Efficiency ceiling?

[GForce]

First post ever!

I've been brewing all grain for about a year now with pretty good results. I just tried to make my first Imperial Stout, and came up woefully short on the OG. I was following a recipe I found in Zymurgy. According to BeerSmith (which I trust unquestioningly), the amount of grain in the recipe and their reported OG, they're expecting a 72% efficiency (17.9 lbs of grain, 1.092 OG). I batch sparge, btw. I was expecting to get at least 60% efficiency, but what I wound up with was 53% (1.067 OG). I doubt I can fit 10 more pounds of grain in my mash tun in order to get to the right gravity. Are there any other options other than using malt extract?

 

[KayaBrew]

I've never brewed a beer with 17+ pounds of grain, but my guess as to your low efficiency would be the batch sparge. It seems like it would be difficult to rinse that much grain in a batch sparge. Did you do a single batch sparge or a double? My eff. usually runs from 70%-80%, and I do a single batch sparge. I stir the hell out of the mash, then I let the grain bed set up for about 10 minutes before I vorlauf.

Welcome to HBT, by the way!

 

[Dan]

My eff. usually runs from 70%-80%, and I do a single batch sparge. I stir the hell out of the mash, then I let the grain bed set up for about 10 minutes before I vorlauf.

Welcome to HBT, by the way!

Do you drain your mash tun before you sparge or just add sparge water to the mash, vorlauf and drain the entire thing? Could it be that simple to get 70-80 percent? Please say yes!

 

[GForce]

I'm reading a little bit about efficiency now, and I'm coming across some things about lautering flow rate. Apparently if you drain slower you get better efficiency? Does anybody know if that also applies when you're batch sparging?

 

[cjd3]

My last 10 gallon batch yielded a really high efficiency, higher than normal. I tried to maintain a sparge at 168 that took 55 minutes, and I still had 1.020 sg in the remnant runoff. This was also with 27# of grain.

 

[ajf]

I'm reading a little bit about efficiency now, and I'm coming across some things about lautering flow rate. Apparently if you drain slower you get better efficiency? Does anybody know if that also applies when you're batch sparging?

The longer sparge only applies to fly sparging. With a batch sparge, the gravity of each batch of runnings is determined by how well you stir before vorlaufing and draining and the flow rate will not increase your efficiency.
17 lbs grain for a 5g batch is a lot, and all other things remaining equal, your efficiency will decrease as the grain bill increases. If you have equipment suitable for fly sparging, you may be able to get higher efficiency by doing a very slow sparge, but without the right equipment and a lot of patience, fly sparging will probably reduce your efficiency.

-a.

 

[JuanMoore]

What he said ^^^

IMO the biggest contributors for efficiency when batch sparging are the crush and how well the grist is stirred with each sparge addition. You could probably improve your efficiency some with a finer crush, and possibly stirring more thoroughly. For really big beers you could also do an additional sparge to collect more wort, and then boil longer.

 

[asterix404]

I have to say though, I do batch sparge very slowly and I lauter very slowly and the biggest reason I do that is because the grain sets up so nicely that way and I never get a stuck sparge.

You need to crush you own grain. You should be able to hit between 70 and 75%, but really not much more than that. You might want to considder dropping some of the grain and doing DME for imps, that is what I like to do... but I don't really brew many imps anymore.

 

[KayaBrew]

Do you drain your mash tun before you sparge or just add sparge water to the mash, vorlauf and drain the entire thing? Could it be that simple to get 70-80 percent? Please say yes!

I vorlauf until the wort runs clear, then I collect my first runnings. I drain the mash tun ultra-slow. It takes about 10 minutes to collect the first runnings. Then I add my sparge water (usually about 3.5-4 gallons), stir for a couple minutes, then let it rest for 10.

I also like to do a very thin mash. I usually go 1.5 to 1.75 quarts per pound of grain. The traditional wisdom is a ratio of 1.25 qt. per pound of grain.

 

[asterix404]

1.5-2qt per pound is fine with a decoction mash, you really don't want to get much higher than 1.5qt/pound with a single infusion due to the drop in enzyme activity. It is possible with the awesome base malts available this is less of a problem however, but if you use Munich malt as a base, you really want to stick to between 1.25 and 1.5qt/pound. I always do equal parts strike and sparge. The trick with sparge is that every drop that you put in you can get back because the grain is wet already.

Vorlauf sounds fine, I generally do a gallon and it sort of runs clear... sort of doesn't, it's hard to tell until it hits the end.

BTW, I should say, you should hit between 70-75% with an imperial, you can hit upwards of 85% for a single infusion mash depending on crush for a normal beer. That is very important to state, for a normal beer. You do get dinged with the imperial, which is why I like to add DME.

 

[Dan]

I vorlauf until the wort runs clear, then I collect my first runnings. I drain the mash tun ultra-slow. It takes about 10 minutes to collect the first runnings. Then I add my sparge water (usually about 3.5-4 gallons), stir for a couple minutes, then let it rest for 10.

I also like to do a very thin mash. I usually go 1.5 to 1.75 quarts per pound of grain. The traditional wisdom is a ratio of 1.25 qt. per pound of grain.

Thanks, maybe I'll go a little thinner on the mash. I have my brew software set up for 1.25 quarts per pound.