Beersmith 2 Question

[eeverwine]

Ok so maybe some of you have a lot more experience with this.

I recently completed my second all-grain brew on Friday, a Nut Brown Ale. The day went perfectly except in one aspect. We wanted to make more of a session ale with this one, and according to Beersmith my target OG should have been around 1.050. When we finished the boil we ended up with around 1.060, can't remember the exact number cause I'm at work.

I realized that Beersmith was set to the default brewhouse efficiency of 72%. On our first brew we hit around 78% efficiency, and this time we hit 83%. We had a finer crush and a slower fly sparge which I assume is what gave us our higher numbers this time. I'm using the 10 gallon northern brewer all-grain system with round coolers and a false bottom.

I guess my question is, how many beers do you have to make before you know your average efficiency? I'd like to hit my target OG every time as we really want to make a lower ABV beer one of these days. Can't seem to get under 6% ABV haha

 

[gr8shandini]

It took me 5 or 6 batches to really get dialed in, and even so, I still occasionally miss my pre-boil numbers by a few points here or there. Usually it's when I change malts. I've found that I take about a 5% hit in efficiency when using Marris Otter or a high percentage of wheat or rye.

For me, what matters more than the efficiency number is being able to adjust your boil-off to get the right OG.

 

[PoppinCaps]

Efficiency depends on a number of factors, and the more you keep them constant, the more you can predict your efficiency. I think the main ones are grain crush and your lauter process. If you stay within 10 pts every brew, you can easily hit your expected OG. The bigger the beer, though, the lower your efficiency will be, but by how much depends on your system. I'd say a round number of 3 beers, roughly the same recipe and keep the crush and process the same (same mash volume, sparge volume, lauter time, etc), you should be able to see a solid trend.

 

[eeverwine]

Thanks for the responses. The boil-off thing is interesting. We measured 8 gallons of wort pre-boil this time and let the sparge keep running after we started the boil, in the remaining bucket we had about 3 more gallons of wort! It was a bit lighter, but still, wow. So when we finished our boil we still had under 5 gallons in the carboy, which means we boiled off more than 3 gallons during an hour. We're using a 20 gallon mega pot as we eventually want to make bigger batches. I've heard with wider bottom pots you boil off more, so we obviously need to figure out our average number there. I need to make a measuring stick for the pot, its starting to seem ridiculous.

Do you think we boiled off too much or should have used the extra collected wort? If we did use the extra three gallons, would our OG have been lower?

 

[fletchsj]

More liquid = generally lower gravity. Obviously as long as that liquid has less sugars in it than the wort in your kettle. Big wide bottom pots generally see more boil off. Although you'll see a difference when you step up to larger batches. Ie 5gal batches will boil off a higher % that 10 gal batches. Atleast from my experience.

 

[eeverwine]

So factoring in my higher rate of boil off and using the mash efficiency numbers I've been getting near 80% should I set beersmith to around that when designing my next recipe? Sorry for the barrage of questions. I figure if I edit the efficiency in beersmith closer to 80% I'll get an OG that I'm more likely to hit