mash efficiency vs mash volume

[Sinan]

Using BIAB method, and thinking about mashing grains for 5 gal batch in 4 gal mash volume (instead of buying a new kettle for 5 gal batch) My intuition is telling me that mash efficiency should decrease with increasing grain-to-mash-volume ratio (unless mash time is increased). Wondering if anyone have done this or could point me to a reference. I've done a quick internet search and also quickly checked out Palmer's book but found no quick answers yet. Also, It seems BrewersFriend receipe builder doesn't account for this.

 

[Sinan]

I might have just found the answer I was looking for: subsection 'water-to-grist ration' in chapter 16: "How the mash works" in book "How to Brew" by J Palmer 4th edition:

"....changes in water-to-grist ratios across the range of 2 to 4 L per kg (1-2qt/lb) have only a small effect on fermentability and yield."

I've just calculated water-to-grist ratio for a saison recipe, and it turns out the ratio is 3.78L/kg which is within the above mentioned range. So, I guess I will do just fine!

 

[Hawkbox]

Yeah I think you’ll be fine.

 

[Sinan]

It is interesting to calculate maximum amount of grains "allowed" for a 4 gal mash vol (in a 5 gal pot) for which mash efficiency will remain in the normal range noted in Palmer's book. Higher end of this range corresponds to 2L/kg ( about 1qt/lb). Hence 7.5 kg ( about 16 lb) can be mashed in a 5 gal kettle (assuming grains + water won't exceed the volume limit of the kettle).

 

[Bubba Wade]

What does increase efficiency using BIAB is a modified sparge. For 3.5 gallons of wort, I’ll mash with about 2.5 gallons of water. I’ll pull the bag and put it in a bucket. I’ll add a bit over a gallon of hot water, between 100 and 165 degrees. Temperature doesn’t matter that much as all I’m trying to achieve is a good rinse. I’ll stir the grain and water a bit and then lift the bag and drain into the bucket. The “sparged” wort then goes back in the kettle.

This method takes me from the 65-75% brew house efficiency to 75-78%. There is still a lot of sugar sticking to the grains when the bag is pulled and this helps recover them.

 

[RoadRoach]

I just did a Leffe Abbey Blonde knockoff a few days ago, all grain. Didn't have a big enough bag for the 13+ pounds (nearly 6Kg) so just went wet mash in my 8 Gallon brew pot with a torpedo strainer on the bottom tap. I didn't really notice that much more trub in the wort (the grains did most of their own straining), so rather than having a bag to clean too, I think I"m leaning toward this method for all mashing in the future. No lauter really needed, no need for multiple handlings of hot mash/wort. Capture the wort in a fermenter bucket, rinse the pot, remove the torpedo screen (because hop bags tend to get caught on it), return the wort to the pot, and start boiling. Less gear to clean up. Wort temperature was still 150+ degrees, plenty hot to avoid germs, not to mention, I'm gonna boil it again anyway, right?

Recipe said 1.25Q water per pound of grain. That's 4+ gallons. Then went on to say to heat 5 more gallons to 165 for the sparge while the grain was mashing. I have another 10 gallon aluminum pot (my first brew pot), so large water volume really isn't a problem. Wait a minute, how am I gonna get 9 gallons of water into an 8 gallon stainless brew pot complete with valve and thermometer for reduction, let alone into 6 gallon fermenters? No real big deal for cleanliness, as the boil comes after mash, thus the pasteurizing and sanitizing, so I wasn't too concerned about splitting the sparge between two fermenter buckets, blending the two buckets, then a long slow boil for reduction. I only have the one brew pot (should I get another for a lauter?). I used a LOT of propane on that batch. Obviously, I got several hot-breaks while doing this, too, but it truly turned out to be some amazing tasting wort with a 1.062 out of 1.068 OG. (Everyone tastes through the process like me, right?) I probably could have raised the OG more (and should have) with some more reduction, but was at this point, VERY tired of the process. I'd been at it for nearly 8 hours. Water doesn't flash off very well in the sunny south where a dry day is still 50% humidity.

Lesson learned, one might need to tweak the water use in the recipe. I knew I was making a 5 gallon batch, and about all I got out of the last two gallons of sparge was color. Tasted the wort from the last gallon before blending, and it had very little flavor, and I figure most of the color came with the initial mash, too. Could easily have stopped at 3 gallons of sparge, and only had about a gallon of reduction (a lot less propane) and a lot sooner to the fermenter. Maybe the recipe meant 5 quarts instead of 5 gallons. That would have put me just over 5 gallons of wort, and I could hit it with a few more quarts to cover boiling losses. I did a double, triple, and quadruple check on what it said, though.

