Brewer's Friend Home Brewing Software

On the relationship between Plato and specific gravity

One of the most important measurements in brewing is the “sugar” content of wort and, later, beer. Sugar is in parenthesis because what is dissolved in wort is more than just sugar. It’s various sugars, proteins, lipids, minerals and trace elements. The professional brewing world refers to this collection of compounds as extract.

There is a strong and very predictable relationship between extract content of wort and its specific gravity. Because of this relationship we brewers can use hydrometers to measure wort extract content. Around the 1900s Karl Balling, Adolf Brix and then Friz Plato established a correlation between the density (specific gravity) and the sugar content of pure sugar. Each measured with more precision that the predecessor.

To make high precision specific gravity measurements, a device called the pyknometer is used. The volume of liquid held in a pyknometer is known at a very high precision and by weighing it empty and with the liquid to be tested, the density of the liquid can be determine very accurately.

The results of these measurements are available in tables in which the density for various sugar concentrations, expressed as weight percentage of sugar, is given. This relationship is only true for a given standard temperature. These sugar weight percentages are also referred to as degree Balling, degree Brix or degree Plato (°P). Essentially they are all the same. Degree Balling is rarely used anymore, degree Brix has been adopted by the wine industry (hence its use in refractometers) and Plato is used by the brewing industry.

Brewers, especially home brewers, commonly use specific gravity (1.xxx) or gravity points to express extract content without first converting to Plato. This is possible since the relationship between sugar content and specific gravity is reasonably linear. It’s also worth noting that the mix of compounds dissolved in wort doesn’t change the specific gravity exactly as pure sugar does. But this is ignored by convention. I.e. a wort with specific gravity X is assumed to have the same extract content as a pure sugar solution with the same specific gravity. In practice there is not much of a difference anyway.

To convert specific gravity to degree Plato the ASBC (American Society of Brewing Chemists) published a polynom that fits the data published in Plato’s tables (1):

A quick and dirty conversion between specific gravity and Plato is Plato = gravity points / 4. This formula works well up to a specific gravity of 1.060 where the error approaches 2%.

The relationship between specific gravity (density) and extract content (Plato) can also be used to calculate the volume increase caused by the dissolved extract. Many brewers don’t know that the volume of wort they produce is actually larger than the volume of water that is added. This is because the sugar increases the total volume of the solution.

Let’s assume 1 liter of water and dissolve 150 g of extract. The resulting wort has 0.15 / (1.00 + 0.15) = 13.04 Plato since Plato is the extract weight as percentage of the combined extract and water weight. A 13.04 Plato wort has a density (specific gravity) of 1.0527. Thus the 1.15 kg wort has a volume of 1.15 / 1.0527 = 1.092 l. This is 0.092 l more than the initial water. In general, each kg of dissolved extract increased the volume by about 0.61 l (0.3 qt for each pound)

This volume increase doesn’t matter much for general brewing calculations. When calculating the amount of water needed this effect leads to lower than actual grain absorption. A case where it does matter is calculating the efficiency of no-sparge or batch sparge lauter efficiency since that is determined by the ratio of the volume collected in the kettle over total volume in the mash.

Most tools, including Brewer’s Friend roll the volume increase from the sugar into the grain absorption factor (so even though it is happening, you don’t have to worry about it).

(1) A.J. DeLange: Specific Gravity Measurement Methods and Applications in Brewing

The following image shows the same hydrometer with the SG (specific gravity) and Brix/Plato scales:

For more articles on the subject of hydrometers:

Hydrometers readings are temperature dependent. All hydrometers are calibrated to a certain temperature – typically (59° F / 15° C) or (68° F / 20° C).  Use this calculator to adjust:
https://www.brewersfriend.com/hydrometer-temp/

Hydrometers are sometimes incorrectly calibrated at the factory, see our article on how to test yours:
https://www.brewersfriend.com/2010/12/19/instrument-calibration-for-maximum-brewing-awesomeness/

Post by Kaiser

Brewer’s Friend would like to welcome Kai of Braukaiser.com as a guest blogger and technical advisor! We’d also like to say thank you to him for his recent input on our October 2012 release, which included Plato support!

