Low efficiency on an IPA

[inthesound]

Brief background, all-grain, 5 gallon batches, fly sparge. Typically achieve around 75% (anywhere from 72-84). The last two batches of a specific IPA recipe I brewed, I've had issues with poor efficiency. I think I know what my problem what today, so maybe you'll all confirm it.

8.75# two-row
.75# munich
.5# victory
.5# crystal 40L
.5# mild ale malt

So typically I do a 30 minute protein 122˚rest for 30 minutes, then I do the sacch rest at 155˚ for 60 minutes. This is the way my buddy and I have brewed for a couple months now, and it has provided consistency (and some comfort) while we really start crafting and tweaking our beers. The difference this time, is that I used a target mash temp of 152˚. So typically, I heat a quart of water per pound of grain to 135˚ for the protein rest, mash-in, wait thirty minutes, then use this equation (desired temp-current temp)*(.2*#'s of grain+mash-in water in quarts)/(210-155) (boiling water temp-desired temp). For this recipe, it gave me a volume of 6.8...quarts of boiling water to be added.

So I boiled about 1.75 gallons of water, and added it at the appropriate time, and my target temp was a few point shy, so I boiled up another gallon of water or so, added it and got to my 152˚. I typically check the temp and stir every 20 minutes, and I was dropping temp at each time, so I added more water to bump the temp back up (only as much as I needed), and by the end of my mash, I had a rather thin mash. I sparged slow as usual (about 6 gallons in an hour), and made sure to add some sparge water as I drained to kick the temp up on the sparge.

Anyhow, after it was all said and done, and an hour boil later, I ended up 7 points shy on my gravity reading. I should've hit 1.061 (@75% eff), and I hit 1.054.

Now, what I'm assuming happened is I didn't get my typical conversion due to the lower target sacch rest temp during my mash. Had I entered the equation as I typically do, I would have needed to add about 2 gallons of boiling water instead of 1.75-ish. This probably would've gotten me to 155˚ for that first 20 minutes, and then it would've slipped down to around 151-152 as it typically does.

Blarg. I think I know what I did, but if there are any glaring issues to you all, please let me know.

Thanks,

.chris

 

[dawgmatic]

I don't think a slightly lower sacch rest temp would result in lower efficiency. I would think it would have to do with your mash, and potentially you not using enough water to sparge, or even the sacch rest not being long enough to achieve full conversion

If you want your mash to hold temp better you should probably leave it sealed up longer. Mine will usually only drop 2 degrees at the most after an hour

 

[TrubHead]

Brief background, all-grain, 5 gallon batches, fly sparge. Typically achieve around 75% (anywhere from 72-84). The last two batches of a specific IPA recipe I brewed, I've had issues with poor efficiency. I think I know what my problem what today, so maybe you'll all confirm it.

8.75# two-row
.75# munich
.5# victory
.5# crystal 40L
.5# mild ale malt

So typically I do a 30 minute protein 122˚rest for 30 minutes, then I do the sacch rest at 155˚ for 60 minutes. This is the way my buddy and I have brewed for a couple months now, and it has provided consistency (and some comfort) while we really start crafting and tweaking our beers. The difference this time, is that I used a target mash temp of 152˚. So typically, I heat a quart of water per pound of grain to 135˚ for the protein rest, mash-in, wait thirty minutes, then use this equation (desired temp-current temp)*(.2*#'s of grain+mash-in water in quarts)/(210-155) (boiling water temp-desired temp). For this recipe, it gave me a volume of 6.8...quarts of boiling water to be added.

So I boiled about 1.75 gallons of water, and added it at the appropriate time, and my target temp was a few point shy, so I boiled up another gallon of water or so, added it and got to my 152˚. I typically check the temp and stir every 20 minutes, and I was dropping temp at each time, so I added more water to bump the temp back up (only as much as I needed), and by the end of my mash, I had a rather thin mash. I sparged slow as usual (about 6 gallons in an hour), and made sure to add some sparge water as I drained to kick the temp up on the sparge.

Anyhow, after it was all said and done, and an hour boil later, I ended up 7 points shy on my gravity reading. I should've hit 1.061 (@75% eff), and I hit 1.054.

Now, what I'm assuming happened is I didn't get my typical conversion due to the lower target sacch rest temp during my mash. Had I entered the equation as I typically do, I would have needed to add about 2 gallons of boiling water instead of 1.75-ish. This probably would've gotten me to 155˚ for that first 20 minutes, and then it would've slipped down to around 151-152 as it typically does.

Blarg. I think I know what I did, but if there are any glaring issues to you all, please let me know.

Thanks,

.chris

How much water in the mash tun at the end of the sacch rest? I'm a little foggy today so apologies if it's obviously stated.

 

[dawgmatic]

How much water in the mash tun at the end of the sacch rest? I'm a little foggy today so apologies if it's obviously stated.