Moral of the story, read the recipes several times to make SURE what you're reading makes sense, and ask someone before you blindly follow it. I wound up with a huge mass of yeast on top of my fermenter because I put too much in the bucket. I'm already smart enough to put the buckets in secondary containment in event of a blow-off through the lock. A little clean up (and relieved the pressure) a clean airlock, and back to bubblin'. If it hadn't been exposed to air, I probably would have had a really nice clean yeast culture had I captured it with a blow-off rig. I thought it was just kraussen foam at first, but when I went to clean it up, it was a VERY thick paste nearly 3/4" thick around the air-lock. Just hoping nothing went in as all that was coming out. Guess I'll know when I rack it in about 2 weeks.

 

[BarbarianBrewer]

Sounds like you learn a ton of lessons that brew day! That is quite a few steps you had there. It certainly would be nice to eliminate some of them. Something to consider is brew less volume at a higher strength beer. Then top off with water in the fermenter to reach your desired OG or volume or both. Use the Dilution & Boil off calculator to determine....

1. How much water to add to reach desired gravity (if targeting OG)
2. What your gravity will be if you add a specific amount of water (if targeting fermenter volume)

And don't worry about an infection creeping in while you were cleaning up the blow-off mess. During fermentation the outflow of CO2, especially during active fermentation, would keep bacteria and whatnot from getting in.

 

[Sinan]

Something to consider is brew less volume at a higher strength beer. Then top off with water in the fermenter ...

Just in case, it might be worth mentioning here that hop utilization needs to be taken into account if boil volume is less than the recipe is asking for. Brewersfriend recipe calculator seems to be doing this automatically. @BarbarianBrewer please correct me if I'm wrong here. One gotcha about small vol boil is one needs to add a bit more hops to achieve the same IBU requested in the recipe, hence this might be a minor issue if one has precisely measured ingredients at hand but not more.

 

[BarbarianBrewer]

With the caveat that I haven't topped off with a significant volume of water since I was brewing extract kits so, they had the post-top-off hop part already figured out. Here's where I start to guess so hopefully others will show you why you shouldn't listen to people who are just guessing . I think you could use the IBU Calculator to see how much your IBUs would be before and after topping off. Use that delta to increase your hops. I'm assuming aroma in hops would dilute at the same ratio as IBUs. Playing around with the IBU Calculator it appears that, not surprisingly that if you add 3 gallons of water to 3 gallons of wort, the IBUs drop by half. One last piece of advice is that close counts in Horseshoes, Hand Grenades, Nuclear War and .....IBUs! Get close in one batch and get closer in the next.

 

[Sinan]

yep, the above ibu calculator seems to be doing the job in terms of utilization calculation.

 

[RoadRoach]

And don't worry about an infection creeping in while you were cleaning up the blow-off mess. During fermentation the outflow of CO2, especially during active fermentation, would keep bacteria and whatnot from getting in.

Yeah, there was a bit of pressure built up. Some very lovely aromas came out when I pulled the plugged up air-lock. All in all, though, it was a pretty minor blow-off, and not nearly as bad as I expected, knowing I had WAY too much liquid in the fermenter. I normally do come from the other direction, but followed this recipe word for word, and wound up having to reduce the liquid quantity by boiling. I finally gave up when I got it down to about 6.5 gallons, and probably gave up a few points on the OG by not being able to use all the wort. The expected was 1.068, the actual was 1.064. Another hour of boiling probably would have done the trick. It's certainly the longest boil I've done yet. The mash was super thick, almost like a bowl of oatmeal thick. I think I got overzealous trying to sparge too much sugar out of it, but never strayed from the recipe. The whole time I was thinking, "That's a LOT of liquid."

One of my main curiosities, and I haven't read enough about it yet, is let's say I do a Leffe Abbey Ale, then want to do a Rapier Wit with a repitch from the Leffe. Is it bad juju to change beer/ale type/flavor even if both recipes use the same yeast? I see the WLP-400 used in a LOT of recipes, but the type/style/flavor may be VERY different from one to the next. Does the yeast really care what it fed on last time? Had I known about this repitching thing earlier, I'd have already tried with the dry yeasts I've used. I've heard some good things about the qualities of repitch and doing starters, as long as it's kept sanitary. Not worried about the cost so much as just wanting to experiment with my techniques and procedures. I've got about 25 batches behind me now, so time to start learning more. Some of those dry yeasts had GREAT flavors in the Rapier Wit. But the Rapier uses EXACTLY the same liquid yeast as the Leffe. I've not done a re-hydrate and then culture on a dry yeast yet. How well does that work for making starters? It may be a struggle for me to get space in the fridge for my slurries and starters. The only fridge we have at the moment is in the missus' kitchen. I always get in the last two words with her, though. "Yes dear".

