I’ve been brewing for a while now and have recently made the leap to all grain from extract/partial mash recipes.
I’ve done 4 all grain batches and in all 4 of them my SG has come in around 10-20 pts lower than expected. It’s confusing and frustrating since I’ve never really had to worry about this issue with extracts. I’ll give you a list of my gear and a brief rundown of my process. Any advice would be greatly appreciated.
My mash tun is made from an Igloo Quantum cooler - 55qt capacity with a cpvc manifold.
Heat loss is around 1 degree/hour.
I use the batch sparge method. Drain the mash tun, measure collected volume, figure out grain absorption, add enough sparge water to get to boil volume. I know there’s a lot more depth to it than that, but I’m still a rookie and am going with what I’ve read and seen in some YouTube videos.
Boil kettle is a 10 gallon Amcyl brand.
There’s about a gallon of deadspace below the ball valve that I account for in Beersmith for trub/hop loss.
Thanks in advance for your help. Hopefully I gain some knowledge here that I can then pass on to the next guy who needs a hand.
I have 2 pieces of advice…low efficiency is often (I’d go so far as to say almost always) related to crush. Crush your grain finer. The other thing is that you need to adjust any recipe to your own system efficiency. It could be you’re not using enough grain. Figure out what efficiency you’ve gotten on the batches you’ve done, then adjust the next recipe based on that. Between crushing finer and adjusting the recipe, it should get you where you need to be.
Best to have all your water needs calculated first. And you also need to compensate for grain absorption and add that water to the first sparge. For instance to get 12 pre-boil gallons out of a batch-sparge you’ll dough in with the extra water- say 2 gallons. That would make the first sparge 8 gallons and the second 6 for a total of 14 gallons used.
To me it looks like you are adding the extra water in the second sparge. This could cause all sorts of problems and effect your extraction greatly.
Why is that Euge? I seldom do. Maybe roughly, but I adjust based on reality. I also never add the extra “compensation” water…in reality, if you do it, it’s not compensating for absorption. Originally the idea was to not thin the mash too much, so you’d add extra water later. In the intervening years, I’ve discovered that you can have a much thinner mash than was originally thought, so the right way to go these days is just to mash thinner and skip that addition. It made no difference to my efficiency. In fact, my efficiency went up due to the thinner mash.
Thanks Denny. I’ve been crushing my grains at Northern Brewer since I haven’t purchased my own mill yet. I’ll go a bit finer next time and see how it goes. As far as figuring out efficiency, that’s new to me also. I’ll poke around in Beersmith and see if I can figure out how to do it. I’m sure it will involve me screwing up a few more batches to get it dialed in but I’ll do whatever I have to do!
Euge, you’re right. I’ve been adding the additional water on the second sparge since I’m not sure how much I’m gonig to lose to absorption right away. Is there an approximate value for this? X amount of water absorbed per pound?
Ah, that explains it some. NB is a great place, but they’re notorious for a poor crush. You will lose no water to absorption on your sparge. The grain is already saturated.
1/ Do you crush your own grain? If so, crush finer. Too coarse a crush will cause your efficiency to suffer.
2/ Do you control pH? Well controlled pH will help you get better conversion of starch into fermentable sugar. If you haven’t, download Brunwater to help estimate your pH accurately.
3/ Are you confident in your temp and hydrometer measurements? A thermometer that doesn’t read accurately can have you mashing at a less than optimum mash temp which could affect your OG. When and how do you take gravity readings?
4/ Are you getting your water volumes correct, ie., preboil volume, post boil volume? You can extract the right amount of sugar from the grain but be off on your water volumes which could dilute your OG reading.
Denny I don’t calculate my water grain ratio to include absorption except when doughing in to calculate temp.
I figure that each lauter’s resulting volume should be as equal as possible. According to Ken Schwartz’ equation. So I calculate each plus whatever I’ll lose to the grain.
I helped Ken come up with those figures and in the time since have discovered that equal runnings makes so little difference that it’s not worth the effort to chase it. If your runnings are within a gal. or so it’s close enough. And after the mash, you shouldn’t be losing anything to the grain.
Like said above… Crush your grain about as fine as you can get it. As far as efficiency goes, I would start toying around wit 70-75% as you make your recipes.
First tighten your crush, and if you know your grain bill and strike volume you can determine the conversion efficiency which is closely related to how well the crush and dough in went.
Secondly, make sure you’re stirring your heart out during dough in and the batch sparge.
For water volumes, you can use any software that’s set up correctly. I completely unbiasedly recommend taking a look at my mash calculator, Priceless Brew in a Bag Calculator as it’s very easy to use and will calculate the conversion, lauter, mash, and preboil efficiencies based off of just a few measurements. From there you can usually tell what the issue is (crush vs sparge).
As far as run off ratio goes, as long as they’re somewhat close it’s fine. If you use my calculator, and watch the lauter efficiency, there’s little difference in a ratio of 0.4 and a ratio of 1.0 (equal runnings). For most brews, the difference is ± 1 %…
Same here. For a while I’ve been keeping mash runoff around a gallon more than the sparge runoff. For most beers that ends up ~ 1.75 qts/lb. I like the efficiency bump.
I think we’re all doing the same thing essentially with some variances.
The website I use has “absorption” factored for the mash. It’s not explicit by any means, but the extra water could come in the form of a mashout, which I think Denny was alluding to.
cut the grain after you’ve done your initial pull and before you sparge(slice it like a pie)
use more grain:) sry had to
also, when you think you’ve pulled all the wort off the grain that is there… wait a few… go back and wala… there’s more… and it’s highly concentrated in sugars…
adding a little 6-row or a little higher ph tend to yield better efficiency
how fresh is your grain(this is a big one)… the longer it sits, and in particular if too much moisture gets to it, it loses some of it’s diastitic power… make sure you’re purchasing your grain from a place that turns over a lot of grain…
Another experienced batch-sparger here, but with a slightly different recommendation on your mill settings- pick a setting and stick with it if you can. I’m sure that northern brewer does what makes sense for a retailer to do- have a coarse crush on the store mill so customers don’t complain about stuck sparges! If you can adjust their mill- great! But try and come up with a way to measure the setting (a gap gauge works) so you can repeat the same crush with each batch you crush. This will help you nail down your efficiency so you can adjust any recipe accordingly. Otherwise, you’ll always be futzing around with what pre-boil gravity you have. Consistency in your efficiency is more important than the magnitude of the efficiency- i.e. getting 65% every time is better than getting somewhere between 75 and 90% efficiency on an inconsistent basis.
FWIW I’ve started ripping the malt through first at the widest gap and then again closed as far as it will go. Very consistent uniformly small nits, large husks and minimal flour.
Thanks everyone. Lots of good tips here. I’ll probably start with a finer crush on the grain, really smash the hell out of it and increase my mash water volume slightly to see if that helps. Going to try my hand at this again next weekend so I’ll post the numbers for the recipe and what I actually get.