Short mash times

[orlando]

If one presupposes that saccharification is the only process in the mash tun, then it is reasonable to assume 60 minutes will be adequate for most simple recipes.

Brewing with low calcium level has the potential of limiting beta amylase activity to less than the optimal period, so those brewers might readily assume there is no advantage to mashing for a longer period.

A high temperature mash can achieve close to total conversion in around 10 minutes. Getting the wort to ferment is then the problem.

As per the PeeBee advice in "Alcohol free (i.e. low ABV) beer thread" I have tried several experimental low ABV brews (about 5 now) 30 min mashes at 74 degrees, most recent 2kg Munich, 300gm Crystal and 200gm Malted oats for 27 litres into FV. 88% mash efficiency in 26 litres mash water (from GF calculator). 0.9% ABV with S-33 bottled at day 4.

I know that is idiosyncratic and atypical of a standard brew, but thought figures may be useful especially if you're aiming for a lowish ABV beer? My limited experience suggests I get lowest efficiencies with my largest grainbills.

Presumably no sparge?

[bitter_dave]

Thanks Eric / Kingfisher!

As per the PeeBee advice in "Alcohol free (i.e. low ABV) beer thread" I have tried several experimental low ABV brews (about 5 now) 30 min mashes at 74 degrees, most recent 2kg Munich, 300gm Crystal and 200gm Malted oats for 27 litres into FV. 88% mash efficiency in 26 litres mash water (from GF calculator). 0.9% ABV with S-33 bottled at day 4.

I know that is idiosyncratic and atypical of a standard brew, but thought figures may be useful especially if you're aiming for a lowish ABV beer? My limited experience suggests I get lowest efficiencies with my largest grainbills.

Yes, I want to make tasty but fairly low abv beer.

It sounds like a thin mash might be the way to go if it’s going to be short in duration? At the moment I’m mashing on the stove with around 2.5 litres per 1 kg of malt. I then tip (very carefully!) the contents into a small fermenting bin with holes drilled in the bottom, which is suspended above my burco boiler with a cake rack to allow it to drain in. High tech stuff! I then sparge it with 1 pint jugs of water (about 1.5 times the amount of mash water). If I were to move to a thinner mash I’d have to do it in the burco in a mashing bag, which I could potentially do.

[bitter_dave]

Ok, so I did a bit of experimenting this morning...

I made a mild using a 30 minute mash and a 30 minute boil, mashing in my Burco boiler in a standard Ritchies mashing bash. I kept the quantity of grains quite low and supplemented this with a kilo of Dried Malt Extract in the boil. The recipe was:

2 Kg Mild Ale Malt
450 grams Pale Crystal
250 grams Dark Crystal
150 grams Chocolate Malt
1 kg Pale DME in the boil.

19g Fuggles at 30 mins = 9 IBU
18g Goldings at 30 mins = 7 IBU
30g Goldings at 10 mins = 6 I BU
(Total = 19 IBU)

I mashed the grain in 24 litres of water for 30 mins. Mash temp settled at about 69 and lost a couple of degrees over the half hour. Much smaller difference between striking temp and mash temp than usual given the quantity of water!

I then lifted the bag out and sparged it a bit.. I did this while the boiler was heating so it didn't add any additional time

The rest was fairly standard brew day. Cooled wort with immersion chiller, put in fermenter and added yeast. I got an OG of about 1.042 which was higher than I was expecting given the short mash.

This seems to represent an efficiency of 75% according to Wheeler's beer engine, which I would be happy with under normal circumstances. A lot of gunk made it into the fermenter though, perhaps because I mashed in the boiler? Anyway, I'll fine it with gelatin before it goes into the barrel.

The next question is whether it will ferment into reasonable beer! I used Mangrove Jack's Empire Ale yeast because I had a spare one lying around. I've only ever used this on extract brews and I've found it to be a low attenuator, so I would expect a fairly high FG (but I'm happy with that, obviously within reason).

Currently sitting in the beer fridge set to 20 C.

[bitter_dave]

[Jef]

Not sure that I can add much to the previous posts, except to say that I’ve done iodine tests on mashes at 15, 30 & 50min intervals, just out of interest. There was more of a blue-black colour (more starch present) at 30 mins than at 50 mins. Personally I am brewing for fun and interest rather than efficiency. I’ve made a pilsner, maybe 2, on a 30min mash, without a discernable ABV or taste difference, so reverted to 50min mash as standard until I have the opportunity to test some more. Would a shorter mash potentially reduce tannins and be better for some styles?

[orlando]

Would a shorter mash potentially reduce tannins and be better for some styles?

No. Mash pH is far more likely to have an influence on that than time.

[bitter_dave]

Quick update about the quick mash and boil - I did half hour mash and half an hour boil (see above).

The beer stopped fermenting at about 1020. I tried to nudge it along a bit more with a stir, new yeast and slight increase in temp but it didn't do much. I crash cooled, fined and barrelled it. Works out about 3% ABV (which is not a problem for me). I had some of the finished beer on Friday and Saturday night. It's perfectly drinkable but nothing special. Despite the high FG it does not taste sweet, although I think it would be better if it had fermented a few more points. Might benefit from a bit more time in the barrel perhaps, we'll see. In any case, half an hour mash and boil makes beer!

I'm not sure how much I can attribute the low attenuation to the short mash time, given that the mash temp was on the higher side and the empire ale yeast is a low attenuator. However, the short mash time was perhaps a factor based on what people have said. Next time I think I'll go for 45 mins mash and half an hour boil and see what happens.

[Kingfisher4]

If one presupposes that saccharification is the only process in the mash tun, then it is reasonable to assume 60 minutes will be adequate for most simple recipes.

Brewing with low calcium level has the potential of limiting beta amylase activity to less than the optimal period, so those brewers might readily assume there is no advantage to mashing for a longer period.

A high temperature mash can achieve close to total conversion in around 10 minutes. Getting the wort to ferment is then the problem.

As per the PeeBee advice in "Alcohol free (i.e. low ABV) beer thread" I have tried several experimental low ABV brews (about 5 now) 30 min mashes at 74 degrees, most recent 2kg Munich, 300gm Crystal and 200gm Malted oats for 27 litres into FV. 88% mash efficiency in 26 litres mash water (from GF calculator). 0.9% ABV with S-33 bottled at day 4.

I know that is idiosyncratic and atypical of a standard brew, but thought figures may be useful especially if you're aiming for a lowish ABV beer? My limited experience suggests I get lowest efficiencies with my largest grainbills.

Presumably no sparge?

Sorry, missed this. Yes, indeed, no sparge.