Efficiency problem / question

I just brewed a porter using a partial mash. BeerSmith tells me the OG should be 1.050 (assuming 75% efficiency), but I got a reading of 1.042 meaning my efficiency was a dismal 50%. What can be done to improve efficiency, or should I just expect this in future brews and compensate with more grain? I'm batch sparging, and I did a 60 minute rest at 154 degrees. The initial strike water was added at a ratio of 1.25 quarts per pound, and I used 5 lbs of grain. I did have to add an extra pint of boiling water at the beginning to get the temp up to 154 from 150, which I tried to quickly stir in.

What equipment are you using. What dead spaces do you have?
What temp did your mash finish at?
What was the recipe?
Was the 1042 preboil or at the fermenter?
What was the preboil SG?

orfy:

1. I'm using a 5 gallon Igloo cooler with a SS braid. There are 0.31 gallons of dead space.

2. Mash finished at 154 according to the thermometer - temp did not drop over the hour. It took several minutes to originally reach 154 as it first hit 150 (strike water was 166) and then I had to add the pint of 212 water. Mash was done with 1.25 quarts water / pound of grain, plus aforementioned one pint. Batch sparge was done in one round with 3 gallons and 1 3/4 cup of 168 water after draining the tun. I let the sparge water sit in the tun for 15 minutes before draining. Mash and sparge water was tap water treated with 1/2 campden tablet total (1/4 tablet each) to neutralize chloramine.

3. Recipe for 5.5 gallon batch:

Partial boil was used, boiling about 3 3/4 gallons.

4. 1.042 was in the fermenter after topping up to 5.5 gallons and stirring to mix water and wort, prior to pitching yeast. Water used for top-up was reverse-osmosis bottled water.

5. Did not measure preboil SG.

I'm a huge proponent of the mashout- raising the temp of the mash to around 168 deg., even if it means dumping the whole lot back into a kettle. I've done identical batches and get an increase of around six to eight gravity points when I do the mashout- this is with with ten pounds of grain, though, and it may not make as much of a difference with a partial mash.

Also, since sugar-laden whater is heavier than un-laden water and sinks to the bottom, a third of a gallon at the bottom of your tun seems like a lot- you may have a lot of unused sugars down there. I think this is a drawback to the braided filter... as it prevents a full siphon from the bottom (at least, if I'm understanding rightly).

Lastly, given your description, you may have some issues with your water chemistry.... those enzymes seem pretty sensitive (maybe a chemist or someone out there could verify this...).

Anyway, hope this is useful. -p

Your recipe calcs are correct and it seems that you did everything right except that I usually add some hot water at the end of the mash to raise the temp. If you added 2 more pounds of grain then it would have been in the expected range considering the efficiency. Other than that the one thing that will help is crushing the grain a bit finer if possible.

The last two posts mention a mash-out (raising the temperature before sparging).
This increased my efficiency by about 10% when I started doing it.
If you are batch sparging, the alternative to a mash-out is to increase the temperature of the sparge water so that your actual sparge temperature is 168 - 170 degrees.

-a.

The enzymes in the mash work most efficiently at a ph of around 5.1-5.3 so to get maximum efficiency adjust your mash ph to be within this range. This will also produce a beer with a lower chance of a chill haze. The effect can be significant.
Raising the temperature of the mash during mash out merely halts enzyme activity and has no effect on efficiency, except maybe to assist with liquifaction.

I didn't check pH, so that could be the issue. I don't know what the pH of my tap water is, I have not tested it. What is the best pH range for the water before it is added to the grain to get in the 5.1-5.3 range, and what chemicals work best for adjusting this?

Buy some PH 5.2 Buffer, add it to the mash, and forget about it. No need to measure the PH or add any additional chemicals. Used it today for the first time, and had by far my highest efficiency.

How much do you need to add, and does it contribute any off-flavors to the wort?

Buford said:

I didn't check pH, so that could be the issue. I don't know what the pH of my tap water is, I have not tested it. What is the best pH range for the water before it is added to the grain to get in the 5.1-5.3 range, and what chemicals work best for adjusting this?

Click to expand...

Don't concern yourself with the ph of your tap water (save that for later brews). Check the ph of your mash, this is the best and easiest adjustment you can make. Add calcium carbonate if the ph is to low (unlikely) or food grade phosphoric acid, lactic acid or gypsum if it is too high. It will probably take a couple of additions and measurements unless you get lucky first off but subsequent brews will require a similar amount, stir it straight into the grains. Go easy on the gypsum, this can add a harsh bitterness to beer. Phosphoric or lactic acid is your best bet. I can't speak for ph5.2, it's not readily available in the UK at a a reasonable price at least.

Actually, I just thought of one other reason the eff. might have been so low. I didn't stir the mash before draining, so a lot of sugar may have sunken to the bottom and gotten left behind.

I never stir the mash after douging in, it makes little or no difference.

Hey All
About time that I register with this fine forum.
I am mainly a extract brewer, hope to gear up
for all grain this year, this frorum should be a
great help for that.
Beer, Brewing, Sampling, Sharing, does it get any
better than that?

Welcome...don't procrastinate, it doesnt make it any easier but then again ag brewing is a snap

Buford said:

How much do you need to add, and does it contribute any off-flavors to the wort?

Click to expand...

No off-flavors. David_42 (who knows a lot more about brewing that I ever will) swears by the stuff.

Looks like I'll have to try that. I should probably try the exact same recipe again and only change one variable - adding 5.2 stabilizer - to see if that has any effect on my efficiency. 50% is just downright poor and verging on unacceptable, especially if I want to try an all-grain recipe around 1.050 in that 5 gallon cooler at some point.

I brewed the same recipe yesterday, using 5.2 pH stabilizer in the mash this time. I also tipped the mash tun when draining to try and get every bit of wort out of it that I could, and stirred before draining. One other difference is I added some of the sparge water (about one gallon) before draining the tun initially so that the first and second runnings would be about the same volume.

Drastic difference. Numbers came out this time to be around 72% efficiency. The boil had a little higher starting volume than last time due to collecting more wort as well, as I only used about 1 3/4 gallons to top up after the boil as opposed to the 2 1/2 gallons last time.

It'll be interesting comparing the two batches to see how much of a difference can be made by method when using the exact same grain and hop bill.