Two AG brews down, same problem

So I did my second AG yesterday. Everything went okay, but it definitely could have gone better. I hit my mash temp right on the dot and it held for the entire 60 minutes. Again I collected ~2gal less wort from the mash than I mashed with. I'm not so much concerned about this after searching some posts on this forum. I have been losing the expected .12-.13qt/lb so that seems to be in line. My issue comes with the collection of my sparge water when batch sparging. I have come up between .5-.7 gal short both times. I've heard you should get pretty much no loss when sparging. I'm wondering if this amount seems reasonable? I still had some hot water left over in the kettle so I just ran ~1gal through it and collected the .5gal I needed. I think I'll just add .5gal to what the brewing software says to use for sparging.

My next problem is with my boil off. I collected 6.5 preboil and once I got a sample cooled down took a reading. It was 1.063 which is only 1 pt lower than it was predicted. After my boil I only collected ~4.9gal so I had to top off to get to my target of 5.5gal going into the fermentor. After chilling that sample I took a reading and it read 1.063. That reading was actually 10pts lower than it should have been and it makes no sense to me how the reading could be the same with less volume. As far as my boil off, the previous batch I maintained a rolling boil but this time it was a bit more vigorous and it was about 104°F out. So I'm thinking that's why I had such a high loss. I went in to my brewing program and increased my boil off rate some since I came up short both times. We'll see if those changes help get it dialed in. If any one has any advice on how I can straighten this out it would be greatly appreciated.

So I did my second AG yesterday. Everything went okay, but it definitely could have gone better. I hit my mash temp right on the dot and it held for the entire 60 minutes. Again I collected ~2gal less wort from the mash than I mashed with. I'm not so much concerned about this after searching some posts on this forum. I have been losing the expected .12-.13qt/lb so that seems to be in line. My issue comes with the collection of my sparge water when batch sparging. I have come up between .5-.7 gal short both times. I've heard you should get pretty much no loss when sparging. I'm wondering if this amount seems reasonable? I still had some hot water left over in the kettle so I just ran ~1gal through it and collected the .5gal I needed. I think I'll just add .5gal to what the brewing software says to use for sparging.

My next problem is with my boil off. I collected 6.5 preboil and once I got a sample cooled down took a reading. It was 1.063 which is only 1 pt lower than it was predicted. After my boil I only collected ~4.9gal so I had to top off to get to my target of 5.5gal going into the fermentor. After chilling that sample I took a reading and it read 1.063. That reading was actually 10pts lower than it should have been and it makes no sense to me how the reading could be the same with less volume. As far as my boil off, the previous batch I maintained a rolling boil but this time it was a bit more vigorous and it was about 104°F out. So I'm thinking that's why I had such a high loss. I went in to my brewing program and increased my boil off rate some since I came up short both times. We'll see if those changes help get it dialed in. If any one has any advice on how I can straighten this out it would be greatly appreciated.

1st Q) If you're hitting your preboil gravities, don't worry so much about volume. If you want more volume, adjust your malt bill and adjust your sparge volume/brewhouse efficiency as necessary.

2nd Q) Think about it. You were 1.063 preboil. Post boil you were X. You diluted it with water so now you're X - Y. X - Y = 1.063. Meaning you *were* at something higher than 1.063 post boil (maybe 1.073?), but you diluted it when you added water to top off to the volume you wanted. You need to figure your target volume and gravity into your recipe before you boil (see above). You can't just add water to adjust volume without it diluting the overall recipe.

It's great that you are taking detailed notes in your process because everything you are doing is easy to fix. The values that you have determined you are losing need to be added into your software as losses in the process, then the software will add those amounts back as part of your mashing in, sparging processes so your final volumes are met. In addition it appears your boil off may be greater than what you currently have listed in your equipment set up. Boil off is tricky because there are differences related to weather, humidity, temperature and vigor of the boil but you should be able to get close enough where it's not a huge deal.

It usually takes several batches of brewing to get a good handle on all the settings required for software and being sure to input all the right values, once done though, the software will do a great job on calculating everything properly!

You probably need to increase the "mashtun deadspace" figure a little in your software.

Bobby_M said:

You probably need to increase the "mashtun deadspace" figure a little in your software.

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Bobby scores again!

I agree with the other posts, you should adjust your mash tun's dead space (I tip my mash tun which helps with dead space loss). Adjust your boil off rate and make sure your batch size is set properly to the amount you want in the fermenter.

As for your second question, one of the readings, and/or your volume measurements were off. Walking through the math, a preboil gravity reading of 1.063 is 409.5 total gravity points (63 * 6.5). Boiling to 4.9 gallons would be a 1.084 reading (409.5/4.9), then topping off to 5.5 gallons and you're at 1.074 (409.5/5.5). I think I did the math correctly...

I hope this helps, as others have mentioned all of this is easily fixable for future batches. Taking detailed notes as you did is key to dialing in your estimates within your brewing software.

I'll also add that over 1.5 gallons of wort loss seems like a lot to me. Was this a 60 minute boil? My boil off rate is around .75 gallons per hour.

Pie_Man said:

I'll also add that over 1.5 gallons of wort loss seems like a lot to me. Was this a 60 minute boil? My boil off rate is around .75 gallons per hour.

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I lose 1.5 gal. an hour easy. Sometimes a bit more.

Sorry, I'm really confused. How does increasing mash tun deadspace in the software change his gravity, efficiency or boil off rate?

Cromwell said:

Sorry, I'm really confused. How does increasing mash tun deadspace in the software change his gravity, efficiency or boil off rate?

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It doesn't, it helps to solve the sparging water volume issue (question 1).

Pie_Man said:

It doesn't, it helps to solve the sparging water volume issue (question 1).

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OH, I see. Thanks for clarifying.

Denny said:

I lose 1.5 gal. an hour easy. Sometimes a bit more.

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Thanks Denny. I thought to mention it as I wasn't sure. Maybe I need to boil more vigorously? Although I get a good roiling boil.

Cromwell said:

Sorry, I'm really confused. How does increasing mash tun deadspace in the software change his gravity, efficiency or boil off rate?

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It changes the efficiency calculation because it accounts for reduced wort volume.

Thanks for all the replies. I increased the dead space measurement by .5gal since that seems to be roughly the amount I'm losing when sparging. Perhaps I'm getting too vigorous a boil going. I just have been reading that I need to make sure I get a good boil to drive off the DMS. I'd definitely say it's a little more than rolling. What are you guy's opinions of this? Either way I increased the boil off rate some to try to account for the loss. As far as the gravity. I definitely could have been off some where. I had a few beers and could have gotten things mixed up. Pie_Man, your math ended up with the post boil SG of 1.074 the recipe estimated. That is part of the reason I was confused. If I pretty much hit my preboil gravity and volume and ended up with 4.9gal instead of 5.5gal afterwards, I would think that topping off to 5.5g would get me at least close to where I wanted to be on the SG. Maybe I'm missing something there. I will be putting some of your suggestions into practice on my next batch and think I'll get some good results. Thanks again.