Posted in Brewing | 3 Comments »

October Release Is Live – Plato, Efficiency, and Batch Size Upgrades

The October release at Brewer’s Friend is live!  This release targets serious brewers who want accuracy, ease of use, and more rigor in the definition of their recipes and brewing process. We hope you will enjoy tapping into Plato support on the recipe editor, four types of efficiency available in the brew session, and the ability to designate an all grain batch size as ‘to the fermentor’, or ‘to the kettle’.

Brewing in Plato:

Plato is a sugar extract scale commonly used by pro brewers. It also happens to fit very well with metric brewing.  Many breweries choose to list degrees Plato on their beers instead of specific gravity. Now you can work in Plato too!  Look for the option under the More… button on the recipe editor.

By toggling the Sugar Scale option, the recipe automatically converts OG and FG between SG and °P. Specific gravity is still the default, but it can be changed under your brewing profile.  Brew log entries may also be entered in Plato.

See more in the FAQ about Plato support.

Efficiency:

When someone says they got 85% efficiency, that doesn’t mean much to me.  What kind of efficiency and is it reliable?  There are actually four types of efficiency, and Brewer’s Friend calculates each of them:

• Conversion Efficiency – what percentage of sugar was extracted from the grain in the mash.
• Pre-Boil Efficiency – what percentage of sugar made it into the kettle.
• Ending Kettle Efficiency – what percentage of sugar was present at the end of the boil.
• Brew House Efficiency – what percentage of sugar made it into the fermentor.

This release adds new Brew Log event types for tracking each of these inside a Brew Session.

We have lot more to say about efficiency, but it is too much for this post. Please check our FAQs:

• How is efficiency defined on the recipe editor?
• How is efficiency calculated in a Brew Session?

Batch Size:

Like the term efficiency, ‘batch size’ is also ambiguous. Up until this release, batch size meant how much wort is going into the fermentor for all recipe types.  That still makes sense for Extract and Partial Mash recipes, which involve topping off the fermentor with water to hit target volume.  This release does not change how Extract or Partial Mash recipes work.

All Grain and BAIB recipes now have a setting to change the ‘batch size target’ to ‘kettle’.  Ending kettle volume becomes the batch size in that case.   This improves recipe portability because it eliminates variation from trub losses and hops absorption.

There is a twist with supporting multiple batch size targets: since a different volume is being targeted at a different point in the brewing process a different efficiency value needs to be used. When batch size target is set to ‘kettle’, the recipe switches itself to use kettle/lauter efficiency.

All existing recipes have been defaulted to batch size target of ‘fermentor’, and use ‘brew house efficiency’.

The view recipe page indicates which type of batch size and efficiency is being targeted. The water calculation inside the Brew feature is aware of the batch size target and will adjust automatically. The batch size target default is still ‘fermentor’ but you can change that in your profile.

See more in the FAQ about changing the batch size target.

Other upgrades:

• Recipe view page shows total weight of all fermentables for a recipe.
• Hops AA limit increased to 100 to support hop extract.
• Stand alone hydrometer calculator remembers your calibration with a browser cookie.
• All stand alone calculators updated to look better and support metric units!
• Fix to water chemistry calculator – chalk ppm contribution corrected to account for portion that is non-soluble.
• Brew Session’s Mash Calculator section has a new FAQ.
• Brew Session’s Mash Calculator Infuse tab supports lowering temperature with cold water (but not ice).

We’ll follow up with additional blog posts about Plato and efficiency. We also have a spec done for our upcoming yeast calculator!

Post by Larry

Posted in Announcements | 1 Comment »

Draft Beer At Home – Keezer Build With Collar

Close your eyes and imagine your personal in home bar, complete with a draft system, stocked full of home brew!…. Congratulations! You are thinking of a Keezer! Here’s how to build one:

What the heck is a keezer?  Very simply, a keezer is a chest freezer that has been converted into the ultimate refrigerated beer serving chamber!  Keg + Freezer = Keezer.

Why does it have to be “converted”? Chest freezers often lack the height inside to comfortably accommodate 5 gallon cornelius kegs and the associated draft plumbing. There is a hump inside for the compressor that eats up a good amount of floor space. Even more important to note is that these freezers have extensive plumbing running through the walls of the appliance. Do you REALLY want to drill through the wall of a freezer to install a shank and hope that you do not ruin your freezer? Probably not.

