11 replies to this topic

[consumptionjunction]

I'm planning on brewing my first high-gravity beer soon (OG = about 1.095) and have heard that efficiency tends to decrease with more grain. So far I've had really low efficiency (about 60%) until I began crushing my own grains (which let me hit about 85%). What is everyone's experience with high-gravity beers and efficiency? Is the lower efficiency because the water to grain ratio is typically lower in order to fit all the grains in a smaller mash-tun, making it harder for sugars to go into solution?EDIT: Oh yeah, I'm batch sparging.

Edited by consumptionjunction, 22 September 2009 - 04:47 AM.

[djinkc]

I was wondering about this earlier this year.My link

[consumptionjunction]

I was wondering about this earlier this year.My link

Thanks, I tried searching the forum but didn't see this.

[Rick]

consumptionjunction,You will experience lower efficiency when brewing higher gravity beers because you do not get to rinse the grains with as much sparge water as you would in smaller gravity beer. You can always compensate with more base grain in the mash or add some light DME after the sparge to reach your desired gravity.I have question for the more experienced larger gravity beer brewers; Does extending your sparge time increase your effeciency in these beers? It makes sense to me that the longer the sparge water is in contact with the grains, the more sugars that can be extracted from them.Rick

[BrewerGeorge]

It's simply a matter of the water to grain ratio. IMO, it's not so much the mash tun that limits efficiency as it is the desired boil volume. If you increase the pre-boil volume so that the water:grain ratio of a big beer is similar to the ratio of a typical beer, your efficiency should be similar as well. Of course, that will necessitate a longer boil time to drive off the extra water.

[consumptionjunction]

I guess this leads me to a rather difficult question, because I have never paid attention to remainder volume in my previous mashes. I have a 10 gallon rubbermaid (one of the tall circular ones) with a SS manifold, and I will have about 20-22 lbs of grain. What would be the maximum water:grain ratio in this or a similar case? I really would like to maximize the water:grain ratio but don't want to run out of space and come up short on my mash temp, so any personal anecdotes are welcome.

[JReigle]

I guess this leads me to a rather difficult question, because I have never paid attention to remainder volume in my previous mashes. I have a 10 gallon rubbermaid (one of the tall circular ones) with a SS manifold, and I will have about 20-22 lbs of grain. What would be the maximum water:grain ratio in this or a similar case? I really would like to maximize the water:grain ratio but don't want to run out of space and come up short on my mash temp, so any personal anecdotes are welcome.

You should be able to get about 22lb @ ~1.4qt/lb in that cooler, depending on how much dead space your manifold introduces. I think any strike water calculator should get you in right place for mash temperature.However, I think the ratio George was referring to has more to do with the total volume of water that passes through your mash in relation to the amount of grain, not just the mash strike water ratio.

[BrewerGeorge]

...However, I think the ratio George was referring to has more to do with the total volume of water that passes through your mash in relation to the amount of grain, not just the mash strike water ratio.

That's correct. If you're batching and you run out of room, you can do a 2nd or even 3rd sparge. Fly guys can just sparge longer.

[consumptionjunction]

Okay, so let me know what you think about this: Currently I collect about 5 gallons of first runnings. Knowing the grains are pretty saturated and that I only need two gallons more to fill my brew-kettle, I add about two more gallons to the mash-tun, let it sit for a bit, and take a second running (which usually fills my kettle just fine). I managed to get a pretty good efficiency doing this and didn't think much of it. But what you're telling me is that I should fill up the mash-tun as much as possible for the batch sparge, top up my kettle, and do whatever I desire with the remaining less concentrated wort? And that this would generally give me a higher concentrated "top-up"?

[BrewerGeorge]

Okay, so let me know what you think about this: Currently I collect about 5 gallons of first runnings. Knowing the grains are pretty saturated and that I only need two gallons more to fill my brew-kettle, I add about two more gallons to the mash-tun, let it sit for a bit, and take a second running (which usually fills my kettle just fine). I managed to get a pretty good efficiency doing this and didn't think much of it. But what you're telling me is that I should fill up the mash-tun as much as possible for the batch sparge, top up my kettle, and do whatever I desire with the remaining less concentrated wort? And that this would generally give me a higher concentrated "top-up"?

Not quite.If you're getting good efficiency for normal beers with your methods, I wouldn't make any changes. My comments were directed at overcoming the natural drop-off in efficiency that occurs with high-gravity brews. The drop-off happens when the ratio of water:grain is less than a typical-gravity brew. The size of the brew kettle tends to be the limiting factor in how much people sparge. If that wasn't a limit, you could simply sparge more water on the high-gravity brews to restore the water:grain ratio, boil away the excess and efficiency should be very similar to your normal brews.

[JReigle]

You basically need to decide what tradeoff you want to make. Do you use more grain (based upon reduced efficiency) and collect your usual volume and boil your usual amount, or do you use less grain (based upon your normal efficiency), collect more runoff and boil longer.Obviously the "more grain" approach has limitations in that your mash tun can only hold so much volume. The "boil longer" approach has it's drawbacks in that it's going to take more time doing additional sparges, more time in waiting for wort to boil down and burns more fuel. IMO "more grain" is easier and arguably cheaper.Your first time through with a high gravity beer is certainly going to be a bit of a learning experience since you're pushing the limits of your equipment. I went into it anticipating my normal runoff and collection volumes, but added ~15% more grain to compensate for the hit on efficiency. After I was done and had this data in mind, I could easily tweak my parameters to dial in the HG recipes. You'll probably want to ballpark your first attempt and feel out your system as you go.

[consumptionjunction]

So this question is somewhat off topic, but the answer will help me determine whether I should take a larger second running and boil it down. After the first running, if we can assume for the moment that the wort is homogeneous in sugar concentration, how much does the protein affect a refractometer reading?