boil times?

[brewskiez]

I'm doing a couple bigger brews this weekend and doing them biab. I've had trouble in the past getting the sg right im usually pretty short as in my final abv calc is usually 2-3 % low. I was thinking maybe to the full biab and then sparging a few more gallons of hot near boiling water to get more sugars off then just boil longer until I get to the final volume. I don't fully understand what a longer boil would do to my wort if anything.

 

[madscientist451]

If you add more water (sparge) and then boil longer and evaporate off the amount of extra water you added, will you have higher gravity?
There's a lot of variables involved in that scenario, so its hard to say for sure, but I'll take a chance and say probably not.
With BIAB, the easiest thing to do is to adjust your grain bill to bring up your gravity.. Since you are only off by 2-3%, just add base malt.
Your other option is to keep the recipe the same but reduce the volume;
but who wants less beer?

 

[brewskiez]

I don’t know if we’re on the same page. I meant I believe I’m not getting enough sugars off grain by just squeezing the bag so I’d like to try to knock all I could off the grains by washing grains with extra hot water and then boil that extra water off later.

 

[RM-MN]

I don’t know if we’re on the same page. I meant I believe I’m not getting enough sugars off grain by just squeezing the bag so I’d like to try to knock all I could off the grains by washing grains with extra hot water and then boil that extra water off later.

You could use the hot water for sparging.....or you could use cool water. The biggest difference is in the time to bring the wort to a boil. Your grains will be hot enough to warm the water so that the sugars will dissolve in it almost the same as if you used boiling water. If you have been BIAB full volume and coming up short on the OG, sparging will help you. The extra water will rinse the sugars but the concentration of the sugars in the wort will be lower so you boil off some of that extra water to concentrate the sugars, raising the OG.

If you had been sparging and still getting a lower than expected OG you have two choices. Add more base malt to make up for poorer than expected efficiency or get your own mill and mill the grains finer to be able to get higher conversion.

 

[myndflyte]

As others have alluded to, I don't think using extra water in the mash and sparge is going to help you. You're best advise is to calculate your efficiency from your last brews and use more base malt to compensate for it. Or get a finer crush.

Or you could have some DME on hand, take a pre-boil gravity reading and use this calculation to determine how much DME to add:

(TOG - GR * (BV/FV)) / (45/FV) = lbs of DME to add pre-boil to hit target OG
TOG = Target Original Gravity in Points
GR = Gravity Reading in Points
BV = Boil Volume (This is what you are taking your reading from)
FV = Final Volume (i.e. 5 gallons)
45 = # Gravity Points you get per lb of DME per gallon

 

[eric19312]

I'm doing a couple bigger brews this weekend and doing them biab. I've had trouble in the past getting the sg right im usually pretty short as in my final abv calc is usually 2-3 % low. I was thinking maybe to the full biab and then sparging a few more gallons of hot near boiling water to get more sugars off then just boil longer until I get to the final volume. I don't fully understand what a longer boil would do to my wort if anything.

These beers that are 2-3% low that is a very different problem than if you were aiming at 5% ABV vs if you were aiming at 10% ABV. Would help to understand what your SG targets were and what you were getting. What was your expected efficiency and what was your actual efficiency?

If you are actually getting 65% efficiency I'd agree with @madscientist451 and increase your grain bill. You can do that at same time you try to tweak your technique by adding a small sparge or perhaps crushing finer. A little luck and the change helps and you improve to 75% efficiency and slightly overshoot your SG target, less luck and the change doesn't help and you still come in at target SG.

But if you are actually getting 45% efficiency I'd focus on process and not try to fix this with increasing your grain bill. If you are at 45% there is surely easy things to do to gain substantial efficiency bump.

 

[chris000]

the joy of BIAB is it's a simple all grain process. and the simple answer would be to adjust your grain bill to match the efficiency.
but as eric wrote, if you are way off, you have to fix the process first!
before you go for a sparge, check ground, re-circulation/stirring, bag size (big enough for sufficient water-grist ratio)

 

[brewskiez]

It’s been a while since I’ve done a 9 brew maybe I’ve been a little gun shy will see how it goes I’m doing a ris. Will increasing boil time mess with the recipe

 

[myndflyte]

It’s been a while since I’ve done a 9 brew maybe I’ve been a little gun shy will see how it goes I’m doing a ris. Will increasing boil time mess with the recipe

Not necessarily if you stick to the hop schedule. You're really just wasting time though. Why not just spend a few extra dollars in grain, mash and sparge normally and just boil for 60 min, instead of sparging with more water (which may not even increase your efficiency anyway) and then waste time and boil longer?

 

[dmtaylor]

I'm doing a couple bigger brews this weekend and doing them biab. I've had trouble in the past getting the sg right im usually pretty short as in my final abv calc is usually 2-3 % low. I was thinking maybe to the full biab and then sparging a few more gallons of hot near boiling water to get more sugars off then just boil longer until I get to the final volume. I don't fully understand what a longer boil would do to my wort if anything.

Sounds like a good plan to me. When I target a big gravity beer like something I want around 1.100, I do the same thing -- sparge more and boil maybe 2 hours instead of just 1 hour. Efficiency stays up in the mid-70s when I do that. Otherwise it would fall like a rock and I'd either have to add extra malt or extract, or take the hit and not reach my gravity goal. Your plan is a good one.

 

[dmtaylor]

It’s been a while since I’ve done a 9 brew maybe I’ve been a little gun shy will see how it goes I’m doing a ris. Will increasing boil time mess with the recipe

Oh yeah... if you are brewing a RIS, then definitely sparge and plan for like a 2-hour boil. It won't hurt a flea; it will only help.

Cheers and good luck.

 

[brewskiez]

Everything turned out good probably . I got 1.095 for the sg however I didn’t take temperature so it doesn’t really mean to much but I stirred the stuffing out of the mash a couple times through the time it was sitting. I think that helped a lot not to mention I used two lbs of malt extract to sub in for two lbs of grain making it a little less crowded in the mash pot. I let the boiled wort sit on my wort chiller for quite a while I’d imagine the wort was around 65 degrees +- 5 when I took sg but I’m just guessing.