The basic process for building your Keezer is to install a wooden collar on top of the keezer (below the lid). That extends the Keezer’s internal height, allowing it to hold more corny kegs, and providing a place for all the taps to go.

This project is fairly easy to accomplish and requires few materials to complete. In one afternoon, you can easily convert an old chest freezer into a keezer, which will reliably cool and serve your homebrew for years to come.

What you will need:

• Tape measure (measure twice, cut once!)
• Circular saw (to cut your lumber to length)
• Lumber (this will vary on the height of the collar you wish to build, 2” x 6” is a good start)
• Power drill (for drilling pilot holes, shank holes and installing screws)
• Wood screws (for building the keezer collar)
• Construction adhesive (to seal the gap between the wooden collar and freezer lid, as well as attach the freezer lid gasket to the keezer collar)
• Hole saw (for drilling holes in collar for the shanks)
• If you don’t already  have one, a temperature controller for your freezer chest to keep the beer at serving temperature (as opposed to freezing it).
• We highly recommend getting a moisture absorption product for placement inside your keezer to avoid condensation and eventual mold build up.

Steps:
#1. Remove the lid from your freezer, this will make measuring and fitting the collar that you are about to build, much easier. You will also want to REMOVE the hinges from the lid, as soon they will be mounted to the collar, allowing the lid and collar to swing up and out of your way when you open the keezer.

#2. Remove the rubber gasket that seals the lid to the freezer when the lid is closed. You will not need it on the lid after building the collar, and you will want to use this on the base of the collar, or the ledge of the freezer, to properly seal the collar to the freezer when it is fully assembled.
You’ll want to re-use the gasket from the lid. Be sure to use the measurements of the gasket (perimeter) to determine the size of your collar (perimeter). This will assure that you can reuse the gasket, and assure that you will have a collar that is capable of providing a proper seal. In essence, build your collar so that the dimensions match that of the gasket you previously removed from the lid.

#3. Be sure to measure properly and take into consideration blade kerf when cutting your lumber to length. For a nice clean build, be sure to cut your (4) sides (8 ends) using 45 degree angles so that you have no end grain showing when the build is complete.

#4. Secure all four sides of your keezer collar by drilling pilot holes and installing two wood screws in each corner. For added strength, you can also opt to add corner gussets to strengthen the structure. Keep in mind that soon you will be attaching this collar directly to the underside of the freezer lid that you removed in Step #1 which will provide some inherent structural stability.

At this time, you can utilize a hole saw to drill the holes that will accommodate the shanks for your taps. This can also be reserved for later. You can also sand, stain, laquer or otherwise prepare and preserve the wooden collar. This will not only protect the wood, but it can also add an aesthetic dimension to the keezer as well.

#5. You must secure the collar to the underside of the lid of the freezer. This can be done with a combination of “L” brackets and construction adhesive. Both will provide excellent holding power, but the combination of the two will provide positive holding power as well as the ability to seal the area where the collar meets the lid with an air tight seal.

#6. Install the gasket that was removed from the lid in Step #2 to the bottom edge of the collar, or the ledge of the freezer. This can be accomplished with the use of a good construction adhesive.

#7. Finally, you will want to mount the hinges that you removed from the freezer/freezer lid, to the collar itself. This will now allow the collar (and taps) to swing up and out of the way when you open the keezer for routine maintenance and cleaning.

This post was originally written by The Pol from HBT (one of the Brewer’s Friend authors) way back in 2009! We were cleaning out the archive and realized it had not been published. Doh!  The same facts hold true today about Keezers as they did in 2009.

Hope you enjoyed the article and are inspired to keg at home and build yourself one.

Posted in Equipment, Kegging and CO2 | 4 Comments »

Printable BIAB Checklist Launched

One of our fellow brewers wrote in awhile ago asking for a printable Brew In A Bag (BIAB) checklist, similar to the current All Grain Printable Checklist, but tailored to BIAB.

Here it is:

BIAB Brew Day Checklist – Printable list of steps for brewing using the BIAB method.

For more information on what BIAB is all about:

• Brew In A Bag (BIAB) All Grain Brewing Method
• BIAB Custom Bags You Can Order, and Example DIY False Bottom

Posted in Announcements | No Comments »

Removable and Reusable Labels for Home Brew Bottles

The other day I realized, my home brew bottles are naked! They don’t have fancy labels like all those commercial beers do… I hope they don’t feel embarrassed when I take them to a friend’s house. I’m lazy and just write one or two identifying letters on the cap with a sharpie. H = Hefe, PA = Pale Ale, S = stout, etc… It’s ghetto but it works.