Can I make enough starter from one yeast pack to double-down and make enough to pitch for two 5 gallon batches? Just looking for the cleanest least amount of trouble for repitch. The prep, sanitizing, and cleanup work is 90% of the labor in making home brew. Otherwise, most of it's staring at a Kettle waiting for it to boil. How much of the cake should I recover? It's typically about 1" to 1.5" deep in the fermenter bucket when I rack off to the bottling bucket. Would that be enough to make two starters and then save one for another batch when I free up a fermenter bucket? I've got about 250 bottles now from collecting as well as buying, and it wouldn't hurt my feelings to have every one of them happy on the shelf.

I usually strain my wort to the fermenter through muslin if I pour while it's still hot. That gets out a lot of the chunky bits from hops, grain husks, cracked malt grain, etc. but I've been advised by Kim at AlaBrew (who just so happens to be some kinda certified beer judge as well) that I'm stealing flavors and character from my beer by not letting it stay in. So, I've switched to cooling in the kettle and aerating while I pour it to the fermenter, and then just wash the cake out for grass fertilizer. I let the screens take care of anything larger than a Buick Electra 225. I seem to be getting much faster kick-off for fermentation by not straining to and cooling in the fermenter. But, it's also getting to be a little bit warmer weather and maybe I'm just paying closer attention, too.

 

[Josh Hughes]

I’ve not noticed flavor carry over with slurry unless there was a lot of hops. Sanitize a jar and pour it in. You won’t need all of it. Pitch what you don’t need if you are out of space. The calculator on here has always been good to me in slurry. If you still have beer one in the fermenter then it’s easier. Pour half of the yeast slurry in the jar and it will be plenty unless the second beer is MUCH higher in gravity. Starters and rehydration of dry yeasts isn’t really needed. All of the slurry from a fermentation for me gets me 3-4 more ales on jut pitching what I collected. This is using the calculator on the recipe builder

 

[Bubba Wade]

One of my main curiosities, and I haven't read enough about it yet, is let's say I do a Leffe Abbey Ale, then want to do a Rapier Wit with a repitch from the Leffe. Is it bad juju to change beer/ale type/flavor even if both recipes use the same yeast? I see the WLP-400 used in a LOT of recipes, but the type/style/flavor may be VERY different from one to the next. Does the yeast really care what it fed on last time? Had I known about this repitching thing earlier, I'd have already tried with the dry yeasts I've used. I've heard some good things about the qualities of repitch and doing starters, as long as it's kept sanitary. Not worried about the cost so much as just wanting to experiment with my techniques and procedures. I've got about 25 batches behind me now, so time to start learning more. Some of those dry yeasts had GREAT flavors in the Rapier Wit. But the Rapier uses EXACTLY the same liquid yeast as the Leffe. I've not done a re-hydrate and then culture on a dry yeast yet. How well does that work for making starters? It may be a struggle for me to get space in the fridge for my slurries and starters. The only fridge we have at the moment is in the missus' kitchen. I always get in the last two words with her, though. "Yes dear".

Can I make enough starter from one yeast pack to double-down and make enough to pitch for two 5 gallon batches? Just looking for the cleanest least amount of trouble for repitch. The prep, sanitizing, and cleanup work is 90% of the labor in making home brew. Otherwise, most of it's staring at a Kettle waiting for it to boil. How much of the cake should I recover? It's typically about 1" to 1.5" deep in the fermenter bucket when I rack off to the bottling bucket. Would that be enough to make two starters and then save one for another batch when I free up a fermenter bucket? I've got about 250 bottles now from collecting as well as buying,
.

My strategy for using one packet of yeast for many beers is the build up a large volume of starter and split into multiple containers. Refrigerate the extras. Doing this eliminates worries over style flavors crossing over. I think it also provides less chance of contamination

 

[BarbarianBrewer]

My strategy is similar to @Bubba Wade's. I mostly use liquid yeast and when building a starter, I overbuild it by 30-40%. I pour off roughly a 1/3 of the starter into a sterilized mason jar and pop that in the refrigerator. Next brew I repeat the same process.

 

[Donoroto]

Is it bad juju to change beer/ale type/flavor even if both recipes use the same yeast?
<snip>
Can I make enough starter from one yeast pack to double-down and make enough to pitch for two 5 gallon batches?
<snip>
I let the screens take care of anything larger than a Buick Electra 225.

Nope, do it all the time. Sone may argue the yeast is 'used to' a certain beer, and that may be true, but in several hours new yeasties are born and won't remember.

