Never Hits Gravity - What am I doing wrong?

[blitzballer2201]

It seems like for the past few years I never hit my gravity, I have been making adjustments to my brewday that help with "improving" gravity and I never seem to hit it. So im reaching out to you all for help! Ill lay out what a typical brew day is for me and please let me know where I am screwing up.

info on equipment -
I use clawhammer biab electric system.
Ingredients come pre-milled and typically from northernbrewer.com (sometimes from local shop)
I use a refractometer that is calibrated to the water that I am brewing with that day before heat.

I use Brewers Friend and Beersmith3 for my calculations.

Brewday -
I use 7gl of spring water for brew day I buy at a store since I am on a well, use all volume at start, no sparge since its biab.
typical mash in temp is 157 - after adding grains I hold 152 for an hour is typical (this is used with a controller so temperature is held very accurately)
After 10 minutes into mash I always take a pH reading, adjust with lactic/phosphoric acid to appropriate levels.
after 50 more minutes I start to mash out - hitting 170 mash out temp takes about 30 minutes (raise temperature not infusion) than I hold that for about 10 minutes. So grains are sitting in water for about 2 hours.
After mash out I start to drain the grain in the grain basket. - Dump the grains
Once I have collected my wort, I take my first refractometer (use calc to adjust for temperature) reading to see my pre-boil gravity - I ALWAYS anticipate never hitting my pre-boil gravity.

There is something.. in the above steps that I am doing wrong. My pre-boil gravity is always off. Sometimes by alot. Last weekend it was off by 20 points.... I ended up just adding 2lb of DME since thats all I had. I would have needed to boil off like 2 gallons of water to hit my pre-boil gravity so I opted for the DME.

Once my pre-boil gravity is achieved I typically hit my OG. But hitting my pre-boil is always off.

The only things I can think of that maybe I can try:
1. buy grains not milled, buy a mill, mill on brew day.
2. bring back sparge, I have not sparged since I swapped from old cooler setup to new biab electric since they said to not sparge with biab. But I was not hitting gravity when I used my old setup either so not optimistic.

 

[VikeMan]

It seems like for the past few years I never hit my gravity,

If I was never hitting my expected gravity, I'd be looking at where the expectation is coming from. Specifically, what's the expected mash efficiency, and is it reasonable? IOW, what is the mash efficiency assumption in the software you're using to build your recipes, and is it reasonable given your equipment and process?

If you're interested, I recently posted a slide presentation on Mash Efficiency and Brewhouse Efficiency on my club's web site.
http://sonsofalchemy.org/library/

 

[3 Dawg Night]

If you're interested, I recently posted a slide presentation on Mash Efficiency and Brewhouse Efficiency on my club's web site.
http://sonsofalchemy.org/library/

Great set of slides! Thanks for sharing!

 

[Jim R]

The only reason not to have a grain mill is to save a little money. It certainly doesn't take much time to do this the day before brew day. When I first bought a grain mill I had the opposite problem. I was going over my goal gravities and had to back off on the mill crush a little.

 

[blitzballer2201]

what's the expected mash efficiency, and is it reasonable?

My expected mash efficiency is always 70%, do you believe that is unreasonable for my equipment?

pump to recirculate mash/contoller to hold temp/mashout/pH measured?

Also thanks for the message, ill check this out.

 

[RM-MN]

Ingredients come pre-milled

When you depend on someone else to mill the grain you get the efficiency that their milling will allow. You can mitigate that by mashing longer but there is a limit to how much that helps. With BIAB you can deal with a very fine crush. Some have taken the time to run their grain through a blender to get the particle size down but the real solution is to get your own mill. Corona or Victoria mills work well for BIAB and are pretty cheap.

When I first bought a grain mill I had the opposite problem. I was going over my goal gravities and had to back off on the mill crush a little.

I went the opposite and just increased my batch size. The recipe is for 2 1/2 gallons so I make 4 and get the right OG.

 

[VikeMan]

Does the Clawhammer system have any deadspace (space with unrecoverable wort) when mashing? If so, that would reduce efficiency. But even if not, depending on the crush, 70% might be a high expectation for a no sparge process and mid to high gravity (i.e. large grain bill) beers. Mash efficiency will (and should) vary by grain bill size.

 

[Oginme]

The first thing I would recommend is to take your measured readings for gravity and volumes and plug them into the 'session' tab in your BeerSmith recipe. On that same tab, you will see in the lower section an area which compares your 'BH Efficiency' which comes from your equipment profile and your 'Meas Efficiency' which is the calculated actual brew house efficiency based upon your measurements. If your measured efficiency is greatly different from your estimated efficiency in your equipment profile, then make the adjustment to your equipment profile for your next recipe.

Note that in BeerSmith, each recipe is its own archive so when you make your change to the equipment profile you need to reload that profile into your recipes for it to be active. Once you have come to grips with what your actual efficiency is, you can figure out the best ways to improve it. (hint: crush).

If I remember correctly, the clawhammer system is basically a BIAB type of mashing. Start by seeing if you can order your grains double crushed or crushed for a BIAB mash.

