Does the mashing temperature affect mash efficiency?

[Miles_1111]

Just brewed a batch of IPA the day before yesterday. As you can see the actual OG is much lower than the EST OG:
Est Original Gravity: 1.060 SG ( 14.74P ) Measured Original Gravity: 1.052 SG ( 12.86P )

My average mash efficiency is around 72%, but this time was only 62%. The mashing temperature was quite low, about 63.6 ℃ ( 146.48℉ ), so is this the reason why the mash efficiency is lower than my average? As in previous batches the mashing temperature were from 65℃ ( 149℉ ) to 67 ℃ ( 152.6℉ ). Or there might be other reasons that I have noticed yet.

Thanks for all the help.

 

[Lefou]

Mash temperature definitely influences your conversion rate but a lot depends on your grain, too.
I've done one single infusion mash that varied no more than +/-2F at 158F and it yielded a 52% brew house efficiency. My typical efficiency runs about 68-70% for most brews, and I know in that one instance it had a lot to do with how old my grain was and how it was stored.

 

[eetu]

It could be multiple things.

- Cooler mash needs more time to do it's thing.
- It could be bad crush.
- I do BIAB, and water to malt ratio has signifance.
- Malt age, especially if stored crushed.

What was different to other mashes other than temperature?

 

[dmtaylor]

Mash temperature could be part of it, but probably not all of it. I wouldn't recommend mashing below about 148 F (about 64.5 C) unless you extend the mash time to 90 minutes or more. How long did you mash? If just for an hour, yes, that will have some effect. If longer, probably not so much.

Who usually mills your grains? Who milled the grains this time? Any changes in mill gap settings?

 

[CJ-3]

As a side question, did you perform a starch test after the mash to check the conversion was complete?

 

[n3lson1]

Mash temperature can effect your efficiency but more so you will notice it on the back of the final gravity.

 

[RM-MN]

You left out a couple critical pieces of information. Was the crush of the grain identical. The first 3 causes of low mash efficiency are:
The crush, the crush, the crush. All other factors are less.
The second piece of info missing is the mash period. While most often the mash period is 60 minutes, that period is related to the crush and the mash temperature. With my very finely crushed grains, my mash period for full conversion and extraction of flavors at 156F can be as short as 20 minutes. Milling coarser, I might need 60 or more to get full conversion. Mashing cooler will take longer too. Alpha amylase works fast, beta much slower.

 

[Miles_1111]

Grain crush is very similar to before, mashing time is always 60 minutes. I guess apart from temperature, this time I got the grain from a friend rather than bought from the shop where I always got the malt. I did not ask the friend how long is the grain been stored. Maybe this is the main reason? Seems temperature isn't a big influencer in the low efficiency...

 

[Miles_1111]

It could be multiple things.

- Cooler mash needs more time to do it's thing.
- It could be bad crush.
- I do BIAB, and water to malt ratio has signifance.
- Malt age, especially if stored crushed.

What was different to other mashes other than temperature?

Grain crush is very similar to before, mashing time is always 60 minutes. I guess apart from temperature, this time I got the grain from a friend rather than bought from the shop where I always got the malt. I did not ask the friend how long is the grain been stored. Maybe this is the main reason? Seems temperature isn't a big influencer in the low efficiency...

 

[Miles_1111]

Mash temperature could be part of it, but probably not all of it. I wouldn't recommend mashing below about 148 F (about 64.5 C) unless you extend the mash time to 90 minutes or more. How long did you mash? If just for an hour, yes, that will have some effect. If longer, probably not so much.

Who usually mills your grains? Who milled the grains this time? Any changes in mill gap settings?

yeah, I mashed it for only 60 mins as always with this low temperature. And I milled the grains myself as always too. Just this time I got the malt from a friend rather than from a shop I normally got the malts.

 

[Miles_1111]

As a side question, did you perform a starch test after the mash to check the conversion was complete?

No, I did not. In fact, never did that before. But this rings a bell, I need to add this test into my brewing process. Thanks bro.

 

[Miles_1111]

You left out a couple critical pieces of information. Was the crush of the grain identical. The first 3 causes of low mash efficiency are:
The crush, the crush, the crush. All other factors are less.
The second piece of info missing is the mash period. While most often the mash period is 60 minutes, that period is related to the crush and the mash temperature. With my very finely crushed grains, my mash period for full conversion and extraction of flavors at 156F can be as short as 20 minutes. Milling coarser, I might need 60 or more to get full conversion. MaSshing cooler will take longer too. Alpha amylase works fast, beta much slower.