Yes, you can double your yeast (or more) with a starter. Or use a 5 gallon 'starter'...

My first car was an Electra 225. 12 Mpg and still couldn't get out of its own way.

 

[RoadRoach]

If you still have beer one in the fermenter then it’s easier. Pour half of the yeast slurry in the jar and it will be plenty unless the second beer is MUCH higher in gravity. Starters and rehydration of dry yeasts isn’t really needed. All of the slurry from a fermentation for me gets me 3-4 more ales on jut pitching what I collected. This is using the calculator on the recipe builder

Trying to align the dots on the last half of your reply. Are you saying that if I have just drained a beer from a fermenter, that it's OK to collect part of the yeast/slurry/trub from the fermenter, then just pour a fresh cooled wort on top of the remaining slurry and aerate it? That would be a huge time saver, (if I coordinate my brewing with bottling) but concerns me quite a bit about any krausen stuck in the fermenter. OR, are you saying, take some of the slurry, put it in a CLEAN sanitary fermenter, then put my cooled wort into that? That would still be somewhat quicker, especially if I was making another batch of the same beer. But if the trub has chunky bits (let's say I just made an oatmeal stout), I'm not sure it would be a good idea to try to put that into a pale without some washing/rinsing to get rid of most of the goo from the grains that stay in the wort. Oatmeal stout is one of my faves, but a bit involved for brewing, even as an extract brew. Not much fun to clean up, either. The krausen turns into concrete on the sides of the bucket shortly after opening the fermenter. I normally wind up soaking the fermenter with 5 gallons of hot water just to clean up the bucket again without scratching it. I'm just not as familiar as I've only been doing this about a year, now. Just want to make sure I don't waste some money and a whole lotta time and really screw up a beer that I would otherwise have enjoyed. I don't mind doing things the hard way first for the learning process, so that I better understand any "unnecessary" steps that are taken out. The hard way is a good teacher in the school of hard knocks.

There are a lot of calculators on this site. All I need to do is take the time to learn and use them. Just joined, so gonna have a look around first and check out everything before I jump completely off the path I was on. I'm open to ideas, but I'm also of the old-school thinking that "if it ain't broke, don't fix it." I've been following recipes by rote, so figure it's time to start experimenting a little. Maybe make a recipe of my own somewhere along the line, but the basics are going to be there regardless of the flavorings/adjuncts added. And the basics are what I want to be perfect before I start messing up expensive grains/flavorings.

 

[Josh Hughes]

Yes you can pour fresh wort right in the left over cake. You will have extra stuff but plenty of yeast, an over pitch really. If the beer coming off tastes good then the yeast is fine. The calculator is in the yeast part of the recipe builder. Change it to slurry and go from there. But sanitize a large mason jar. Pour it in. Let it settle, pour off most of the beer and pitch what you need. Day of racking beer of the yeast it’s ready to rock already. If not put in the fridge and use what you need.

 

[BarbarianBrewer]

There are a lot of calculators on this site. All I need to do is take the time to learn and use them. Just joined, so gonna have a look around first and check out everything before I jump completely off the path I was on. I'm open to ideas, but I'm also of the old-school thinking that "if it ain't broke, don't fix it." I've been following recipes by rote, so figure it's time to start experimenting a little. Maybe make a recipe of my own somewhere along the line, but the basics are going to be there regardless of the flavorings/adjuncts added. And the basics are what I want to be perfect before I start messing up expensive grains/flavorings.

@RoadRoach, this is the perfect way to way to learn!

 

[Donoroto]

Trying to align the dots on the last half of your reply. Are you saying that if I have just drained a beer from a fermenter, that it's OK to collect part of the yeast/slurry/trub from the fermenter, then just pour a fresh cooled wort on top of the remaining slurry and aerate it?
OR, are you saying, take some of the slurry, put it in a CLEAN sanitary fermenter, then put my cooled wort into that?

Yes to both. Depends on your preference and timing. Or a mason jar as Josh mentions.

 

[RoadRoach]

Ok, so now I see a procedural change in my future.....

On bottling day, make that also a brew day, and get a wort ready to go back in. Leave it hot until after I rack off the fermented beer, then chill it and transfer some of the cake and the new wort to a cleaned and sanitized fermenter.

That'll make for a long busy day since I still bottle, but not so bad if the missus helps me with the bottling. We can knock out bottling a 5 gallon batch together in about 15 minutes to a half hour. I pour, she caps and marks and puts them in the storage boxes. That's just about enough time to get a wort to start a hops boil. Efficiency is the name of the game on anything that cannot be hurried.