Very low efficiency.

[oregonNate]

I did a 5 gallon batch on Saturday and only got 48% efficiency! My pre-boil SG was only 1.038 (expecting 1.05) with the following grain bill:

6lbs Pale Ale Malt (2-row)
2lbs Lager Malt (6-row)
2lbs Wheat Malt
1.3lbs CaraPils
4lbs Pumpkin
.75lbs rice hulls

I mashed in with 170° water in a pre-heated cooler, 1.1qts per pound and it leveled out right at 150°. Let it sit for an hour and it only dropped to 148°.

I batch sparged so I wasn't expecting super high efficiency, but I usually get 65-70%. Anyway..I ran off the first batch and only got 2 gallons at 1.065, can't figure out where the other 2.5gallons went,..but wow...they didn't come out. Second batch I added another 4 gallons and got 4 gallons out, but at 1.024. Is this what people call a stuck mash?

Ended up adding 2lbs of Jaggery (unrefined Indian sugar) so my OG was 1.054 so I think it will turn out ok....

Any ideas on why this happened? One thought I had was that my grain wasn't milled enough. I found a few un-cracked grains in the 2-row. The other idea was that the pumpkin mucked things up. Perhaps I needed more rice hulls.

 

[Steve973]

How thick was your mash? It sounds like something absorbed a bunch of your sparge water. As far as the rice hulls go - they're just a filtering agent, so if the wort ran clear after a decent amount of time, then I don't think that was the problem. The second thing is that your mash temperature might have been a tad low. Did you test for conversion before you sparged? You might have needed another thirty minutes or so. Also, did you have a particular reason for the 6-row rather than just using all 2-row? And what was your post-boil gravity?

 

[oregonNate]

Mash wasn't very thick 1.1qts/lb. I could stir it easily and the temperature readiings were even accross the mashtun.

6-row has a higher diastic(sp?) power. (More enzymes to help convert pumpkin.)

Mash temp was 150°, which I thought was a good middle value... I've mashed as low as 145° in a previous batch and had good conversion. I've never tested for conversion... I should learn how. Is that something to do with iodine strips or something?

Post boil, (including 2lbs sugar added) OG was 1.054.

 

[Steve973]

Yes, you can test to see if starches remain by using iodine. If I understand correctly, the point of the pumpkin is not to convert the starches to sugars, since you don't get much sugar from the pumpkin anyway. Pumpkin is notorious for clogging up a mash, as well. Next time, try adding the pumpkin to the boil, since that's the best place to extract color and flavor. And to maximize *that* portion, you could consider spreading the pumpkin on cookie sheets (thinly) and baking it in the oven to carmelize the pumpkin.

 

[Steve973]

I should say that I'm quite out of practice, so other people might be able to point you in a better direction than I can. It has been about 1.75 years since i've brewed anything, sadly. That's about to change though!

 

[oregonNate]

Yes, you can test to see if starches remain by using iodine. If I understand correctly, the point of the pumpkin is not to convert the starches to sugars, since you don't get much sugar from the pumpkin anyway. Pumpkin is notorious for clogging up a mash, as well. Next time, try adding the pumpkin to the boil, since that's the best place to extract color and flavor. And to maximize *that* portion, you could consider spreading the pumpkin on cookie sheets (thinly) and baking it in the oven to carmelize the pumpkin.

I did spread it out and bake it for an hour at 350° It was nice and carmelized...and made my whole house smell wonderful.

I've heard mixed reviews on adding it to the boil vs. mash...perhaps I will try that for my 2006, if I make this a tradition.

 

[oregonNate]

I should say that I'm quite out of practice, so other people might be able to point you in a better direction than I can. It has been about 1.75 years since i've brewed anything, sadly. That's about to change though!

Good luck on the first batch back. It is always fun to re-discover lapsed hobbies.

 

[oregonNate]

I just brewed another batch and ended up with 63% efficiency... not that great. Here are the things I did different:

1. My grain was crushed better. Not too thin, but fully crushed.
2. No pumpkin, very little wheat malts.
3. 1.2qts/lb mash in
4. Higher mash temp: 154.

I got 7 gallons of 1.065 wort out of 20lbs of grain. First runnings were at 1.098, second runnings 1.045ish and third runnings 1.03.

Looks like my system absorbs 1.7 gallons of water per 10lbs of grain. Is this high? Should I be able to extract more water out of it?

After 90 minutes of boiling it ended up going into the fermenter at 1.084.

I may have to stop this batch sparging and try something else to get better efficiency. I would be happy with 65-70%.

Any comments and/or suggestions?

 

[Sir Sudster]

My calculations through ProMash says with 11lbs of grain you will get 2.75 gallon absorbtion by the grain.

It sounds like you have a PH issue in your mash . Start checking your PH especially if you have high carbonates in your water. Hard water will also effect your mash efficiency.

I started using a product called 5.2 PH stabilizer and it has help me go from 68% to 85% efficiency.

If you really want to do it right get a water analysis specifically for minerals and salts.

 

[SwAMi75]

I just brewed another batch and ended up with 63% efficiency... not that great. Here are the things I did different:

1. My grain was crushed better. Not too thin, but fully crushed.
2. No pumpkin, very little wheat malts.
3. 1.2qts/lb mash in
4. Higher mash temp: 154.

I got 7 gallons of 1.065 wort out of 20lbs of grain. First runnings were at 1.098, second runnings 1.045ish and third runnings 1.03.

Looks like my system absorbs 1.7 gallons of water per 10lbs of grain. Is this high? Should I be able to extract more water out of it?

After 90 minutes of boiling it ended up going into the fermenter at 1.084.

I may have to stop this batch sparging and try something else to get better efficiency. I would be happy with 65-70%.

Any comments and/or suggestions?

Yeah, I think fly sparging will definitely help you. It takes more time, but it should bring up your efficiency some. Also, try doing a mash out: bring your mash temp up to around sparge temp before you begin sparging.

And as Sudster mentioned, check out your mash pH. You can test it and adjust, or use a pH stabilizer. I did the latter, because I'm lazy.

I started doing all of the above, and saw a dramatic increase in my efficiency. I started out at about 65%....I did a batch with all the above, and my gravity was WAY over what I wanted. I was aiming for 1.055, and wound up at 1.066. I calculated the batch assuming 70% efficiency, and wound up with about 85%.