Pain in the Eis- Overshot OG by a country mile

[Marc]

Hey all, I don't post much, mostly just absorb the wisdom here , so this may be more appropriate for the beginners forum, but anyway, here's my deal.

I brewed yesterday what would be considered probably closest to an Eisbock, although I'm using San Fran lager yeast so I can ferment in a cool, but stable room in the house at around 50F ambient.

I came up with a PM recipe, for a 2.5 gallon batch, so I can mash in my 5 gallon kettle. My fermentables were as follows:

2 lbs Munich 20
1 lb Victory
1 lb Vienna
1 lb Crystal 60
3.3 LME Munich
Calculated OG: 1.098

I was shooting for a 155F mash, but had some temp fall off, and during the middle of the mash saw a temp as low as 145. I added some gentle heat, which I know isn't always advisable, but I'm open to experimentation (giggity) and I'm mashing on an induction cooktop, plus I put a vegetable steaming basket in the bottom of my kettle, so I think I'm safe as far as scorching goes.

I mashed 1.5 qts/lb and did a single batch sparge in my old 5 gal fermenter bucket with hot tap water ~115F to get 3.5 gallons of wort. Ok, I sparged too much because this enginerd sucks at math and ended up with about 4 gallons. No big deal, I boiled an extra half hour before my first hop addition.

Boiled down to 2.5 gallons in another hour, as planned. Chill with a coil chiller to 60F. I used a sanitized cup sized liquid measure to take a sample for my gravity reading, put in in the test cylinder with the hydrometer and left it to de-bubble a little while I transferred to my fermenter and pitched my yeast starter.

I was shooting for about 1.098, using the brewersfriend.com calculator and 80% brewhouse efficiency. Aaaand somehow, I ended up with a reading of 1.116! Ok, more booze in this style not necessarily a deal breaker anyway, and the yeast should be able to handle it, fingers crossed.

But still, how was I so far off? I didn't weigh my grains ahead of time, so it's possibly my home brew store was over on a measure. But what else could've given me such a high reading? Did my low temp mash have an effect? Should I have stirred the post boil wort before taking my sample? You'd think if anything, an unstirred post boil wort would stratify with higher gravity liquid at the bottom, not the top. If everything matched the nominal numbers, that OG gives me a kettle efficiency of like, high 90s, which I don't think is likely.

Even stranger because my last BIAB pm brew was a middle high gravity IPA (OG 1.076) which I hit exactly, using the same calculator and only a 75% brewhouse efficiency. Just bottled that yesterday and the FG was perfectly on the money as well.

Gonna have to go back to 12 oz bottles for this faux-eisbock I think

 

[str1p3s]

My two thoughts:

1) Check your hydrometer with water to make sure it's calibrated
2) You said you boiled down to 2.5 gallons, but with shrinkage after it cooled, it should be less than 2.5 gallons. So maybe you concentrated the wort more than you thought?

 

[Marc]

Thanks str1p3s. Hydrometer is good. I did check it about a year ago, but I can't think it'd change unless I dropped it and chipped the lead or glass, which I haven't. You're right on point 2 that it definitely would get denser after cooling which I didn't think of, but I was a little over 2.5 at the end of boil anyhow. I can't imagine it would account for 18 points on its own, anyhow.

Another stupid but possibly related question- the PPG rating on LME accounts for its water content right? IOW, if you add 1 lb of LME to water the PPG tells you what gravity you should have with a gallon total solution right? Not if you add 1 lb to a gallon of water (where you'd end up with a gallon plus wort)? Because I added my LME to my mash wort before I sparged so I could see what I'd need to end up with my total goal pre boil volume and not pre boil volume plus whatever 3.3 lbs of LME adds.

 

[doug293cz]

Thanks str1p3s. Hydrometer is good. I did check it about a year ago, but I can't think it'd change unless I dropped it and chipped the lead or glass, which I haven't. You're right on point 2 that it definitely would get denser after cooling which I didn't think of, but I was a little over 2.5 at the end of boil anyhow. I can't imagine it would account for 18 points on its own, anyhow.

Another stupid but possibly related question- the PPG rating on LME accounts for its water content right? Yes IOW, if you add 1 lb of LME to water the PPG tells you what gravity you should have with a gallon total solution right? Correct Not if you add 1 lb to a gallon of water (where you'd end up with a gallon plus wort)? Because I added my LME to my mash wort before I sparged so I could see what I'd need to end up with my total goal pre boil volume and not pre boil volume plus whatever 3.3 lbs of LME adds.

Brew on