If I read correctly he would have been at 5.5 gallons at the end of the mash, plus he added some of his sparge water while draining to keep the temp up. So prob closer to 6

 

[TrubHead]

If I read correctly he would have been at 5.5 gallons at the end of the mash, plus he added some of his sparge water while draining to keep the temp up. So prob closer to 6

For 11 lbs of grain then much more than 16 qts/4 gals would probably be too much water for the enzymes to do their work.

 

[billl]

"For 11 lbs of grain then much more than 16 qts/4 gals would probably be too much water for the enzymes to do their work."

Huh? That definitely isn't true. Lots of people mash above 1.5 qt/lb and have no problems at all.

If you are getting inconsistent efficiency numbers and your efficiency drops at lower mash temps, then you probably are having some conversion issues. The enzymes work slower at lower temps, so if you are just marginal at 155 degrees, you could easily drop from 100% conversion down to 90% at a lower temp.

You might just try a slightly longer mash next time to compensate for the lower temps. If that doesn't work, you can re-evaluated your crush and water chemistry to help speed things along.

 

[TrubHead]

"For 11 lbs of grain then much more than 16 qts/4 gals would probably be too much water for the enzymes to do their work."

Huh? That definitely isn't true. Lots of people mash above 1.5 qt/lb and have no problems at all.

If you are getting inconsistent efficiency numbers and your efficiency drops at lower mash temps, then you probably are having some conversion issues. The enzymes work slower at lower temps, so if you are just marginal at 155 degrees, you could easily drop from 100% conversion down to 90% at a lower temp.

You might just try a slightly longer mash next time to compensate for the lower temps. If that doesn't work, you can re-evaluated your crush and water chemistry to help speed things along.

I'm not one of the fortunate when going much above 1.5 qt/lb. So I stick with 1.5 qt/lb or less and get upper 80s extract efficiency.

 

[billl]

"I'm not one of the fortunate when going much above 1.5 qt/lb. So I stick with 1.5 qt/lb or less and get upper 80s extract efficiency."

Glad you found something that works for you, but that certainly isn't a rule. Denny Conn is promoting a 1.75 mash as working the best for him. Obviously, a lot of people stick with the 1.25 guideline too. Like most other things in brewing, it appears that a wide range of ratios can all work to make good beer.

 

[TrubHead]

"I'm not one of the fortunate when going much above 1.5 qt/lb. So I stick with 1.5 qt/lb or less and get upper 80s extract efficiency."

Glad you found something that works for you, but that certainly isn't a rule. Denny Conn is promoting a 1.75 mash as working the best for him. Obviously, a lot of people stick with the 1.25 guideline too. Like most other things in brewing, it appears that a wide range of ratios can all work to make good beer.

I'm glad too. Denny gave me some mash tips a while back that helped push the efficiency numbers up. I didn't read about the 1.75 ratio. Tried higher ratio (2 qt/lb) but conversion plummeted and ended up with a "light" beer.

 

[inthesound]

Yeah, I think I had just under 5 gallons of water in there before I ever hit my target temp. I'm guessing I added around 2 more gallons over the course of an hour to maintain temp. Possibly more. By the time I sparged, my blue rectangular cooler was only a couple inches away from being full. Perhaps adding any water during the sparge was a mistake, though I wanted to try and get the mash temp up to 168-170 for sparging.

We crush our own grains, and again, typically get anything ranging from 72-84% efficiency. I am interested in double milling which many seem to do on here.

I think I learned my lesson here. If I'm going to start monkeying around with the specifics of our brewing, I should have done an iodine test to make sure my conversion was complete.

 

[billl]

"I think I learned my lesson here. If I'm going to start monkeying around with the specifics of our brewing, I should have done an iodine test to make sure my conversion was complete."

Iodine tests do not show whether you have full conversion. All they indicate is if there is starch in solution that hasn't been converted yet. If the starch is still locked in the grain, iodine will not pick that up.

 

[winvarin]

I'm glad too. Denny gave me some mash tips a while back that helped push the efficiency numbers up. I didn't read about the 1.75 ratio. Tried higher ratio (2 qt/lb) but conversion plummeted and ended up with a "light" beer.

It has been my experience that the thinner I mash, the more I have to recirculate or stir during the mash. Otherwise I run into efficiency issues. I found a reasonable sounding idea on that in another thread. The poster speculated that diluting the mash by going thinner also diluted the concentration of enzymes. This means that agitation through stirring o recirculating better allows the starch to come in contact with the enzymes

 

[TrubHead]

It has been my experience that the thinner I mash, the more I have to recirculate or stir during the mash. Otherwise I run into efficiency issues. I found a reasonable sounding idea on that in another thread. The poster speculated that diluting the mash by going thinner also diluted the concentration of enzymes. This means that agitation through stirring o recirculating better allows the starch to come in contact with the enzymes

One of Denny's tips was to thoroughly stir once before sacch rest and no more during the remaining 60 min. This reduced heat loss and did not degrade efficiency. I used to stir every 15 minutes and even that amount of stirring didn't help the 2 qt/lb dilution of enzymes.