Why I don’t normally label:

A) Labels take time to make.

B) Since I re-use my bottles, that means eventually having to peel off the label. With a standard label, that requires warm water, soap, a scrubber, and some elbow grease. What a pain!

The solution I would need for it to make sense to label my home brew more often:

A good looking label that goes on and stays on, but then easily peels off and can be reused multiple times. Here comes BeerClings to the rescue! The owner of Beer Clings contacted us about their product and sent us a free sample to play with. Pretty neat idea, and it really makes that naked home brew bottle look ready for a night on the town. The label stays on great – even weeks later! It peels off easy, and goes back onto the original sheet with out a problem.

The makers of the Beer Cling are well aware they need to come out with lots more templates, and allow brewers design their own logos.

There are two aspects to labeling:

One is the aesthetic component. Home brewers are proud of their beer (at least the good batches). Decorating the bottle with a label is a nice touch. We’ve tested doing wax seals on the caps, that is fun but a bit of work. BeerClings helps to address this, and once they get more patterns to choose from, for only $5 per sheet, I think they will be in a great niche.

The second component to labeling is record keeping. Knowing what is in the bottle is good. Especially if you are taking it to a club and passing it around.  Knowing the IBU, SRM, ABV, OG/FG, style, and who brewed it is even better! This goes for Kegging beer too! I use post it notes to keep track of which keg is which, again the bare minimum. It would be nice to have the ABV and IBU on a label posted right on the keg (or by the tap).

How we are going to support labeling:

Here at Brewer’s Friend, we are looking into supporting label making in some fashion. There is a thread in the forum going on about labeling. There are several links in there and ideas from fellow brewers on how they label their bottles.

At the very least, the recipe editor should have a button to generate text from the recipe that can be copied and pasted into Word or Open Office. It would be nice to include the recipe name, style, and stats like IBU, SRM, ABV, etc.  I just ordered a set of Avery removable labels to play with. That would be best of both worlds – the ability to print whatever you want on the label, and the ability to remove it easily when the bottle is empty.

One last thing I thought was cool, BeerClings also makes these wooden prohibition style crates (I want one):

Post by Brewer Larry

Posted in Equipment, Fun | 2 Comments »

September 2012 Release is Live

We just launched a bunch of features!  We are proud to say that many of the updates in this release came directly from topics in the feature request forum.  In addition, we made a nice improvement to the brew feature so it reports Pre-Boil Efficiency in addition to Brew House Efficiency.  We also made some major headway towards our first mobile release and group brewing feature (not ready yet). We also did some bug fixes and back end work to keep the system running smoothly.

Recipe Editor:

• Ability to add grains in pounds or ounces (or Kg/g for Metric recipes). Ability to add hops in ounces or grams, regardless of units.  Click on the units label with the little triangle, it works like a drop down box. [Forum thread]
• Under the “More…” button, each stat / equation now has a visual ‘matches style’ indicator. An exclamation point is displayed if the value is out of range, or a green checkbox appears if it matches. [Forum thread]
• Ability to set default hop type under your profile. Saves time if you typically use pellets.

Brew Sessions

• Pre-Boil Efficiency measure introduced (read more about that below).
• Default sort on my brew sessions page set to a more sensible default, and ability to hide completed batches. [Forum thread]
• The brew log entry screen now anticipates the next type of log entry.

Yeast List

• Corrected Wyeast NB NeoBritannia 1945, had wrong number.
• Added the new Danstar BRY-97 yeast. Larry will be using this in his Snifter Grade IIPA (experimental) batch as soon as it comes to the home brew store!

Thoughts on Efficiency:

We have been doing a lot of research on the meaning of efficiency in brewing. Deep thinking, the kind that keeps you up at night. The kind that that gives you dreams like flying on kettle lids through skies filled with clouds of steaming wort, swimming in a giant sized mashed tun, and coding equations from inside a grain husk.

