Effects of Mash Temperature
METHODS MADE SIMPLE | Mash Temperatures
As any brewer knows, mash temperature matters a great deal, but the traditional temperatures of regular brewing don’t really apply to brewing NA/LA beers. With some traditional methods, you can expect to see step mashing through various temperatures to increase efficiency and quality of the final beer, but these days with such highly modified malts, a single infusion temperature has become the standard process, depending on the style and fermentability, brewers generally aim to mash between 60-68ºC (140-154ºF).
Different mash temperatures activate different enzyme activity, the two major enzymes brewers are focused on are Alpha (α) Amylase and Beta (β) Amylase. These enzymes promote different aspects to the wort, with β-Amylase favouring a temperature range between 55-66ºC (131-151ºF), this enzyme helps break down starches into maltose and fewer dextrins, resulting in a higher concentration of fermentable sugars and greater attenuation, whereas α-Amylase favours a temperature range of 68-72ºC (154-161ºF), breaking down the starches into smaller chains, creating a more dextrinous and less fermentable wort allowing the β-Amylase to break the starches down further into fermentable sugars. Both enzymes are considered to be fairly active around standard mash temperatures of 65-67ºC (149-152ºF), allowing brewers to create a wort that is largely fermentable.
Mashing above these favoured temperature ranges can denature the enzymes, rendering the wort less fermentable due to the reduces maltose production, by favouring the α-Amylase activity on the high temperature side, we denature the β-Amylase enzyme and produce a wort consisting of more dextrins and less fermentable sugars, resulting in less attenuation and a lower ABV with a greater body and mouthfeel.
With NA/LA brewing, we like to push these temperatures to the extreme to create a less fermentable wort, resulting in an increased body and mouthfeel, maintaining a low abv. My go to temperature to mash is 80ºC (176ºF), I find this temperature creates a great balance of low fermentability and medium to full body/mouthfeel, without any unwanted tannin extraction.
Effects of Mash Temperature
In this experiment, we look to compare 2 different mash temperatures to determine the difference in flavour, colour, fermentability, and body/mouthfeel. We will brew 2 batches of the exact same recipe side-by-side, with the only variable being temperature. 1 batch will be mashed at the higher end of the α-Amylase range at 72ºC (161ºF), and the other batch at a much higher temperature of 82ºC (180ºF), both for 30 minutes each.
For this experiment, we will be brewing an English IPA, a style.
“English IPA”
Batch Size: 22 L
MASH TIME | BOIL TIME | IBU | EBC | EST. OG | EST. FG | ABV |
30 mins | 30 mins | 41.0 | 15 EBC | 1.010 | 1.008 | 0.30 % |
Actuals | 1.013 | 1.008 | 0.70 % | |||
| NAME | AMOUNT | % |
| Simpsons Maris Otter | 500g | 53.3 |
| Simpsons Crystal Light | 180g | 19.2 |
| Weyermann Carapils | 128g | 13.6 |
| Joe White Maltings Light Munich | 109g | 11.6 |
| Simpsons Crystal Dark | 22g | 2.3 |
| NAME | AMOUNT | TIME | USE | FORM | ALPHA % |
| Cascade | 6 g | 30 min | Boil | Pellet | 7.0 |
| Centennial | 5 g | 30 min | Boil | Pellet | 10.5 |
| Fuggles | 5.4 g | 5 min | Boil | Pellet | 4.5 |
| Styrian Goldings | 6 g | 5 min | Boil | Pellet | 5.5 |
| Cascade | 6.5 g | 10 min | Aroma | Pellet | 7.0 |
| Fuggles | 6.5 g | 10 min | Aroma | Pellet | 4.5 |
| Cascade | 35 g | 4 days | Dry Hop | Pellet | 7.0 |
| NAME | LAB | ATTENUATION | TEMPERATURE |
| LalBrew London | Lallemand | 35% (Est.) | 19°C |
| NAME | Amount | Time | Use |
| Whirlfloc | ½ Tablet | 10 mins | Fining Agent |
| Water Profile: Ca2+ 61 | Mg 2+ 2 | Na+ 18 | Cl⁻ 33 | SO₄²⁻ 114 | HCO₃⁻ 43 |
Once the first batch has completed its mash, we remove and squeeze the bag to drain the remaining wort, top up our brew kettle with 2ltrs of water, then check our pre-boil gravity and proceed with the boil.
Once the wort of the first batch has reached a boil, we start the timer for 30 minutes and add our first hop additions, continuing our way through the hop schedule and Whirlfloc. Once the second batch is completed mashing, we then check our pre-boil gravity and proceed with the boil.
Once both of the boils are complete, we take a sample to measure our post-boil gravity, which will be our starting gravity (SG) before transferring the hot wort to our HDPE cube to cool down to pitching temperature overnight.
Once both of the worts have cooled down to our pitching temperature of 19ºC (66ºF), we pre-acidify to 4.6pH with a lactic acid addition and pitch half a pack (5.5g) of Lallemand London yeast into each cube and left to ferment in the fermentation chamber for 7 days.
With 4 days left of our fermentation schedule, we add our dry hop additions.
Once we have ensured we have reached our FG, we cold crash at 2ºC (35.6ºF) for 2 days, then transfer to the kegs for carbonation and conditioning for 2 weeks.
RESULTS
– 72ºC (161ºF) Mash: SG: 1.015, FG: 1.005, = 1.3% ABV
– 82ºC (179ºF) Mash: SG: 1.013, FG: 1.008 = 0.7% ABV
Appearance:
Both have a lovely deep golden/copper colour, with nice clarity. Beautiful foam upon pours with a lasting sticky foam.
Aroma:
Malty, with prominent light toffee/caramel aroma, with complimenting floral and citrus hop aromas.
Taste:
Full bodied, smooth bitterness with a smooth, slightly sweet crystal/caramel malt flavour, delicate floral flavour with a nice orange, and grapefruit citrus taste.
Overall First Impressions:
This is a very nice example of an English IPA, with a great balance of sweet crystal flavours and aromas complimenting the floral and citrus hop flavours and a lovely golden copper like colour. It does lack a little in the bitterness due to the sweetness the crystal malts brings, but an increase in IBUs would correct this. As is, this beer is fantastic and something I could enjoy all year round!
Comparing samples of both beers side by side, both are very similar in all aspects except for taste. They both have the same level of body and mouthfeel, though I noted the 72ºC (161ºF) beer to have a higher perceived sweetness. I feel this increase in body and sweetness comes from the increase in alcohol in the lower temperature beer, matching the body of the higher dextrinous beer mashed at 82ºC (179ºF).
By having two exact batches with the only variable being mash temperature, we could certainly expect to see a difference in our wort composition. What we found was that the higher mash temperature yielded a lower original gravity of 1.013, whereas the lower mash temperature yielded a higher original gravity of 1.015, which points us towards the belief that we denatured more of the active enzymes the higher the temperature reaches, resulting in a lower conversion of the starches, and creating a lower gravity wort. Which in turn results in a lower abv beer.
With both beers having the same fermentation schedule and dry hop amounts, we could also note a difference in final gravity between both beers. The high temperature mash beer finishing with a higher final gravity at 1.008 and the lower mash temperature at 1.005, meaning we observed a difference of 0.003.
What we find with the higher mash temperature, is that not only are we creating a lower starting gravity, but we are also creating low fermentability, resulting in low attenuation and a higher final gravity, making a lower abv beer. From this experiment, we can conclude that the high mash temperature is the preferred temperature to assist in developing non-alcoholic beer.