What am I doing wrong?

[pmoneyismyfriend]

I can't hit a preboil gravity to save my life. I recently purchased new equipment to aid in my efficiency, with the FF from Northern brewer.
For the most part, I follow recipes from BLCS, I always input the recipes into brewersfriend. I've had my water analyzed by Ward labs, I use Bru'n water to calculate my additions. My mash temp is dead nuts. I am not sure what my ph is, I use test strips and don't have any faith in them, with a room temp sample, which begs the question, if your ph is off what can you do about it after the test. But according to Bru'n water, it's in range. I fly sparge. Regardless of what I brew, I always have to add DME. For my recent brew, 2.5 lbs for a 7.5 gallon boil Belgian Dark Strong. I don't get it.

 

[pmoneyismyfriend]

BCS (Brewing classic styles) not BLSC, I'm a dork

 

[doug293cz]

You don't give us much to go on. The information needed to help you diagnose your problem is:

• Recipe
• Strike water volume
• SG of wort in mash at end of mash, after stirring and vorlauf
• Pre-boil volume and pre-boil SG (after aggressive stirring)
• Post-boil volume ond post-boil SG (i.e OG)

You could have a conversion efficiency issue, which is why you need to measure your conversion efficiency using the method here. All you need to know to calculate your conversion efficiency is the grain bill weight, strike volume, and SG at the end of the mash. Conversion efficiency should be greater than 90%, and 95% or better is achievable. Too coarse a crush and/or too short a mash time are the usual culprits for causing low conversion eff.

You could also have a channeling issue when sparging. If you get channeling, it means you aren't rinsing all the grain during the sparge, thus leaving behind lots of sugar. You want to keep 1" - 2" of water on top of the grain bed during the sparge, and run off at a rate of no more than a quart a minute, and slower if you have a small mash tun.

If you are using BrunWater correctly, it is unlikely that your mash pH is out of whack enough to cause efficiency issues.

Brew on

 

[pmoneyismyfriend]

15lbs pilsen
3lbs munich
1lb caramunich
1lb special b
1lb aromatic
.5lb wheat
.5lb melanoidin
22 lbs grain 1.3 - 1.4 qts per pound plus 1.25 gal for false bottom so 8.75 stike.
preboil volume is 7.5 gallons, this is when I take my gravity reading. 1.07 (this is the adjusted number for temp) I should have been at 1.082
The post boil volume is 6 gallons and the O.G. was 1.093, I still have sugar to add which if I would have added to the end of the boil would have calculated and additional .008. The target was 1.11 but I'm short because I didn't have enough dme to give me the gravity I needed.

My sparging is exactly how you have described

 

[doug293cz]

I don't see any real issues here, other than overestimating the predicted efficiency for a large beer. I can't simulate a fly sparge, but a triple batch sparge will be close, so I simulated that. To get your 1.070 pre-boil SG at 7.5 gal I only had to drop the assumed conversion efficiency to 94%, which is a fairly reasonable value for a typical fly sparge crush.

Brew on

 

[acidrain]

preboil volume is 7.5 gallons, this is when I take my gravity reading. 1.07 (this is the adjusted number for temp) I should have been at 1.082

How are you measuring your SG? What is the temperature of the sample?
Did you stir the hell out of it before taking the sample?

 

[pmoneyismyfriend]

hydrometer, I don't recall the temp at this point. What ever the temperature was, i entered it into the brewersfriend software along with the gravity and got my adjusted gravity reading. I stir to equalize the temp, I wouldn't say I stirred the hell out of it.

 

[RM-MN]

Who mills your grain? The quality of the milling has the most impact on mash efficiency.

 

[pmoneyismyfriend]

i order the grains milled. I think the next time I order, I will try double milling. I think it's about the only thing I haven't tried yet

 

[Dog House Brew]

My guess is Grain crush 1st. 2nd is maybe water to grain ratio related to sparge. On high gravity beers I drop my W/G ratio to increase my sparge. Also my sparge on a big beer takes me a little over an hour for 12 gallon batches. You may be sparging too quickly. It also made a big difference making sure I get the grain to 170 before I start my sparge. 3rd would be making sure you have all your losses calculated for your equipment to become consistent. PH strips, in general, read .3 low, keep that in mind. Bwater predicts ph extremely well. I doubt that is your issue. I used to drop off the map for big beers. I would drop to 65% or lower. I made the changes and run right at 80 to 83% for about beer now.

 

[glugglug]

It took me a few brews on my system to get things dialed in. I lowered Brew house efficiency. I think my biggest thing was my grain absorption was off. Also, I know you should brew what you like to drink, but these are huge gravity beers your brewing. Maybe brew some lower gravity beers until you get it dialed in. It’ll also save you some money.