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 »

15 Minute Boil Tested

Earlier this year, a fellow named Brian reached out to us for a collaboration project. He’s a very cool guy, an award winning brewer, and happens to be the owner of The Brew Mentor, a home brew store in Mentor, Ohio. Brian had an idea that makes brewing easier for extract brewers who are pressed for time. The idea of a 15 minute boil is not new, but Brian has some twists on it and designed several recipes that fit best with the process.  We brewed around the same time, sampled our beers over the phone, and compared notes.

The idea is simple: get the best beer possible with only a 15 minute boil. This saves 45 minutes on brew day, and can cut the entire process to under an hour and a half. With a good chiller and refrigerated top off water, Brian got a 2.5 gallon batch done in 67 minutes:

9:17-  start, water from tap @ 78°
9:21-  water temp @ 155°
9:36-  steeping water down to 144° secondary wort almost boiling
9:38-  pull grains, combine worts
9:40-  add immersion chiller
9:45-  boil starts 10:01-  boil finished
10:07-  wort cooled to 95°
10:18-  finished in fermentor with yeast pitched

We did two different recipes. The first, dubbed Easy Blonde is a light sweet blonde ale that uses Amarillo – prefect for summer. The second is Pale Face, a smooth caramely beer with an amazing Simcoe aroma and flavor. We can confidently say that both brews turned out great! In fact, Pale Face won silver in a home brew competition! Don’t expect to impress your hop head friends with these beers. They are not bitter by any means, but in my opinion qualify as crowd pleasers.

This class of recipe is prefect for on the go people to brew up one evening a couple weeks before a tail-gater.  Football season is here!!!

What we learned:

1. A 15 minute boil can make decent quality beer within a number of categories. Don’t even think about doing an Imperial IPA with a 15 minute boil. Styles that are in reach with a 15 minute boil: Cream Ale, Scottish Light, Porter, Standard Bitter, English Mild, Fruit Beer.
2. Don’t expect much bitterness at all, but do expect the late addition effect to be strong.
3. The Rager equation seems a lot more accurate than Tinseth for a 15 minute boil.
4. 15 minute boil extract based brews are good enough to be competitive in home brew competitions!  Wow, we were not really expecting that.

What we remembered:

1. Ice baths suck. Get a chiller. You’ll love it.
2. Extract brewing is fast (and with a 15 minute boil blazing fast), and can make decent beer in a short amount of time.

I’ve never been so pressed for time when brewing. Ever time I turned around it was time to do something else. I’ve gotten accustomed to that nice slowdown period between the first hop addition at 60 minutes and the next (usually at 30 minutes or later).

To make up for the painful reduction in IBU levels, Brian is also working on an all grain, 90 minute boil American IPA called Bitch Slap.  At 125 IBUs and 9% ABV, that should compensate nicely for all the light beer we made lately!

For more tradeoffs in home brewing, remember when it comes to better, faster, and cheaper beer: Pick two and you’ll be fine!

Posted in Brewing | No Comments »

Summer Brewing Update

The first day of summer is right around the corner.  It is time for summer beers to be brewed and enjoyed. Usually this means choosing delicate aromatic hops, fruity yeasts, and shooting for a drier finish. Liquid refreshment here we come!

We played around with five different batches, each overlapping the other in some respect. Two of the batches use Kölsch yeast and two use American Hefe yeast. Two of the batches have noble hops (Hallertau and Tettnanger), while two use Citra and Crystal hops. The grain bills are pretty similar, consisting of Pilsner as the base malt, and a little Vienna and Munich. It will be interesting to see how the Kölsch yeast and the Citra hops combine vs the traditional noble hops.  Citra hops give an amazing mango like quality that should make for a refreshing crowd pleaser.

In my own humble opinion, the Spring Kölsch will be hard to beat. Being the traditional combination of all German ingredients, this might be expected. The Kölsch yeast provides notes of honey, vanilla, even a little smokiness, in just the right proportions. One downside of the Kölsch is it takes longer than other yeasts to clean itself up. Until about 45 days after the brew, there was a rubbery plastic taste. I thought it was from the Better Bottle, or a yeast health issue.  Turns out it was just green beer.

There is also a batch made with 100% Amarillo hops to show off the grapefruit aroma and flavor profile it provides. This batch was done in collaboration with Brian from the Brew Mentor in Ohio. When the results are in on that batch we’ll be doing a blog post to explain the new twist on brewing Brian came up with.

Summer Beer Recipes:

• Autobahn Hopped American Hefe
• Summer Citra Kölsch – An Experiment
• Aaron’s First Brew
• TBM Easy Blonde 15 (Larry’s)
• Spring Kölsch

One summer evening we will do a blind tasting to evaluate the results. We always add in a cheap macro brew just to make it entertaining. I wonder what we will mix in this time, maybe a little PBR? Our tasting sheet is simple enough that even novice beer drinkers can have fun too.

Blow off Tube Needed:

Here’s what happens when you don’t leave enough head space in your primary fermentor:

The yeast shoots everywhere!  Bit of a sticky mess, but all it takes is replacing the air lock.  A blow off tube is the best solution.

