Need Some All Grain Help

ronzonie7 · 11-05-2009, 12:06 PM

We brewed our third batch last night, opting to move away from extracts, over to the Boil in a Bag Mash/Sparge method. Things, generally, went well. We mashed at around 152-155 degrees, pouring 3 gallons in and getting about 1.67 gallons out. The sparge water went in at around 170-172, again 3 gallons, and we got back over 2 gallons of that (closer to 2.5 gallons). The wort was boiled for about 75 minutes.

The recipe, loaded into beersmith, called for a OSG of 1.092, I believe. We hit 1.062. That's a pretty big difference, and we're trying to figure out where we might have gone wrong. This was a 3 gallon batch, but we ended up with over 4 gallons of wort in the pot. I'm wondering if we 'missed' something in the mash/sparge process, or if our boil wasn't rigorous enough to properly burn off enough wort to concentrate the sugars? We had only about half an inch of boil off, in the pot...not much, at all, in a 7 gallon pot.

The recipe is here, at our blog, along with a step by step process of what we did.

Until we get a mash tun setup, we'd like to be able to utilize the boil in a bag method for some All Grain experience. In fact, we're gunning for an All Grain Saisson this weekend, but we need to know our process is proper. Anyone have any advice?

JesseRC · 11-05-2009, 12:30 PM

Well 1 gallon extra wort is a lot. I think you already know your answer. Go into beersmith and batch volume to 4 gallons and keep ingredients constant. I bet you get the same OG you ended up with. It will still be a great beer.

**Pappers_** · 11-05-2009, 12:34 PM

Hi, I think I told you this before - I like your blog!

I don't do "brew in a bag" so can't really address your issue from experience. One thought, though, is to take a hydrometer reading with 10 minutes to go (you'll need to adjust for temperature) and then add dry malt extract if you need to raise the original gravity.

You've still got a big beer, fyi - I bet it will turn out well!

ronzonie7 · 11-05-2009, 12:48 PM

Quote:

Originally Posted by Pappers

Hi, I think I told you this before - I like your blog!

I don't do "brew in a bag" so can't really address your issue from experience. One thought, though, is to take a hydrometer reading with 10 minutes to go (you'll need to adjust for temperature) and then add dry malt extract if you need to raise the original gravity.

You've still got a big beer, fyi - I bet it will turn out well!

That's an interesting suggestion. I'll certainly remember that one. Seems like a reasonable fix, if you really need to boost it.

We're not overly concerned with the ABV's, as much as we want to be sure we are getting maximum bang for our grain buck. I feel like the mash went very well, but I'm wondering if it's a sparge issue that boosted our volume? We used a website to down-convert a recipe to a 3 gallon batch, and it recommended the water amounts we used. About 3 gallons mash, 3 gallons sparge, for our grain bill. I guess it makes sense that in the sparge, the grains are more spent, so they take on less of the water? Should we have maybe tried to expunge a little more out of the grain before sparging?

**pdbreen** · 11-05-2009, 01:00 PM

Looking at what you did, the last half gallon of water was a significant dilution.

Some rough math:

2.5gal * 62sg = 155 total gravity
155tg / 2gal (volume before dilution) = 77.5 sg

77.5 sg * 4gal (post boil volume) = 310 tg
310 tg / 3gal (target volume, had you boiled more off = 103 sg (1.103)

So, it looks like you got the sugars converted, but just need to work on hitting your volumes. This may take a few iterations to figure out exactly what your boil off is and then work backwards to figure out the sparge volume required.

Scooby_Brew · 11-05-2009, 01:12 PM

It looks like your recipe is calibrated for 75% efficiency and you got ~52%. I think you will always get a poor efficiency out of a bag sparge method. I would leave this batch alone now, you will still get a good brew out of it. Just start thinking of moving into 5 gal batch sparge or fly sparge method.

ronzonie7 · 11-05-2009, 01:20 PM

Would calibrating for less efficiency reduce the volume of water used in the mash/sparge?

**pdbreen** · 11-05-2009, 01:23 PM

Quote:

Originally Posted by pdbreen

Looking at what you did, the last half gallon of water was a significant dilution.

When I re-read what you did, I see that you didn't add water, but more wort. So, the calculation is now:

62sg * 4gal = 248 tg / 3gal = 82sg

So, you lost about 20 points by missing the target volume.

GrizlyGarou · 11-05-2009, 01:34 PM

Quote:

Originally Posted by ronzonie7

Would calibrating for less efficiency reduce the volume of water used in the mash/sparge?

Nope. It would change the calculated OG for you, though. The water volumes are to get the grains to the right temperature and be thin enough to let the sugars dissolve into the water once the enzymes convert them.

I've never tried the mash in a bag, but I've read that you want a really fine crush for it. That'll make a huge difference in your efficiency, but a high efficiency isn't always the best. Consistent, good wort is the important part. Did you leave the bag to sit in the water, or did you swish it around at all?

shortyjacobs · 11-05-2009, 01:47 PM

Looks like you just overshot your volumes. Boil more off or use less water next time. This time will still make Beer.

Note that using a hydrometer on hot wort will give you wonky readings. The temperature correction calculations are guestimates at best. The only way to really know is to cool a sample down below 100F, then use temperature correction calculations, (they are more accurate the closer you are to your hydro's calibration point, usually 60F).