Mash Efficiency

[threefrenchs]

My efficiency has dropped a bit over the last few brews. One issue is my new mill and setting up gap, but I wanted to get some thoughts on procedures from fellow brewers.

1. For a 10 gallon batch, how long do you sparge? I normally go 60 minutes but a few things I have read say I should be going 90 minutes.
2. I have the ability to heat my mash tun, but I worry about cooking the bottom. Thoughts on adding a little heat to the mash tun during sparging to keep the temp around 168?

Thanks for the input.

Robert

[dhempy]

Are you talking about Boil versus Sparge for 60 versus 90 minutes?

If you're talking sparge then I'll assume you're doing a fly sparge .. and unfortunately I have limited experience with fly sparging ... BUT I believe that most of what I've read suggests that fly sparging is done until one of two endpoints is reached .. either 1) You have pre-boil volume or 2) the runnings drop to a certain specific gravity. Some of the others here can probably provide more first hand experience.

As far as heating the MT directly, I would think that as long as fluid is moving you'd be find. My system has the ability to do both HERMS and RIMS and I will sometimes use direct heat to speed up the temperature rise to mashout temps AND for heat maintenance during batch sparging. In both instances, I am recirculating and I've never had any issues. But I do throttle that burner way down AND it is smaller than my boil and HLT burners.

All of that said, you're probably correct in that your mill gap is the culprit (assuming the other parameters are the same). Tighten it up a bit and see how you do. A stuck mash will tell you you've gone too far so go in small increments ... I don't know gap numbers off the top of my head any longer but perhaps others do.

Dan

[SamIam]

We try and do our fly sparge in about 45 - 55 minutes for a 15 gallon batch. Not sure I would add direct fire heat to the mash. I would think the wort is moving pretty slowly and the risk of scorching is too great but you could always increase the temp of your sparge water to 175. Just be careful about sparging too long at higher temps. As Dan pointed out, the biggest difference maker we've seen in efficiencies has been our mill. We got a big bump when we started milling our own and have been pretty consistent since. We set our roller gap to about .040 but it may differ for your set up.

[threefrenchs]

Thanks for the info. Yep doing a fly sparge, but I might need to try batch sparging on the next brew.

[brahn]

I target a 60 minute sparge for my 10 gallon batches. I will direct fire the mash tun if the wort is recirculating, but I don't do it during the sparge. While sparging the wort is flowing pretty slowly in order to hit my 60 minute target time. Plus, during the sparge you'd primarily be heating the wort that's on it's way to the kettle, not the grain bed. I use 175-185 degree water for sparging. The thing you want to avoid is getting the grain bed above 170. Assuming it's at or below 160 when you start your sparge, you shouldn't have a problem using hotter sparge water. If you've mashed out to 168, you may need to be more careful.

[bwarbiany]

1) My sparge is probably 30-40 minutes for a 10-gallon batch. It's possible that this is "too fast", but I routinely hit about 80% brewhouse efficiency according to beersmith for <1.055 beers, and usually above 75% for anything up to 1.080 or so, so I don't think sparge rate is all that important.

2) I do this, during recirculation if my temp is dropping, and if I end up direct firing during recirc, I continue direct fire during the sparge. My thought is that as long as fluid is moving and the fire is *very* low, you'll be fine. I've never had an issue with grain scorching to the bottom of the mash tun, and my old mash tun had a false bottom that actually made contact with the bottom of the mash keggle, so if it had been an issue, I would have seen it with that configuration. However, if you're using a manifold or hose braid type setup rather than a false bottom, this might not be a good idea.

I'd try a finer crush...