Low FG

[okoncentrerad]

I just did a SG read on my third brew (american IPA) and like my previous two I'm getting a low reading, 1.006 after a week. The other two finished at 1.008 (american IPA) and 1.004 (british bitter) respectively. I have yet to get a good efficency on my brews and have miscalculated on all of them, estimating an efficency of 70% but only getting 60 - 65% (BIAB), thus missing my estimated OG with quite a lot.

Is the low FG because I miss the estimated OG with too much?

Could my pitching be a problem, with too much yeast for my (small) batches? I make 10 liters (~2.5 gallons) batches (in fermentor) with almost a full packet of dry yeast.

I have understood that the characteristic of the water may affect the efficency, but how big of a role could it play? (okay I know, it depends...)

 

[Ozarks Mountain Brewery]

the final gravity is directly related to the original gravity, the lower the original the lower the final, crush the grain finer and do a dunk sparge to get a better efficiency

 

[okoncentrerad]

Thanks! I buy my grain crushed but perhaps I should invest in a grain crusher of my own, been thinking about it.

 

[philjohnwilliams]

A grain mill is probably one of the best investments an all grain brewer can make. Not only can you cut grain costs by buying in bulk ( my lhbs sells base malt for about $1.25lb while it cost me about $.67lb if I buy it by the 55lb sack) but you can also customize the crush to best suit your setup.

 

[jeffpn]

I crush my grains at the lhbs, so I’m restricted to how they set it up. You could double crush if you want to. I do that sometimes. You shouldn’t have to double crush to get around 75%. Consider this tip. When you pull the bag of grains out, put them in a bucket, elevated from the bottom (use an upside down colander). Pour a gallon of water through the grains, and let it drain, don’t force it. When it’s drained, dump that water into the kettle, and pour another gallon of water over the grains. When all is said and done, make sure you haven’t overshot your preboil water volume. You should be close to 75% doing that.

 

[okoncentrerad]

I crush my grains at the lhbs, so I’m restricted to how they set it up. You could double crush if you want to. I do that sometimes. You shouldn’t have to double crush to get around 75%. Consider this tip. When you pull the bag of grains out, put them in a bucket, elevated from the bottom (use an upside down colander). Pour a gallon of water through the grains, and let it drain, don’t force it. When it’s drained, dump that water into the kettle, and pour another gallon of water over the grains. When all is said and done, make sure you haven’t overshot your preboil water volume. You should be close to 75% doing that.

Thanks, yes actually that's quite how I'm already doing it. My first two batches I had a water/malt ratio of 3:1 when mashing, but after some hints on a previous thread here I did mash at ratio close to 6:1. The missing water to reach my boil volume on all three occassions I added just like that, I guess it's kind of a sparging? On my last batch I also made sure to squeeze the bag rather extensively, something I was a bit shy of on my first attempts.