Since the mash period depends on the crush and the temperature. I guess the safest way is to use starch test to see if the conversation is complete. Agree?

 

[Miles_1111]

Another piece info is that this time I used Pilsner (2 Row) Bel, while before I always used Barley (2 Row) US. Could this be a cause too?

 

[RM-MN]

The starch test will be an indicator but it can be a false indicator as often as true. You need the grain particles to see if you got full conversion but often there will be a tiny residual starch and that will trigger the blue color with the iodine. You may be very near complete conversion or a long way from it and no way to know why the iodine turned blue.

 

[Miles_1111]

The starch test will be an indicator but it can be a false indicator as often as true. You need the grain particles to see if you got full conversion but often there will be a tiny residual starch and that will trigger the blue color with the iodine. You may be very near complete conversion or a long way from it and no way to know why the iodine turned blue.

Guess next time if the temperature is still this low again, I will just extend the period to 90 mins then.

 

[balrog]

Rather than starch test, I wonder if doing Kaiser's calculation for mash efficiency (use grist mass and mash water used, read refractometer and calc using this) is better? When I had "std" crush in a batch recently, this showed me after 60m to be at 65% when normally (very fine BIAB grind) i'd be in the 90's (again this is just mash efficiency)

 

[CJ-3]

Another piece info is that this time I used Pilsner (2 Row) Bel, while before I always used Barley (2 Row) US. Could this be a cause too?

To be honest I have no scientific data to back up what I am about to say

I have noticed when I use Pilsner malt my mash takes 75-90 minutes.

 

[eetu]

I used traditional floor malted pilsner once and had hard time getting good efficiency. Don't know for a fact but maybe it needs longer mash or something like traditional decoction to get good efficiency.

 

[RM-MN]

Guess next time if the temperature is still this low again, I will just extend the period to 90 mins then.

90 minutes may still be to little. It would be better to note how you got such a low mash temperature and avoid it in the future.

 

[mabrungard]

The final mashing step temperature definitely has an effect on efficiency. I have a RIMS and always conduct a mashout step at 168F. I always see about 1 to 2 Brix increase in the wort strength from that step. The magnitude of the increase is dependent on what the previous step temperature was. A low previous temp means that the mashout step is going to produce a larger increase in wort gravity.

 

[eric19312]

You did not mention water treatment. A 109% Pilsner beer might need acid treatment to get ph down.

You did not mention mash thickness or sparse technique. Normally I get higher efficiency on smaller grain bills. But if you did full water volume BIAB mash you might of had a very thin mash which could impact.

That said Temp is surely part of issue. I recently did a mostly 2 row batch at 148F and followed conversion with bruKaiser method. 3 hours was still not 100% converted.

 

[Lefou]

I used traditional floor malted pilsner once and had hard time getting good efficiency. Don't know for a fact but maybe it needs longer mash or something like traditional decoction to get good efficiency.

Depending on the style I will add malted wheat and grind it well. Wheat increases diastatic potential. Adding extra amylase powder to the mash helps. I tend to use Belgian Pilsner for brewing and have noticed issues with my efficiency numbers.
Let's be nerdy and reference something called the Kolbach Index, which measures the solubility of malted grain. It's "supposed" to give you an idea of your grain's enzymatic level, but how useful or accurate it is gives me doubts.

 

[dmtaylor]

Every malt sold these days is over-modified. Even the floor malted ones have high Kolbach indices. Decoction is never needed unless you know a maltster and personally beg them to do a crappy job malting for you so you can decoct. I do not know of such a maltster.

 

[Miles_1111]

You did not mention water treatment. A 109% Pilsner beer might need acid treatment to get ph down.

You did not mention mash thickness or sparse technique. Normally I get higher efficiency on smaller grain bills. But if you did full water volume BIAB mash you might of had a very thin mash which could impact.

That said Temp is surely part of issue. I recently did a mostly 2 row batch at 148F and followed conversion with bruKaiser method. 3 hours was still not 100% converted.

I used the purified water and took an example of the wort before boiling, the PH is between 5.1 and 5.4, which i suppose is fine. Well, I did know how thick is the mash, did not realize need to do that measurement..