Remashing wort for efficiency

[t_met]

Yesterday's brew session had some problems with hitting the numbers. I had an extremely low efficiency (51% vs typical 68%). I think I know the reason(s) and is not the topic of the post.

I had already collected all of my wort in the the kettle when I observed the poor efficiency. I decided to try to correct this by partially refilling the mash-tun with the near boiling wort. I'm guessing the mash-tun was filled to about 1.5 quart/lb consistency. The "re-sparge" reached a temperature of 161F. I stirred this well to dissolve some sugars and recirculated until clear.

This was successful with increasing the efficiency (56%). I proceed with adding a 1.5 lbs of DME to reach desired SG. If I had to do this again, I would add more wort to mash tun. Hopefully I won't need to do it again and prevent it in the first place.

I just wanted to share the experience/experiment. And to hear if anyone can point out some side affects. I believe I checked the ph, and it seemed fine. As mentioned above, the re-sparge only got to 160. I can only think of introducing HSA.

 

[broadbill]

I think you were basically "rearranging the deck chairs on the titanic" with recirculating the wort.

The reason sparging works is that the grains contain a high concentration of sugar are mixed with water that has zero concentration of sugar. This creates a concentration gradient (grains =high, water =low) and sugars move into the water phase, hence "rinsing" the grains.

Sparging with wort is less efficient when sparging with water because it contains sugars already. That steep concentration gradients doesn't exist between grain and wort (although there is probably some) and rinsing/sparging isn't as efficient.

I guess what I'm trying to say is that although there probably isn't any side-effects from doing this, it probably wasn't all that efficient use of your time, either. Since you had to add DME to offset the efficiency loss, you could have just skipped this step.

 

[t_met]

Yes, that's what was concluded. I wanted to share the outcome.
I should have pointed that my set-up was a batch sparge. I think the original problem was having too much water in the initial mash, and not enough water left for the 1st and only sparge. My thoughts were that a lot of sugars were not dissolved with that 1st sparge. Rather than adding more water & sparge, I chose to use wort. I didn't want excessive liquid to boil.

It did have a 10% improvement, but not worth the effort.

 

[asterix404]

Also if you were using near boiling wort, you denatured all or most of the enzymes so the fact that you might have gotten a higher gravity was adding nothing fermentable into the wort, only more carbs or sugars that yeast can not break down. This is really what DME is designed for and it's why I always keep it on hand.

 

[t_met]

You are correct that the enzymes have been denatured. So this would mean there would be no more conversion of anything in the grain bed. However, there was left sugars in the grain bed. I was attempting to extract any sugars that were left there in the initial mash/sparging.

I wish I could have changed the title to "resparging with wort.."