Brewer’s Friend uses Brew House Efficiency (as defined here) in the recipe editor. This can be thought of as ‘to the fermentor’ efficiency. All losses that do not make it into the fermentor are counted against this measure. This is good because it provides a realistic picture of your entire system’s performance, which is what you need to know to brew repeatable batches!  If your friend tells you they get 85% efficiency – ask them which type of efficiency.  That is probably their conversion efficiency or their lauter efficiency, but not their efficiency to the fermentor.  Repeatable efficiency is what really matters. Please be aware that recipes with more hops than normal will cause greater hops absorption losses, thus lowering Brew House Efficiency by ~1%.

As part of this release, we have just introduced a new efficiency measure: ‘Pre-Boil Efficiency’ – the percentage of total available sugars that made it into the kettle.  It can also be thought of as lauter efficiency. Volume losses from mash tun dead space and grain absorption count against this measure.   Those of you who have been diligently making ‘Pre-Boil Gravity’ log entries will automatically see this figure computed on your existing brew sessions.  This number is generally 8-10% higher than Brew House Efficiency, since it does not count trub losses and kettle dead space.

We are working on adding ‘conversion efficiency’ in the near future, which looks only at the efficiency of the extract in the mash tun, before any draining takes place. This number is always the highest.

Well, that’s all for now.  Happy brewing!

Posted in Announcements | 2 Comments »

Hops Harvest Complete

The 2012 hops harvest is complete! Everything is packaged and dried.

The process is to first harvest the hops by hand picking. You can cut the vines down, but this year I decided to leave them up and use a small step ladder to reach the higher cones. My advice is to only harvest one variety at a time and keep track of where each variety is in the picking / drying / packing process.

Then you want to let the hops dry for about 48 hours, until they are no longer moist to the touch.  I weighed a few of the samples before and after. There was about a 50% reduction in weight. This runs counter to the advice of using 4-7 times the normal amount when brewing a fresh hop beer…

The false bottom came in handy for the smaller crops:

When they are dry, weigh them out for packaging.  One of my recipes calls for 2 oz of Chinook, so I weighed out that amount for that particular bag.

A vacuum sealer is a wonderful tool for this process.

I then label the bag, and put them in the freezer.

The inventory feature at the site helps me keep track of what I have.  I wonder if I will ever get around to using that 2010 Willamette??

Here is the breakdown of what I got, and the order harvested in. It seems like Kent Goldings is always latest in the season to harvest.

• Chinook – 10.5 oz
• Hallertau – 10.2 oz (two vines)
• Cascade – 2.2 oz
• Zeus – 2.2 oz
• Fuggle – 2.9 oz
• Magnum – 1.6 oz
• Nugget – 7.7 oz
• Goldings – 5.25 oz
• TOTAL:  42.5 oz = 2.65 pounds, @ $2.00 per ounce retail – about $85 dollars in hops, I’ll take it! You can beat the price of $2/oz if you buy in bulk.

Post by Larry

Posted in Hops Growing | 5 Comments »

Chain Mail For Cleaning Stainless Steel

Yes, that’s right! Chain mail has a practical use in the brewery!

In addition to brewing, I enjoy cooking. In fact, I see brewing as an extension (a BIG one!) of my cooking. Early this year, one of my favorite cooking magazines – Cook’s Illustrated – reviewed a cleaner for cast iron. It’s called the CM Scrubber, and the CM stands for chain mail! It had been recommended by a few readers and the magazine’s editors decided to evaluate it. They liked it very much, and I ordered one immediately. After a bit of a wait (each is made in the US by hand, plus their orders exploded after the article) it arrived in the mail. Here’s what it looks like:

We’re a mostly cast iron cookware house. It’s heavy but the even heating can’t be beat! I’ve been using it frequently on our cast iron. Knappmade, the manufacturer of CM Scrubber, mentioned it also works well on stainless steel cookware. I began using it for that purpose and was equally happy with the results.

Recently I was washing my “well worn” stainless brew pot after a brew session. I had a moment of inspiration and decided to try the CM Scrubber and Bar Keeper’s Friend and see if they could shine my brew pot up a bit. If you haven’t seen it before, here’s what the label looks like:

A bit of history about this humble brew pot – I bought it used from a Craigslist ad. It had been well used by other brewers by the time I purchased it. There were dings and scratches when I bought it, and original owners of the pot used a “turkey fryer” type propane burner which leaves stains of its own.  I’ve had it for 3 years and use it on the stovetop about twice a month. Bottom line: well used with battle scars to prove it!

