Low Efficiency

[rich]

Hey guys,

I brewed a stout last weekend, and by the time I was done sparging, the OG was 1.030. My target gravity was more like 1.060. Had to throw in 2 cups of DME and was pretty disappointed with having to do that. I am starting to see a pattern here, and would like to fix it, but am not completely sure the source of the problem. So I wanted to run a few things by everyone.

First, I live in a small apartment, does that have anything to do with it (just kidding). But seriously, I live in a small place, not much room for equipment, so I put together an all grain system that produces 2.5 to 3 gallon batches. I use my boil pot as my mash tun... I heat the water up at the right mark, put the grains in, then put the entire pot in the oven (on low heat) to hold the heat. It generally works. Sometimes a little better than others, but generally stable.

Then for my lauter tun, I use a five gallon food grade bucket with a spout hole drilled in the bottom, and a grain bag used for the false bottom. The grain bag fits perfectly into the bucket, with a fine screen at the bottom and a course mesh on the sides. Sometimes I raise the grainbag just a bit (with the grains in it) to give a little space at the bottom (although this time I didn't and the flow was fine). I connect my sparge arm, pour the grains into the lauter tun, wash out my boil pot, situate the pot under the lauter tun spout, and away it goes.

But again, I'm not sure what part of the system is causing the low efficiency. Is it the mash process or the sparge process? If it is the mash process, I could possibly buy a cooler and store it someplace (to get a more stable temperature hold). Again, sometimes the heat does fluctuate in the oven. Or is it a problem with the grain bag, and pouring the grains abruptly into the lauter tun? (I don't suspect it is, but can't be completely sure.)

Anyway, any feedback would be great. Happy Brewing.

Rich

:)

[Blkandrust]

I had a similar problem last week with my first all-grain batch.OG was 1.026!!I think it was either my crush or ph.Or maybe strike water was to hot.

[Grog]

Rich -

1.) How much grain did you use? - If the grain bed is too shallow that could be an issue.

2.) How fast was your run-off? - My experience : the faster I run off, the lower my efficeincy.

3.) Is doubling the grain bill feasable (or possible)?

-G-

[rich]

Grog and Blkandrust,

I could raise the amount of grains that I use, but the issue is that I was following the specifics from a recipe, and the target gravity for the grain amounts in this recipe called for an OG of 1.060, so I kind of was expecting that. In terms of run-off time, I took probably a little over an hour. I could have slowed the flow, but in the past I have conducted run-offs for up to 1.5 hours with not much different results.

Calculating the efficiency, then raising the grain amounts in the future could be an option, but the bottom line is that I will still have crappy efficiency, and will be using more grains than necessary.

Could it be the temperatures during run-off? Again, I use a plastic bucket as the lauter tun, which I'm sure allows for a lot of heat to escape. Probably not a factor at all. I just don't know.


Well, any additional trouble shooting would be appreciated.

[brewmonkey]

Did you recirculate prior to lautering? What was the temp of the tun during lauter? How about your sparge water (temp)?

pH would be the last thing to look at as even if it was off a bit it should not effect the gravity that much. My guess would be the speed at which you performed your lauter. To fast and you will be way low. Even with a small batch like 2.5 USG's you should take a good 20-30 minutes to do this step. It is slow and tedious work but very important in hitting the desired gravity.

[rich]

brewmonkey,

I recirculated, but fast (I litterally completely opened the spout twice and allowed two pints to fill up, then recirculated back in).

The mash temp was 151. I mashed out at 168, then poured entire batch into lauter tun. The sparge water temp was maintained at about 168-170. The lauter process itself lasted a little over an hour. But again, this is the third or fourth time I've fell short, and had to use DME, despite longer sparge sessions, and slower recirculation.

So from your feedback, I am gathering that the problem is in my sparge process, right? Should I scrap my idea to purchase a cooler and mash in that manner (as opposed to using the boil pot and maintaining the temp in the oven)?

I also didn't check the ph. Never have, but maybe I should start. But so long as I can start narrowing down the problemed areas, I'll have a stronger chance of figuring out what the hell is going on.

I am going to bottle this batch tomorrow. I hope at least it tastes good. Again, any feedback is appreciated.

[Grog]

Rich - Is this the first time you let the grain bag just sit on the bottom of the bucket?

My mini-mash system is very similar to your AG system. I use 5-6# of grain, I use the oven to maintain mash temp, I use an old bottling bucket as a LT, I use the grain bag, (I even recirulate nearly the same way.)

My efficiency went from mid 40%'s to low 60%'s by slowing my run-off from 10 min to 30 min (not your issue) and putting a colander on the bottom of the bucket. If you have been getting good results before this last batch and having the grain bag sitting on the bottom was the only difference...I think that may be the issue (but I don't have any reason other than personal experience to explain it).

-G-

[brewmonkey]

Originally posted by rich
brewmonkey,

I recirculated, but fast (I litterally completely opened the spout twice and allowed two pints to fill up, then recirculated back in).

The mash temp was 151. I mashed out at 168, then poured entire batch into lauter tun. The sparge water temp was maintained at about 168-170. The lauter process itself lasted a little over an hour. But again, this is the third or fourth time I've fell short, and had to use DME, despite longer sparge sessions, and slower recirculation.

So from your feedback, I am gathering that the problem is in my sparge process, right? Should I scrap my idea to purchase a cooler and mash in that manner (as opposed to using the boil pot and maintaining the temp in the oven)?

I also didn't check the ph. Never have, but maybe I should start. But so long as I can start narrowing down the problemed areas, I'll have a stronger chance of figuring out what the hell is going on.

I am going to bottle this batch tomorrow. I hope at least it tastes good. Again, any feedback is appreciated.

When you recirc it should be done slowly enough to not set the bed and until the wort runs clear. This will help get the grain bed set up to help filter the wort while still allowing for a decent run off. Going to fast during the recirc like you mentioned can set the bed to tight which will effect the efficiency of the system.

A tight bed would also lead me to believe that your bed was set. An hour for less then 3 gallons is to long. You should be closer to the 1/2 hour range IMHO.

Slow down the recirc, it should take about 10 minutes of slow going and you will see the wort running nice and clear. Once the wort is clear you can start the lauter.