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Adding DME DURING Fermentation

I brewed up a 5 gallon batch of something similar to the Northern Brewer’s Rebel Rye Porter last night.
About half way through my batch sparge I noticed my valve was about 1/4 open and resulted in terrible efficiency (for me).
I fell short 10 points - 1.061 from expected 1.071. My IBU’s will definitely be effected recalculating to almost 50!

I don’t want to simply add corn sugar to raise the gravity. This will effect the body and flavor.
I’ll be adding 16 oz of Rye Whiskey and oak chips to secondary and need to preserve the flavor of the malt/ body as not to have a thin, hoppy, hot mess.

I’m thinking to make a quick starter like solution of DME and add it to the primary to make up the gravity and add it as malt. not sugar.

Has anyone had experience or thoughts on this?

Sure no problem adding it to the primary. Best to do it before fermentation starts. You can always add it when you rack to the secondary

Yeah, It started about 3 hours ago.
Just pour in secondary with the whiskey and oak, huh. Would now at the beginning of primary matter?

You could add it now but I like adding it to the secondary because adding some fermentables at secondary will restart the fermentation and scrub some oxygen that may have been introduced on the transfer

I don’t batch sparge so please explain how your ball valve being 1/4” open affect you efficiency. Too slow of run off? Maybe @denny could explain how to slow of run off can affect batch sparge efficiency.

This is going to be a touchy subject speed of your first running and how it can affect your efficiency. Because there is a lot of opinions… Some say that draining your mash tun as fast as you can is best with a theory that the sugar can get caught and stick to your milled grain if you drain it to slow . Others claim that a slow running gives the same efficiency and run less of a chance for extracting tanning and oxigenating your wort. Here is the best advice if you believe you lost efficiency due to your sparge speed. Recirculate your first running and see if it makes a difference. There is other things that can affect your efficiency

Lots of variables here. Dough balls due to not stirring well, hit the right temps, different crush, mash tun design…

I usually fly sparge only because my system was designed for it and it works for me but here is a thought. Draining it fast seems like it would drain the wort all at once like pulling the plug in a bath tub. Slowing it might give the wort time for channeling, cutting little rivers in the grain and not picking up all the sugar on the way.

I agree with @damian_winter about recirculating also. With fly sparging I always recirculate for a while to set the mash bed just to prevent channeling. Maybe next time just open the drain all the way and see if it works. If not after that recirculate. If all else fails add more base malt. It’s cheap enough.

Stirring, the vorlaufing, then rinsing… repeat, repeat… Sounds as though there was some channeling, which means, the hot strike water followed the same path and therefore left some sugar behind, hence the strirring and vorlaufing process… Sneezles61

There are opinions, and then there’s science. Science says that runoff speed will not adversely affect a batch sparge. You can runoff slowly ( a waste of time) r you can run off quickly, which is what I do. In dozens of tests I’ve done, I’ve found that it just doesn’t matter. The idea of sugar “sticking” to the grain if you run off too slowly has no basis in reality. The sugar is in solution, it’s not a separate thing floating around. Likewise, the idea of running off quickly extracting tannins is a myth. I can’t think of any mechanism to explain it.

Hello hd4mark4h!
I remember you from the old BrewBoard forum of the early 2000’s.

There are two things I can ‘blame’ here.
I used 5 gallons to mash and single batch sparged with 4. I would normally split the 4 gal into 2 - 2 gal sparges.
I usually do 10 gallon batches and double batch sparge. In my opinion this rinses the sugars out very well. My eff % is always in the low 80’s measured at fermenter.
The second, I crush my own grain. This batch was a spur of the moment and I didn’t stop the LHBS from crushing the grains as I was browsing around the store.Who knows.
I make positively sure I have no dough balls and my mashing techniques are my usual of many years. So, it has to be sugars left behind (think close to a first running only) or the crush. I would not ever think to blame the LHBS of their measuring weight at purchase.

I’m adding DME with the whiskey and oaks chips added in secondary.

If you are rinsing the sugars in a batch sparge, you’re doing it wring. You want to drain them, not rinse them. Your problem sounds like a poor crush. That is always the #1 problem in poor efficiency.

See I told you this was going to be a touchy subject lol. The theory of the sugars sticking to the gain when draining your mash tun slow is not that the sugars are soluble. In science it’s the saturation of the grain and sugar being soluble soaked into it. Although the grain is already saturated the slowing of the run off creates a lighter force allowing a degree of the sugars to saturate into the grain bed kinda like a sponge. Allowing it to drain faster the force is stronger and in away a creates a vacuum of sorts pulling some of the soluble sugars that has saturated into the grain… But this more applies to a no sparge batch because when batch sparging the left over sugar are captured with your second runnings. I too like you Denny just open it up and let it drain as fast as my valve will allow.

I start slowly so as not to compact the grain bed. After I return the vorlauf to the tun (maybe 1-2 min.) I open it up. I’ve done sparges of all speeds and there is no way that slowing down the runoff will have any more than a theoretical effect.

Thanks for the clarification @damian_winter and @denny.

And I would suspect the crush before the runoff.


Probably the crush. I started getting better results crushing my own.

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I won’t touch any of this now… not even with a mash paddle!! Sneezles61

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