Clawhammer 120v 5 gallon system Efficiency

[Gbabcock17]

Just did my first brew day on my new clawhammer system. Really easy to use and I loved having the electric controller so I could set and forget at times throughout the mash and boil. I have been doing 1 gallon BIAB batches on a stove top for a year and never really bothered to calculate my efficiency because it was more just for fun. However I am wanting to take my brewing more seriously now that I have the 5 gallon set up. I calculated my efficiency to be only around 40% : / Anyone who brews on the clawhammer around 70+% efficiency that could offer some tips? Here's what I did:

-Double crushed grains on my grinders lowest setting
-Mash in at 130 for 20 minute protein rest
-Sacch rest at 152 for an hour
-Ramp to 170 and set there for 5 minutes till mash out
-Let grains drain over kettle for 15 minutes while I raised to a boil
-Rinsed grains with 1.5gallons of 180 degree water to get preboil volume up to 6.5
-Ramp the pump the entire duration of the mash
-Stirred grain bed every 15 minutes to prevent cakes from forming

 

[McKnuckle]

There are a lot of variables impacting efficiency. In the case of well-milled grain, appropriate temperatures, enough rest time, and circulation, there are two things that come to mind:

Grain bill and water volumes - Sometimes brewers make a mistake with a recipe, over-estimating extraction potential (OG). Other times they make a calculation error when determining efficiency. If you list these details, help will be forthcoming.

Mash pH - Was it within range, or really out of whack? If you don't know, then what kind of water did you use?

 

[Gbabcock17]

Grain bill was as follows:
-12lb pale 2 row
-0.5lb carapils
-0.5lb caramel 40
-0.5lb gambrinus honey malt
I was planning for an OG of 1.070ish if I hit a 70% efficiency. I do all my calculations on the brew cloud app.
My mash volume was 7 gallons and when mashed out and drained the grains before the sparge I was at exactly 5 gallons which was what I planned...0.125 gallons of water per lb of grain.
As far as water pH I do not know. It was my local tap water. Sounds like this is what I need to look into. For now I'll end up with a well hopped session beer haha

 

[McKnuckle]

I noticed that you didn't provide your measured OG, you just talked about efficiency and expecting 1.070. What was your actual OG?

I plugged your numbers into Brewfather. A 70% mash efficiency is getting you to 1.063. That is mash efficiency, not brewhouse. Brewhouse also takes into account your volume losses, such as wort left in the kettle or mashtun. It is always going to be lower than mash efficiency, because losses accumulate as the brewing process progresses.

We have to ignore these losses if we want to focus on your extraction performance in the mash.

A 40% mash efficiency gets you to about 1.036 with that grain bill and water volumes.

Also note that you have 13.5 lb of grain, so if you measured the starting and pre-boil water volumes accurately at 7 and 5 gallons, respectively, you would have absorbed 2 gallons into the grain, which is 0.148 gal/lb. Every detail matters in these calculations.

 

[Gbabcock17]

Cooled the wort to 70 degrees and took my OG before transferring to fermenter. 1.040 was what the hydrometer read

 

[McKnuckle]

Okay, give or take a gravity point and a few efficiency percentage points, you still need help. Just wanted to clear the air first about how the calculations were being done.

 

[Gbabcock17]

So if I'm understanding you correctly it sounds like my calculations don't fall too far from yours (using different apps grains could have slightly different potential based on quality)...I live in a rural area and while my tap water is treated I've read about runoff from agricultural chemicals and such being a greater risk in these areas water supplies.

Other ideas I had as well were use a bag even though the system has a grain basket so I can squeeze it at the end (I know that's controversial). And attempt setting the kettles lid with the spray valve running slowly on top of the draining grain basket to attempt vorlaufing

 

[McKnuckle]

Yes, not too far off; I think I got ~45% mash efficiency to match up with 1.040.

Squeezing the bag (yes, controversial) won't increase the amount of extraction. It only gets you more liquid wort of the same gravity as the rest of it. That's better lauter efficiency, which does contribute to mash efficiency of course, but perhaps not in the way you're most concerned with (gravity).

Your issue seems to be more conversion related - getting a higher pre-boil gravity to start with for the given amount of pre-boil wort. You sound like you're doing a lot of things right. Let's see if any Clawhammer users chime in. It does look like a cool system, and not particularly odd or prone to inefficiency.

 

[mr_rogers]

I've never used the clawhammer system before but I have been doing single vessel ebiab for 7ish years.

For me to get my efficiency numbers up I actually reserve a portion of my calculated mash water to use as a rinse.

My process:
raise the strainer basket and let drain, use a pan lid or some other device to put pressure on the top of the grain bed to help squeeze more wort out. pour reserved water (heated up to 170) over the grain bed. then repeat the squeeze process. This has worked for me. I have been planning to add a recirculating element to my rig, in the hopes that it would increase efficiency, maybe not though?

 

[Gbabcock17]

I currently am shooting to end my mash at 5 gallons of wort once the grain is pulled and then rinsing the grains with a gallon of reserve water since I lose about a gallon in the boil. For me this seemed the easiest to track my gravity throughout the brew day because if I measure an OG before the grain rinse it should return to about the same gravity after the boil...Are you suggesting attempting to end my mash with a lower volume of higher concentrated wort, say 3 gallons, so that I can rinse with a higher volume (3 gallons so I have a preboil volume of 6 gallons) of reserve water? Would 3 gallons of sparge water pull more sugar out of the grains than my current 1 gallon sparge?

 

[mr_rogers]

From what you just said it sounds like you do the same process as me. I start my boil with 6.5 gallons and end with 5.25 in the fermentor. you definitely want more than 3 gallons to fully saturate your mash. my mash water volume is usually around 6 or so gallons, I lose some to the grains. then I press and sparge until I am back to 6.5.

let me know if that's confusing. I'm happy to help further. That clawhammer basket looks great btw.

 

[Gbabcock17]

Makes sense! Yes, sounds about exactly like what I'm doing give or take a little on how much sparge water is being used... The single vessel unit with the basket was highly appealing to me. I've had my eye on the clawhammer since I brewed my first batch ever and started saving instantly to get it. So happy to have it in my hands finally. I don't believe my lack of mash efficiency is in anyway related to the brew system itself. Check out thier youtube channel. Some cool recipes and content related to single vessel electric brewing