brew day.

We’ll start with some terminology. Mashing in (also historically known as doughing in) is the process of blending the hot liquor (water and required water treatments such as acid, minerals, etc.) and grains to create a homogenous blended porridge-like amalgamation known as the mash. Mash conversion is the time where the mash is sitting at the desired temperature optimised for the enzymes present in the grist (the crushed grain mix) to break down the long chain starches into fermentable sugars. This stage may consist of several sub-stages in a multi-step mash differentiated by temperature and enzyme activity, and these may involve removing part of the mash and boiling it, then adding it back to raise temperature for the next stage. This historic method is known as decoction mashing, and is not widely practised due to modern malting techniques removing the need for it. Holy wars still rage over whether it imparts character unobtainable in other ways, however. Mashing out is an optional step, often practised simply to ensure consistency, where the temperature is raised to the point where all enzymes are denatured and any further conversion is prevented. This “locks in” the desired mash profile, without any further conversion creep during the final phase - lautering. Lautering is the process of using the grain bed (assisted by a false bottom in the lautering vessel) to filter and separate the sweet wort from the spent grains. Lautering often involves a sub-step called sparging, where extra water is sprinkled over the grain bed to rinse as much residual sugar from the mash as possible. This sweet wort is then boiled and… well, you know the rest of the process - I hope!

This Is The Way.

Or at least, it has been for centuries. What has modern scientific investigation taught us, then, that we can use to tweak this historical and well-practised method? Lots!

Fun With Enzymes

The recent Brut IPA style circa 2018 may have been a bit of a flash in the pan, but it did introduce the home brewing world to the possibilities inherent in adding extra enzymes to our mash to achieve certain goals. In the case of the Brut IPA, that result was extra starch conversion via the amyloglucosidase (and say it with me… “Am-ih-loh-glue-koh-sid-aze”) enzyme. With amyloglucosidase (thank you Larry Tesler, patron saint of copy/paste) we brewers could really dry out our beers, leaving minimal residual sweetness to get in the way of those hops we craved. Sadly - at least to me - the style never really took off, as few embraced it beyond a fad and even fewer managed to make a great example of the style. Urbanaut’s Copacabana was one of the best, in my humble opinion, and is still around to this day if you want to see what that particular enzyme can bring to a mash, and thus to a beer. Enzyme engineering may have a bright future in brewing, allowing us to perform such witchcraft as creating a fermentable beer without using any base malt, or malts with diastatic power (enzymatic potential) in the mash. 100% unmalted wheat ale anyone? Other recent advances in enzyme engineering are tied up with the freeing of bound thiol precursors in malted barley. These thiol precursors can then be converted with a thiolized yeast strain to produce many aromas similar to tropical hop flavours. Of course, getting thiolized yeast strains in NZ might prove tricky for a while given our country’s archaic and outdated legislation around genetically modified anything, but we’ll get there eventually!

Non-Traditional Grists

As discussed above, the use of engineered enzymes in the mash can allow expanded use of non-traditional grains in our grist. This could be a huge boon for making gluten free or historically-influenced beers, as you could easily mash with rice, sorghum, corn, buckwheat, millet, etc. all in an unmalted state, and simply use additional enzymes in order to obtain fermentable sugars. Bored with the typical beer profiles available to you via standard malted barley, wheat, oats, and rye? Go hang out in your local Bin Inn for a bit and let your imagination run wild! Remember to save me some for tasting…

Mash Filtration

Traditionally only available to the pros, if you’re feeling particularly handy, you could build yourself a mash filter. “Simply” adapt a brew-in-a-bag system to include a mechanical press, to squeeze every last drop out of your grain bag. This technique requires a lot of setup and cleaning at a pro level, but at a homebrew level is simply an extension of the “squeeze the bag” method of wort extraction in BiaB brewing, and will result in high efficiency, clearer wort, and easier cleanup with most of the moisture removed from the grain bag.

Mash Hopping

This one is quite old-school, yet thanks to those thiolized yeast strains I mentioned earlier, is coming back into vogue. Long practised traditionally by brewers in order to help with grain bed stability during lautering, as well as add more hop depth to a beer’s flavour, mash hopping is now cool again for a different reason. It turns out that several hop varieties are very high in bound thiol precursors, and that the enzymatic activity in the mash can help free them, making them available to the yeast during fermentation. Again, use of these yeasts isn’t (legally) possible yet in New Zealand, but there are companies working on non-GM versions of thiolized yeast strains via sporulation leading to sexual reproduction, then natural selection for the particular genes required, as well as attempting hybridisation with other strains possessing this capability. Hopefully we will see the fruits of this work soon, while we (im)patiently wait for the law to catch up to reality!

High Pressure Mashing

This one fascinates me, as it’s something that’s only really practical at the homebrew level, making it a tool just for the hobbyist! This technique involves conducting the mash in a pressure cooker type environment, leading to simple gelatinisation of the starches in the grains and thus, at least theoretically, a more rapid enzymatic conversion. The only problem? The science so far says that it’s not that much more efficient than a typical mash, resulting in roughly the same sugar extraction. The original paper was published in 2002, and (probably due to the conclusion) has had very little further development, though I am aware of some home brewers messing with the process and claiming some interesting results. One to try if you’d like to be at the forefront of modern brewing research!

I’d love to hear from anyone who has tried some advanced mashing techniques. Perhaps this post needs a reader followup article… mashing in the wild!

Mash on friends.