Mash Efficiency Effect of Grain Past "Best By" Date on Sack

[micraftbeer]

I have a sack of Weyermann Munich I malt. I hit a gap in my brew schedule and I've got a bunch of that grain left now (11/15/2023) even though it has a Best By date on the sack of 1/13/2023. I've got a brewing experiment I plan to do, to try to quantify the effect of a process variable in some new equipment I'm evaluating. My plan is to use 100% of my expired Munich malt and compare the mash efficiency.

I've reached out to Weyermann as well, but looking for any experience/feedback on using grains (uncrushed) ~1 year past their best by date?

I'm wondering if it will just have an impact on taste (which doesn't matter for this experiment) or impact on conversion efficiency (which will matter- to some degree).

 

[day_trippr]

iirc, Weyermann's "best by date" is 18 months from bagging. That's aggressive imo - I'm actually using up Weyermann Pilsner that was bought in November of 2020 with a Best By Date of April 28 2022. Most of that malt waited in the bags for over 2 years while I dealt with a spine injury, subsequent surgery and recovery, and I didn't start brewing again until late this January when the surgeon finally released the chains

The malt still smells and tastes great as always. So does the Golden Promise and the Briess Brewers Malt from the same buy. I think unmilled malt still in the original bags will be quite viable for a few years from bagging...

Cheers!

 

[hotbeer]

I don't think it'll be enough difference in conversion efficiency to matter much to your OG. Whatever it is will be easy enough to adjust subsequent batches with it to achieve more closer the OG you wish. Similar for FG if it does in fact seem to alter what you are getting.

Changing the amounts used will handle the OG issue easily enough. Changing the mash temps and time can solve both OG and FG issues. If, and to me it's still a big if whether you'll see much difference, assuming the malt still taste, smells and has a good crunch when you bite into it.

 

[dustinstriplin]

Echoing what others have said. The timeline you shared isn't really that long.

It is worth calling out that Munich I does have lower diastatic power than other base malts. Adding a couple handfuls of Pilsner in there or adding some enzymes directly will give some extra insurance. I'd opt for the pilsner because it's simpler.

 

[sibelman]

One potential concern: the moisture content may have increased, making the malt "slack" and possibly affecting the crush (which could influence efficiency).

 

[VikeMan]

One potential concern: the moisture content may have increased, making the malt "slack" and possibly affecting the crush (which could influence efficiency).

Yep. And it's not just the crush. If the malt has gone slack, the extra moisture would in and of itself decrease (apparent) efficiency, as there will be less starches per pound of malt. (This assumes that the extra moisture (and decreased yield) isn't accounted for in the recipe and grain weight isn't increased accordingly.)

@micraftbeer are you planning to measure old and new malt wort gravities side by side (with equal, non-adjusted) weights of malt? I think the result could be interetsting.

 

[micraftbeer]

@VikeMan in this case I wasn't doing a comparison of out of date vs in date malt. I was doing an experiment on a Blichmann BrewEasy Compact to see if sparge vs. no-sparge had the same effect on efficiency as I've seen on other All-In-One units with a more conventional mash basket (BrewEasy compact has a conical shape basket with a lot of liquid volume outside the mash basket, vs. other AIO with a cylindrical basket).

Since I was just trying to get this comparison data in a less time-intensive manner, I just did the mash, and didn't go on to do a full brew batch. I know, for-shame, dumping that wort... It was a good way to make use of a large amount of out-of-date Munich malt that I wouldn't trust in my other recipes anyway. I just didn't want the out-of-datedness skew my efficiency numbers of sparge vs. no-sparge.

So this doesn't compare in-date vs. out-of-date malt, and it's 100% Munich which may be lower on the conversion efficiency anyway. But below are those numbers just to not leave anyone hanging...

No-Sparge: 2.56* qt/lb, no sparge water, 69.7% Mash Efficiency
Sparge: 2.12* qt/lb, 6.9 gal mash water, 1.3 gal of sparge water, 73.7% Mash Efficiency

* Note that these mash thickness numbers are a bit convoluted. The numbers here are simply the volume of mash water into the vessel divided by the lbs. of grain into the basket. But again, due to uniqueness of the BrewEasy Compact cone basket, you have a LOT of water outside the basket. I did some measurements/geometry, and the Sparge batch above was the equivalent of about 1.1 qt/lb inside the basket. It was as thick as I could make it.

 

[doug293cz]

@VikeMan in this case I wasn't doing a comparison of out of date vs in date malt. I was doing an experiment on a Blichmann BrewEasy Compact to see if sparge vs. no-sparge had the same effect on efficiency as I've seen on other All-In-One units with a more conventional mash basket (BrewEasy compact has a conical shape basket with a lot of liquid volume outside the mash basket, vs. other AIO with a cylindrical basket).

Since I was just trying to get this comparison data in a less time-intensive manner, I just did the mash, and didn't go on to do a full brew batch. I know, for-shame, dumping that wort... It was a good way to make use of a large amount of out-of-date Munich malt that I wouldn't trust in my other recipes anyway. I just didn't want the out-of-datedness skew my efficiency numbers of sparge vs. no-sparge.

So this doesn't compare in-date vs. out-of-date malt, and it's 100% Munich which may be lower on the conversion efficiency anyway. But below are those numbers just to not leave anyone hanging...

No-Sparge: 2.56* qt/lb, no sparge water, 69.7% Mash Efficiency
Sparge: 2.12* qt/lb, 6.9 gal mash water, 1.3 gal of sparge water, 73.7% Mash Efficiency

* Note that these mash thickness numbers are a bit convoluted. The numbers here are simply the volume of mash water into the vessel divided by the lbs. of grain into the basket. But again, due to uniqueness of the BrewEasy Compact cone basket, you have a LOT of water outside the basket. I did some measurements/geometry, and the Sparge batch above was the equivalent of about 1.1 qt/lb inside the basket. It was as thick as I could make it.

What you are comparing here is lauter efficiency (that's what is affected by sparging.) Conversion efficiency shouldn't be significantly different, unless you did a short mash time, and the faster rate of conversion of thinner mashes came into play. Did you by any chance measure the SG of the wort at the end of mash (prior to sparging) for the sparged batch? If so, we can calculate the conversion efficiency of each batch.

Mash efficiency = conversion efficiency * lauter efficiency, so for your experiment, you want to calculate mash efficiency and conversion efficiency and then use those to calculate lauter efficiency (= mash efficiency / conversion efficiency.)

Brew on

 

[micraftbeer]

Dang, I did not.