SG from partial mash "sweet wort"

Last Sunday I brewed an AHS Calif. Common Ale mini mash kit. I found some pretty good partial mash instructions at MoreBeer so I followed them pretty much to the letter. One thing that I missed on was grabbing a sample of the wort after the sparge. I actually did get a sample but I had dumped about a quart or so if plain water in the bottling bucket (mash tun?) and drained it into my brew kettle. The SG for that mix was 1.025. after doing the rest of the full boil I had an OG 1.052 (recipe predicted 1.05 so I think I hit it pretty good).

So here's a couple questions. If I hadn't blown the SG check on the sweet wort would I have been able to obtain what my efficiency was? Since I hit 1.052 for my OG, did I get a pretty decent efficiency out of my mini mash process?

The brew day went really well and I used my homemade immersion chiller for the first time (212° to 70° in just under 15 minutes). Today, she's a bubbling away in the corner

What's up Larry, just bumping your thread as I don't know. I think there is a way to do this if you know the measured amount of wort you had after the sparge. I'm no good w/ math, but fill in the "X" and a math person can likely help you.

You had X gallons of wort after you dumped in the quart of water where you got your reading of 1.025.

If I knew math, it would be something like X-1qt*1.025 or something like that to give you your SG before your addition of 1 quart of water.

Good luck, lets brew sometime!

Hey phatuna, thanks for the bump! I can do math but I'm not worth a hoot at deriving formulas so I'm hoping one of the beer professors will throw in a post.

I like the offer to get together & brew some time, none of my buddies brew so I pretty much do it solo. Maybe after I get caught up on some of the home chores we can find a time that works out

Sounds good, I brew w/ a friend in University City off of the 52 and Genesee. We brew 10 gallon batches about every other weekend. I'll PM you when we brew next, probably not this weekend as we are working on moving away from propane and tapping the nat. gas line. Still trying to rig that up.
-Ryan

LarryC said:

Last Sunday I brewed an AHS Calif. Common Ale mini mash kit. I found some pretty good partial mash instructions at MoreBeer so I followed them pretty much to the letter.

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You do know AHS provides detailed instructions on their MiniMash and Extract kits? (Haven't gotten my first AG in the mail yet...so I don't know if they do it for AG as well)

Is there a different, 'better', or 'easier' way to make MiniMash kits other than the provided instructions?

I mean...the directions aren't that intense either... pretty basic stuff.
1) Steep
2) Sparge
3) Boil
4) Chill
5) Wait a few weeks
6) Bottle/Keg
7)
8) :cross:

If you know the volume of wort you collected from your mash before you diluted it you could calculate your efficiency, or at least get a pretty good ballpark estimate. Say, for example, you collected 2 gallons of wort, and then added 1 qt of water to it. 1 qt is 1/8th or 12.5% of 2 gallons.

so, if that 2.25 gallons had a gravity of 1.025 (25 points), the gravity of the original 2 gallons would be

25 x 1.125 = 28.125, or 1.028.

Make sense? You just need to figure out the percentage that you diluted it. So if you originally had 3 gallons (12 qt), it would be 1/12, or 8.33%. And you would multiply the gravity points by 1.083.

Then just use that gravity and the volume of whatever you collected before diluting it and plug it in to one of those online efficiency calculators. That should at least give you an idea of where you're at.

At least, I think so

Do the kit instructions tell you what efficiency they used to calculate their projected OG?

LarryC said:

I actually did get a sample but I had dumped about a quart or so if plain water in the bottling bucket (mash tun?)...

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I guess you're unsure as to what a mash tun is? If you were collecting your wort in a bottling bucket, that is not your mash tun. Your mash tun is actually where you are conducting your mash - where the grain sits in the hot water to convert the starches to sugars.

A lauter tun is where the wort is separated from the grain and also where sparging is done. In a commercial brewery these are two separate vessels. For homebrewers, they are usually the same vessel. Hence the name "Mash/Lauter Tun" or "MLT."

If i misunderstood your mini-question, well, perhaps that will clear things up for some other new brewer

mc_eric said:

so, if that 2.25 gallons had a gravity of 1.025 (25 points), the gravity of the original 2 gallons would be

25 x 1.125 = 28.125, or 1.028.

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For what it's worth, you don't even need to do this calculation. All you need to know is how much wort you have when you take the gravity reading. Points is points, and you can calculate your efficiency the same whether you have 25 points in 2 gallons or in 5 (as long as the volume difference is plain water, fully-mixed in).

If you've got 25 points in 2.25 gallons, you've got 56.25 points per gallon. Divide that by your potential extract, and you've got your efficiency.

It's also really easy to ballpark it if you know what efficiency was used to calculate the expected OG. If it was 70%, than you immediately know you got at least 70% since your OG was higher (assuming any top off water was mixed in thoroughly).

mojotele said:

Do the kit instructions tell you what efficiency they used to calculate their projected OG?

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The kit instructions I've received from AHS do not mention efficiency, but I think I've seen on HBT somewhere about AHS at 75%. Can anyone confirm this?

Thanks for all the feedback folks. I had thought about the fact that my OG was very close (slightly higher) to AHS's predicted value and that should mean I had pretty good efficiency. I looked through the recipe/instructions that came with the kit and I didn't see any numbers for that but I might have missed it.

mojotele - thanks for the clarification on the mash tun & lauter tun - one of the days I'll have all the terms straight in my head.

ecojack - to your point about the instructions on doing a partial mash that came with the kit. They were adequate but for somebody who had never done it before, there were a lot of unknowns (to me anyway). The info on the MoreBeer site spelled it out in a much more step by step manner. Also, the way they had me do the sparge would seem to be much more efficient (and I think closer to an AG method) than the instructions from AHS.

phatuna - great idea on the natural gas line for your cooker. I think I was down to about 15 minutes of propane left when I finished my brew last weekend - pretty hard to run out when it comes from SDG&E

In the end, it is all good - my wort is still bubbling away and if I can hit the anticipated FG I'll consider it a home run.

Thanks all!

Well done!