 

[Velnerj]

Do you know how to calculate what your actual efficiency is? Taking the total amount of sugars possible divided by the actual sugars extracted. You should be able to find the grains extraction efficiency from the malstter and can calculate pounds per gallon (or grams per liter) etc from that.

Otherwise blindly picking 70% every time and getting a bad result will get you no where. Once you are able to calculate your actual efficiency (and if you've taken good notes from past brews the more accurate you'll be) then you can adjust your recipes accordingly and hit your expected targets.

 

[kevin58]

Another thing about using Beersmith is that you must create your own equipment profile if you expect your results to reflect the software estimates. The profiles included in the software are from someone else's system. They are mostly, if not entirely, user created. Even Brad Smith recommends using these default profiles only as starting points to customize your own profile. If you skip this step or use guesswork then you will will be forever frustrated by your results not matching the software estimates.

 

[seanjwalker1]

I never get a correct reading with refractometers , I've had 2 and I'm retired nurse who used them every day. I ditched them both and strictly use hydrometer. Also you can still sparge with BIAB. Nothing like rinsing your grains to grab hold of that extra sugar. Even when I used to do BIAB, I still would vorlauf a couple quarts before collecting. Also make sure you don't use too much water in your strike. Are you making sure your water is at 152-154°after you have added water and mixed grains? You may need to add a little more 168° water to raise it up to proper mash temp. I've missed my target a few times being rushed and sloppy with temp reading. Just my 2 cents. Get a hydrometer! Even the cheapest ones work good. At least so you can compare.

 

[TheMadKing]

All of the above are good advice. I'll add a few things:

Refroctometers work fine you just have to make sure you stir very thoroughly before taking the sample because the wort stratifies by density quickly. Also let your sample cool on the refractometer lense for a couple minutes, they only work well at the calibration temp (usually 68F) even with ATC. Refractometers also don't work in the presence of alcohol so you need a hydrometer for any post fermentation measurements

Check your recirculation speed. If you are recirculating too fast then you will get channeling which drops your efficiency very quickly. Start with your pump flow valve completely closed and open it slowly until you just barely have flow and keep it at that level. I suspect this is your issue.

Stir your mash thoroughly when you dough in to make sure you don't have any dough balls.

Double check your volumes. It's easy to assume volume markings are correct but it's best to check

 

[TheMadKing]

Does the Clawhammer system have any deadspace (space with unrecoverable wort) when mashing? If so, that would reduce efficiency. But even if not, depending on the crush, 70% might be a high expectation for a no sparge process and mid to high gravity (i.e. large grain bill) beers. Mash efficiency will (and should) vary by grain bill size.

Agreed

Typical numbers from my old BIAB setup were 75% BH efficiency on an average sized grainbill, and then I would expect 60-65% efficiency for very big beers. I saw in the 55% range with a barleywine once and ended up batch sparging in a bucket to get a boost.

So it's important to make sure your expectations match the beer you're making as well OP

 

[Bobby_M]

The most likely problem is the crush. Request a double crush next time.

 

[blitzballer2201]

Thanks all for the comments, really appropriate it. Based on the information in the thread I did more research in addition. Ill be making some changes.

1. Looking into a grain mill to start to do finer crushes, or if ordering from stores asking for double crushes until I can get my hands on one.
2. Double checked my mash/equip profile in beersmith, made some more accurate modifications to those profiles.
3. im going to start "squeezing the bag" so I can reduce my grain absorption which will in turn reduce my strike water volume.

Still going back and fourth on the Sparge vs No Sparge. I read an interesting article sited by Brulosophy : Misconceptions - Brew Bag Myths Explained the following:
"A water to grain ratio of 2.6 or higher aids in washing the grain and coupled with squeezing the bag adds additional gravity wort to the kettle without dilution. This process, which produces undiluted pH controlled wort can't be duplicated to the same degree when sparging. You can sparge by holding back some of the total volume, but the resulting gravity will be the same. "

 

[Velnerj]

Though I thoroughly enjoy brulosophy, I'd take their advice with a grain of salt. I'm not being critical, but you'd have to duplicate their equipment and their process to reach their same conclusions.
Basically what I'm saying is use brulosophy as an hypothesis and try it for yourself if you reach their same conclusion. You may be surprised.

 

[VikeMan]

Still going back and fourth on the Sparge vs No Sparge. I read an interesting article sited by Brulosophy : Misconceptions - Brew Bag Myths Explained the following:
"A water to grain ratio of 2.6 or higher aids in washing the grain and coupled with squeezing the bag adds additional gravity wort to the kettle without dilution. This process, which produces undiluted pH controlled wort can't be duplicated to the same degree when sparging. You can sparge by holding back some of the total volume, but the resulting gravity will be the same. "

Sparging, either batch or fly, when done properly, will get more sugars into the boil kettle than not sparging. Unless by "holding back some of the total volume" the article means some of the actual post mash wort (and not water), and then running the wort through the bag, it's wrong. If it were the case that sparging does not increase efficiency, nobody would do it. The math is a little tedious, but can be demonstrated if necessary.

I would also emphasize that the "when done properly" part is key. And with BIAB, it can be pretty tricky, depending on the setup/method.