Original Gravity Low

[bracconiere]

Next brew day won't be for a month or so.

sometimes i forget about real life! i'm betting a 80%! all bets welcome!

 

[jrgtr42]

if that's a jab at me, i'm still learning! i have to!

(if i get 75% with one batch, and 85% with another from the same bag of barley, it's something to look into! )

Not you in particular - but ther's a few I've seen that do. Yeah, off the same bag, if you're getting that wide a difference, it's something to look at.

@jrgtr42 I'm off by .008 to .022. Readings are taken after boil. From what I'm reading here, I've been sparging completely wrong. The books aren't really clear on this stuff.

.008 is close enough to the margin of error I wouldn't worry too much about it.
.022 is pretty far off. You're not really wrong in sparging how you are - fly sparging does that, slowly running off wort by replacing it with water from above, and you want to have some above the grain bed. In theory you keep tabs on your gravity when sparging, and stop when you are somewhere around 1.008, I think - it's been a while since I read up on this. Also in teory, you'll have your pre-boil amount spot on at that point.
Personally I batch sparge - it's way easier and I didn't find a measureable difference in the beer at the end. In this case, run off everything in the mash, and you can do it s fast as you want, rather than spending an hour fly sparging.
Then add in the second strike water addition, stir it in, and let it sit around 15 minutes. Then run that off and Bob's your uncle. I will start heating the first runnings while the batch is sitting, and if I time it right, it's as hot as it'll get before boil when I add the second runnings. That minimizes time for the whole thing to come to a boil.

 

[hotbeer]

I didn't see that you addressed @Sam_92 's question of how much you put in the fermenter.

If you are boiling 7.5 gallons for an hour, then most of us will have 6.5 to 6.0 gallons left at the end. So if the recipe was planning on 5 gallons going into the fermenter, it was probably thinking there'd be more boil off or you are misunderstanding how much water it's asking you to use.

In the short.... too much water for the amount of grain used will leave you with a lower SG.

OG is typically the SG of the wort going into the fermenter after the boil.


There are also some methods and just getting more experienced at mashing and sparging that will allow you to get more sugars from a fixed amount of grain. So poor sparging techniques could be an issue too. But I'd suspect just not enough water boiled off or too much used to get to the kettle.

 

[bracconiere]

You're not really wrong in sparging how you are - fly sparging does that, slowly running off wort by replacing it with water from above, and you want to have some above the grain bed.

 

[RM-MN]

Then add in the second strike water addition, stir it in, and let it sit around 15 minutes.

When batch sparging there is no need to wait. Stir the cool (doesn't need to be heated) into the grains as soon as they have been drained. Stir well to get the sugars separated from the grain, then drain.

 

[Plastic Brewkettle]

@hotbeer I'm putting 5 gallons in the fermenter. I tried a 6.5 down to 5.5 (or so) gallon boil a batch or so ago and still had low OG numbers.
@jrgtr42 I may try batch sparging next time.

 

[jrgtr42]

When batch sparging there is no need to wait. Stir the cool (doesn't need to be heated) into the grains as soon as they have been drained. Stir well to get the sugars separated from the grain, then drain.

See, I've always read to have the water at mash-out temps, and allow to sit for a little bit to get the most out of the mash.

 

[day_trippr]

That would be misinterpreting the point of the high temperature "mash out" - which is simply to kill ("denature") the saccharification enzymes extant so as to "fix" the fermentability character of the wort...

Cheers!

 

[bracconiere]

That would be misinterpreting the point of the high temperature "mash out" - which is simply to kill ("denature") the saccharification enzymes extant so as to "fix" the fermentability character of the wort...

Cheers!

@Plastic Brewkettle , obviously is set up for fly sparging if he has a HLT, sparge arm...and just needs to keep the level above the surface....to prevent "pitting" in the grain!

the point of a sparge arm for fly sparging is to keep the water ABOVE the surface, while not drilling holes in the grain bed...

 

[RM-MN]

@hotbeer I'm putting 5 gallons in the fermenter. I tried a 6.5 down to 5.5 (or so) gallon boil a batch or so ago and still had low OG numbers.
@jrgtr42 I may try batch sparging next time.

There are only a few causes of getting low OG if you have the right amount of grain. A bad sparge can be one of those things but the most common is a poor crush. If the water can't get to the starches and activate the enzymes, you don't get all the starches converted to sugars. Then some of the sugars that do get converted may not leach out of the grain particles. A conventional mash tun requires a compromise between good conversion and being able to drain the mash tun. Too fine of a crush and the grain husks are shredded so they won't form the filter bed. Too coarse of a crush and you get poor conversion. Most LHBS would rather sell you more grain to achieve the expected OG than to risk customers being mad because they get a stuck mash.

 

[Plastic Brewkettle]

@RM-MN So I would probably buy a grain mill (I've been looking at them anyway) but I'm not quite ready. Northern Brewer has the hand crank one but it strikes me as entry level and I don't want to be buying another one in 2 years. If I get a mill, that means I start buying grain in bulk and roasting my own. Geez. Then I've got to start a hop garden and a yeast nursery. Then I'll need a water well with a treatment plant. All this on a garage-brewer's salary.

 

[hotbeer]

@hotbeer I'm putting 5 gallons in the fermenter. I tried a 6.5 down to 5.5 (or so) gallon boil a batch or so ago and still had low OG numbers.

I guess I ask an incomplete question. And maybe the info has been given already but I haven't looked yet.

When you put 5 gallons in the fermenter was there much wort leftover that didn't get used? If so, then that is lost sugar that could have been used to give you a higher SG.

So other than leaving yourself enough to maybe have for an OG sample your total wort produced should generally be the total amount you plan to put in the fermenter plus the water you need for evaporation losses during the mash and boil. Again, any wort you don't use is sugar you are throwing away that might have added to your SG.

You grain crush might leave you not extracting enough sugars too. For a traditional mash and sparge it might not work well, but I've been using a very old coffee grinder to mill my malts for BIAB. A burr grinder not a blade grinder. I get really good numbers for how much sugar I'm extracting.

 

[RM-MN]

@RM-MN So I would probably buy a grain mill (I've been looking at them anyway) but I'm not quite ready. Northern Brewer has the hand crank one but it strikes me as entry level and I don't want to be buying another one in 2 years. If I get a mill, that means I start buying grain in bulk and roasting my own. Geez. Then I've got to start a hop garden and a yeast nursery. Then I'll need a water well with a treatment plant. All this on a garage-brewer's salary.

You can spread those purchases over a few decades. I bought a Corona style mill and a paint strainer bag to start all grain and brewed a 2 1/2 gallon batch, full volume, no sparge and got a much higher OG than the recipe was written for. I've used one of the paint strainer bags for a 5 gallon batch (several actually) but went back to 2 1/2 gallon batches due to bad back and the desire to have more varieties of beer without drowning myself in beer.

This is the type of mill I have. They have gone up a bit in price since I got mine but still reasonable. With a little grinding I managed to fit a socket onto the shaft and with an adapter can run it with my cordless drill. (hammer drill to get sufficient torque to turn it).

https://www.walmart.com/ip/Tall-Cas...-grains-oats-corn-wheat-coffee-nuts/872352235

 

[bracconiere]

Then I'll need a water well with a treatment plant.

so you're familiar with RO systems? but didn't know to keep the water above the grain bed? the suspense is killing me! i'm going to be losing sleep until next month now!