gravity

[michaelpeach76]

I just brewed a brown ale today. This batch was the first time I mashed out and batch sparged...where as in the past I didn't mash out and I would fly sparge. I changed my technique because I wasn't the original gravity that I wanted. The I brewed to day was supposed to have a OG of 1.061 and instead it had an OG of 1.050. Given that I tried something new and still came out low.....what am I doing wrong, or what am I not doing?

 

[kylevester]

Batch sparging gives lower efficiency compared to fly sparging, so you have to compensate for that.

Since I switched to all-grain, I've only done either straight fly sparging or a hybrid approach I came up with on my own. The hybrid was to drain the mash tun, add a first batch sparge and then fly sparge off that. I get more consistency with straight fly sparging, so I do that exclusively now.

The most common cause of low efficiency is your crush quality. A poor crush leads to less conversion because there's less surface area and/or the starches don't get freed from the husks and pulverized as well.

If your crush is good, then you could have dough balls leading to low efficiency. Since I started adding the water to the mash tun and then adding the grains with a scoop and while stirring, I get very consistent numbers except for real high gravity batches (1.100 up).

Explore the All-Grain forum, even experienced brewers can glean important info from there. Also, more detail will help folks diagnose. Your temps, age of grain, liquor to grist ratio, etc. can help us winnow down to your problem. You may want to repost in the All-Grain forum.

 

[michaelpeach76]

Hybrid sparge would help...? Or if the main culprit being inefficiently milled grain...would you then suggest throw the milled grain back for a second run through...basically milling it twice?

 

[duboman]

Hybrid sparge would help...? Or if the main culprit being inefficiently milled grain...would you then suggest throw the milled grain back for a second run through...basically milling it twice?

There are a lot of variables associated with all grain brewing in relationship to hitting your gravities and efficiency.

Grain bill
Mash temps
Sparging
Milling of grain-crush
Hitting all your volumes

While many people say batch sparging will yield lower efficiency I can tell you that my efficiency is 82% consistently and I only batch sparge.

The first thing to look at first is grain crush and if someone else is milling your grain it's probably the first thing to check. Have them mill twice.

If you want answers to any of the other mentioned items we need your recipe, mash temps, process notes, volumes, etc in detail and we can help diagnose.

 

[michaelpeach76]

Hopefully this helps:
5 lbs 2 row
2 lbs crystal 80l
2 lbs vienna
2 lbs biscuit (belgian)
0.3 chocolate malt.
3.5 gallons strike water 162 degrees, Mashed at 153 degrees for 1 hour, mashed out adding 1.5 gallons, brought temp up to 168. Batch sparged with 3 gallons water at 170 degrees. boiled in kettle for an hour adding hop schedule.

 

[duboman]

Hopefully this helps:
5 lbs 2 row
2 lbs crystal 80l
2 lbs vienna
2 lbs biscuit (belgian)
0.3 chocolate malt.
3.5 gallons strike water 162 degrees, Mashed at 153 degrees for 1 hour, mashed out adding 1.5 gallons, brought temp up to 168. Batch sparged with 3 gallons water at 170 degrees. boiled in kettle for an hour adding hop schedule.

First, 2lbs of crystal is almost 20% of the recipe and IMO that's a lot and it is less fermentable.

As for water volume you use 8 gallons total, about 1.3 g lost to absorption should have given you about 6.7g in the pre boil, figure 1g boil off leaves you almost 5.75g in the primary.

Do these figures seem right and what you were shooting for? If not its also possible you left a lot of nice sugary wort in the MLT or you had too much volume and did not boil off enough to hit you OG.

Besides the crush there might be an issue with your volumes and not hitting you OG.

 

[michaelpeach76]

At the beginning of the Boil I had right about 6 gallons, and by the time I poured into the fermenter I had just barely under 5 gallons. Possible that maybe my temps weren't quite hot enough to thin out the wort enough to get everything?

 

[inhousebrew]

I'd start by running the grain through the mill twice to get a better crush.
Next, I'd start measuring everything to make sure you volumes are correct.

 

[Yooper]

Hopefully this helps:
5 lbs 2 row
2 lbs crystal 80l
2 lbs vienna
2 lbs biscuit (belgian)
0.3 chocolate malt.
3.5 gallons strike water 162 degrees, Mashed at 153 degrees for 1 hour, mashed out adding 1.5 gallons, brought temp up to 168. Batch sparged with 3 gallons water at 170 degrees. boiled in kettle for an hour adding hop schedule.

Your recipe is really terrible, I'm sorry to say. Way too much crystal 80L and way too much biscuit malt. That should not affect your efficiency though.

You used 1.25 quarts of water per pound of grain, so that's ok. I would have skipped the mash out (it's not necessary with batch sparging), but it doesn't hurt.

There are a couple of things that come to mind immediately when poor efficiency is noted. The first is crushed. Many homebrew stores give a poor crush. That is good for avoiding stuck mashes and sparges, but not great for high efficiency. The second thing is the amount of stirring when batch sparging. When you batch sparge, you have to stir like you mean it as that is what "knocks" the sugars off the grain and into the wort.

The thing to consider is that you didn't do too poorly with efficiency- you got around 62%. Often with crushed grains purchased from a homebrew store, 65-68% is reasonable. It would have been really tough to hit the goal of 1.061 that you wanted- that would have been 75% efficiency.

For the next batch, you could plan on hitting 65% and adjusting your grainbill accordingly. Simply stirring more thoroughly could fix that.

Can you tell us more about your procedure, with the stirring, draining, etc? Maybe we can pinpoint some tips for next time.

 

[duboman]

At the beginning of the Boil I had right about 6 gallons, and by the time I poured into the fermenter I had just barely under 5 gallons. Possible that maybe my temps weren't quite hot enough to thin out the wort enough to get everything?

In addition to what's already been Said If you started with 8 gallons and only got 6 into kettle then unless I'm not calculating or missing something there is some wort missing somewhere that would have helped with your efficiency as well as the stirring, etc that Yooper mentioned.