While I keep my equipment clean, I’m not obsessive about hot side brewing stuff looking absolutely perfect – a different story on cold side. I only spent no more than 5 minutes scrubbing on the bottom panel, absolutely less than 10 for the whole pot.

Here’s the “before” – I chose the bottom of the pot to photograph because it was the most stained compared to the inside.

Using Bar Keeper’s Friend is easy, it sprinkles out like Clorox or Bon Ami that are packaged similarly. It’s a slightly cakey white powder. You add a bit of water and you scrub. Here’s the start of cleaning with the cleaner sparingly sprinkled on with just enough water to dissolve it. You can see some undissolved cleaner caked up on the lower right of the pot:

So, I scrubbed the bottom. I used some elbow grease, but not much is needed. As with my cookware, the CM Scrubber does most of the work. I used the last few minutes to scrub the inside out using the same process.

Here’s the “after” – much improved!

The inside of the pot was much improved as well! Based on the result I’ve now added a quick CM Scrubber and Bar Keeper’s Friend pot cleaning step to my routine. If you’re interested in learning more about the CM Scrubber, here’s a link to their website: https://www.cmscrubber.com/

Post By Brewer kcpup

Posted in Equipment | 1 Comment »

Wildflower Wheat Tasting Notes

I wanted to follow up with some tasting notes on this recipe and blog post. Here’s a photo of a pint – note that the head had fallen in the time it took to pour from my keezer, bring the glass up from the basement, set it down, and snap a photo.

Appearance – Pours a deep, orangy golden color with a fluffy two finger head and respectable retention. Head retention, however is not like a Hefe. Hazy as a wheat beer should be.

Aroma – First impression is a distinct fruity, floral aroma – not from hops, but from the chamomile. Deeply fragrant, with a nod to a malty wheat background. If you hate chamomile you’d get turned off, fast! No detectible hop presence. Overwhelmingly chamomile. I used a clean American yeast (Pacman), so I don’t detect any yeast character in the nose. Not much honey in the nose, but I wonder if some of the powerful aroma is the honey in the background that isn’t distinctly detectable.

Taste – Rich flavor. A blast of chamomile!  You can taste the wheat beer character behind the chamomile and honey. There is some honey character as you get past the initial blast of chamomile. Pacman is a high attenuator, and my FG was lower than the recipe specified – more of the honey was fermented out. Despite the pleasant dry finish, this is a flavor powerhouse. Serious character – this beer has a definite point of view. If you like chamomile, it is an easy drinking, highly flavorful beer.

Mouthfeel – I carbed to 2.5 volumes and that was sufficient. Mouthfeel is medium – not light and airy, but not heavy, either.

Drinkability & Notes – This beer was warmly received by craft and non-craft beer drinkers alike. Most of the keg was consumed at a big party. People were stopping me and saying how great the beer was. The non-craft beer drinkers guzzled this. I didn’t specify what herbs, etc were used in the beer. Most people who tasted it were completely uneducated on what beer it was and so forth, and it was widely accepted. That said, I was disappointed there was not more honey flavor. I think that was primarily due to using Pacman, which is an aggressive attenuator. When brewing this again, I plan to use a yeast with lower attenuation to see if I can nurse out more honey character in flavor and aroma. I will brew this again, although this recipe will not unseat Belgian Wit as the number one wheat beer in the house. Overall I’m satisfied – I wanted a different wheat beer for a while, and this did fit the bill and turned out to be a good party beer.

Post by Brewer kcpup

Posted in Beer Styles | 1 Comment »

The White House Releases Beer Recipes!

The wheels of Washington’s political bureaucracy have turned.  With only 12k of the 25k signatures needed on the formal petition, the White House released the beer recipes to the public. These are very straight forward extract batches that can be done with a basic brew kit on your stove at home.

We loaded them into Brewer’s Friend:

Honey Ale
Porter

There were a couple minor details to fill in, such as the bittering hops used in the Porter recipe, or what type of Crystal malt is used in the Honey Ale.  Even so, this will get you pretty close to the results. It is likely they didn’t use Brewer’s Friend to track the brew, so maybe they don’t know either!

Posted in Announcements | No Comments »