Efficiency Help

[Hex23]

I'm just beginning with AG, but you stir right before you vorlauf? I thought that you wanted the grain bed to settle so that the grains would act as a natural filter. For my three AG batches, I've been stirring when I add the water, then at 30 minutes in, then letting it settle and then vorlauf, drain, sparge, stir, settle, vorlauf, etc.

I could be wrong - just my understanding.

It depends on whether you are batch or fly sparging. For the former it is important to stir each batch before sparging. The vorlauf will clarify and set the grain bed. I don't think it would be wrong to stir before starting to fly sparge, but I don't think it's common or necessary.

Edit: On reading your question closer, I see your issue is not whether you stir or not, but rather whether you stir right before vorlauf. Still, I don't see a need to let it settle. The vorlauf will accomplish that.

 

[tnlandsailor]

I skimmed this thread and this may have been mentioned, but I didn't see a mention of volume measurement. How carefully is the wort volume being measured? This can have a pretty significant effect on efficiency calculations.

On the PPG issue, this is something that the malster tests and provides when selling malt. At the LHBS level, these numbers aren't usually available. However, if you plan on 36 PPG and the malt only delivers 34 per the malster, then your efficiency calculation shows a lower efficiency even though this isn't case. You are planning on something that the malt cannot deliver. This is the same if your malt is old or has been stored improperly (high humidity or high temp), or worse yet, pre-crushed and sat around a while. Your gravity ends up low and you think it's an efficiency issue when it's really not.

The whole efficiency argument gets pretty convoluted and you end up comparing apples to oranges. Measuring efficiency is one thing, trying to improve your efficiency is another. Give this a read:

The Efficiency Myth

On the improvement side, I'll echo the posters who advocate the crush as a significant contributor. I have found that the husk needs to be completely shed from the grain kernel. When you run grain through the mill and you pick up a kernel, sometimes it can be crushed but sill mostly inside the husk. This makes it hard for the water to get in and do the conversion. Try milling twice at a slightly looser setting. The first pass will actually crack the gain into pieces, the second pass will assure that the husk has been completely shed from the kernels.

 

[cch0830]

The Efficiency Myth

Awesome article!