OG supposed to be 1.045, measured 1.025.....

[KRASHED]

Need help, no clue what happened, scaled a 5 gallon recipe to a 11 gallon (into the fermenter) and ended up with a gravity reading a full .020 lower than expected.

Probably my 20th batch, never had an issue scaling before.

Grain bill
9 lbs Pale Malt (2 Row) US (2.0 SRM) Grain 1 45.0 %
6 lbs Wheat malt (1.6 SRM) Grain 2 45.0 %
2 lbs flaked wheat (1.0 SRM) Grain 3 9.9 %
2.00 oz Saaz [4.20 %] - Boil 70.0 min Hop 4 14.7 IBUs
2.00 oz Coriander Seed (Boil 10.0 mins) Spice 5 -
2.00 oz Orange Peel, Bitter (Boil 10.0 mins) Spice 6 -
2.0 pkg Belgian Witbier (Wyeast Labs #3944) [124.21 ml]

Milling the grains wasn't an issue.... I don't know what went wrong.

I have dried malt extract, never had to use it before, would like to up the OG if possible. Also have an unlimited supply of maple syrup. Prefer to not over attenuate the beer though.

 

[adhomebrew10]

More details... What was mash temp and duration? I haven't plugged that grain bill into anything, but by the poundage I would expect an OG close to your prediction for 10 or so gallons. If your efficiency was that low it has to be something with the mash, or your reading was not accurate. I would test the hydrometer in distilled water and make sure it is accurate before adding any DME to the party.

 

[kh54s10]

Don't have time to put the recipe into Beersmith. But it is usually the crush. You say that isn't the issue. So it is either something to do with the mash, volumes, or a bad measurement.

 

[portguy]

That grain bill on 11 galon batch would have around 1042 OG...

 

[Qhrumphf]

How did you sparge? If you were fly sparging without rice hulls and that much wheat, it's possible that there was enough husk matter in enough pockets to cause channeling without actually sticking the mash. I'd sooner expect the mash to stick, but it's possible and would tank your efficiency.

 

[brandonlovesbeer]

Your post says nothing (that I could see) about how much wort you collected. I think collected to much or didn't let the over collection boil down enough.
Or
You tried to take a gravity reading with hot wort.

 

[oujens]

Have you used wheat malt before? Potentially milling could have contributed since the kernels are smaller. They need to be milled a little tighter to get a good crush. Your recipe uses a lot of wheat malt.

 

[KRASHED]

Sorry for the delay.

I have used wheat malt before without issue. But I;m starting to think that I should have gone a little tighter on the crush.

Pre-boil volume is 15gal, after postboil is about 12gal.

Single infusion batch sparge with no mash out. Saw that the wort was significantly lighter near the end of the sparge so I was confident I took out as much as possible of the fermentably sugars. 162 Fahrenheit was target and I kept it pretty consistent.

Mixed up the fermenter as often as I could to prevent pockets, seemed like an everyday normal mash for me.

All in all I wouldn't mind upping the ABV a bit to something at least reasonable. Any help would be appreciated

 

[doug293cz]

What was your actual OG in the fermenter? Did you measure hot wort with a hydrometer?

162 is on the (very) high side for a mash temp. If you crush was coarse, you could have denatured most of the enzymes before your mash was finished. This would impact your conversion efficiency, even more than just coarse crush alone.

Edit: Saw in title that OG was 1.025. Taking your volumes and SG measurements at face value, that puts you conversion efficiency at about 53 - 54%, and your mash efficiency at about 49 - 50%. Conversion efficiency should definitely be above 90%, and 95% or better is a reasonable target.

Brew on

 

[KRASHED]

Measured with cooled wort as I always do. Took multiple samples and made sure my hydrometer was calibrated correctly.

So what you're saying is that my temp was too high causing my conversion to crash out.

 

[balrog]

Beta Amylase denatures at 160, Alpha at 170. I've never actually seen a recipe call for a mash temp higher than 158 but I'm a noob, only 80 batches in.

Nice article here on temps, enzymes, etc.

 

[patthebrewer]

Just out of curiosity... what was your mash concentration for both your infusion, and then how much water did you use for your batch sparge. Had that prob before (I think everyone has) mine usually was related to looser concentration, resulting in to high temps for beta to be effective (as someone already mentioned). You can fix it by adding fermentables (i.e lme, honey, molasses, etc), and yeast.

 

[doug293cz]

Beta Amylase denatures at 160, Alpha at 170. I've never actually seen a recipe call for a mash temp higher than 158 but I'm a noob, only 80 batches in.

Nice article here on temps, enzymes, etc.

Actually, the amylase enzymes don't denature all of a sudden at a specific temperature. They degrade over time, with faster denaturing rates at higher temps. Beta denatures faster at lower temps than does alpha. They also work faster at higher temps, so we are playing a balancing game during mashing. We want them to work fast enough to complete the mash in a reasonable time, but the faster we make them go (the higher we heat the mash), the faster they "disappear." Turns out both beta and alpha are denaturing at typical mash (saccharification rest) temps, with beta denaturing faster at any given temp. Braukaiser republished a couple of charts showing how fast both beta and alpha denature at different temps.

The temps you give (160°F and 170°F) are about right for the temps at which you will denature essentially all of the beta and alpha (respectively) in about 10 minutes.

And, just to complicate things more, the lifetimes and activity vs. temp of the enzymes is not the whole story. Before the enzymes can start chopping up the starch into sugar, the starch needs to be gelatinized (basically the starch chains need to be surrounded by adsorbed water molecules, this is what happens when you cook rice or oatmeal) so that the enzymes can get at the bonds they need to break in the starch molecules. Gelatinization is slower than the enzyme action, so it is actually the rate of gelatinization that controls the overall rate of saccharification. Gelatinization starts at the surface of grain grits and works towards the centers. The larger the grits (coarser the crush) the longer gelatinization takes.

It's possible at higher mash temps that the enzymes can be denatured before gelatinization is complete, and if this happens you will have low conversion efficiency, no matter how long you mash. OP's mash temp was about 72°C, so beta will be gone in ~5 min, and alpha will be ~80% gone in less than 30 minutes. Extremely fine crushes can completely gelatinize in 5 min, but coarse crushes can take significantly longer.

Brew on

 

[balrog]

Wow. Schooled. Thanks. VERY interesting about the galatinization. Could be the efficiency problem if coarse crush plus high mash temp.