Other News:

• Site updates have been ongoing.
• The mash calculator and water chemistry calculators are now built into the brew session.
• Grain lists have been updated on all calculators.
• The site renders correctly at any width and works smoothly on smart phones and tablets.
• We just did a Brew In A Bag (BIAB) style batch. That was awesome, learned a lot. Complete details on that next time.
• A yeast pitching calculator is on the way!

Posted in Brewing | 3 Comments »

First Brew Adventure

Post by Brewer Aaron:

Brewing my first batch of beer today —a hefewiezen with citra hops— only solidified the wisdom that failure is good, especially the right kind. In this case, my first brewing experience was fraught with failures, but ones that we were set up to recover from gracefully and learn from. So here they are, the things I learned from brewing my first batch of beer.

1. Your recipe will be changed during the brewing process. At least for your first batches, you won’t be able to follow your recipe to the letter, but don’t worry, as long as you follow it closely, it shouldn’t screw up your beer too much. Especially try to know which items need to be striclty followed, and which have some wiggle room.

2. If you’re cooking on a stove, make sure your favorite burner is clean and ready to go. The burner I started my steep on started smoking, so I had to move it to a back burner. This made it hard to reach both the kettle, and the dials on the stove, a complication that would come back to bite us later. Also, if your stove doesn’t have a fan (yay 1970’s building codes!), you’ll soon learn where your smoke alarms are.

3. Start with less water rather than more. This may only apply to an extract brew with steeping grains, but if you’re using a smaller kettle, as I was, it’s nice to have a little more room for grains and hops. I learned this the hard way, when my brew boiled over. Which brings us to the next item…

4. Have some contingency plan for a boil over. In my case, I got the kettle off quick enough, with a very minor burn on my hand, and no brew on the floor. But you should either have a way to safely move the overflowing kettle off your heat source, or have a heat source that you don’t care about covering with burnt brew. In my case my brew fell on the element, making a big caramelized mess.

5. Buy some extra hop/grain bags. They’re cheap, you’ll use them. Larry suggested I do 4 hop additions, which would have been nice, but I only had two. Not a huge deal, but it would’ve been nice to have the flexibility.

6. The time elapsed in your boil matters less than the time left. I don’t really know when I dropped in my first hop addition, but I do know I waited 20 minutes later for my second, and 40 minutes later to end my boil. Here is my ice bath:

7. Be extra careful with your gravity meter (hydrometer). Yup, about 5 minutes after talking about how breakable they are with Larry, I broke it. That’s why it’s nice to:

8. Have an extra bucket.  Useful for keeping sanitizer solution on hand.

9. Shake up your wet (liquid) yeast before opening the package and pouring it in. If anything, it will make you feel a little less dumb when you’re left with a vial coated in the stuff that should be making your beer.

10. When topping off your fermenter to a certain amount, stop filling every so often, and let the foam settle. In my case, I didn’t, so now I’m brewing 6 gallons instead of 5.

11. Have some vodka around the house, in case you need to top off your airlock. Yup, mine wasn’t filled enough, so Larry suggested this trick.

12. You don’t need your bottles ready on the day of brewing. I knew this. I’ve helped other people brew, but for some reason that didn’t stop me from having them ready. At least they’re pretty in my dishwasher.

13. Your Airlock will be noisy. You’ll be surprised by how loud the bubbling is, but it’s a nice reminder of how awesome you are for brewing your own beer.

So now I’ve got 6 gallons of American Hefe brewed with Citra and Crystal hops in the fermenter. I’ll post back to let you all know how it turns out!

Posted in Brewing | 2 Comments »

Myths About Electric Brewing Dispelled

Personally, it has been eight batches since the upgrade to electric. The electric brewery is just awesome. There have been zero leaks on my weld-less fittings and no problems with operation.

Going into the upgrade, there were a few myths I was concerned about. Let me tell you the facts:

You can only do dark beers with electric brewing because the element will scorch the wort.

This is completely untrue given the right equipment. My first batch was a 3.2% Hefewiezen came out perfect. Subsequent batches, including an American Lager (arguably the lightest beer in the world) also had no scorching. In essence, expect ZERO scorching using the HighGravityBrew elements. If you build your own controller, or use a different element, this could be a problem.

The electricity is expensive.

According to our calculations electricity reduces the energy cost by 70%!

Equation for electricity consumption in home brewing:
hours * (watts / 1000) * price/kWh = total cost
For an example, let’s say the the price is $0.12 / kWh, and a typical batch is brewed:

• 1 hour * (5500 / 1000) * $0.12 = $0.66 (hot liquor tank 5500 watt element)
• 1 hour * (4500 / 1000) * $0.12 = $0.54 (boil kettle 4500 watt element)

Total electricity cost for a standard batch of beer: $1.20

A 5 gallon tank of propane is around $20 to fill, and you get at best 4 batches out of it. That puts the cost around $4/batch with propane.

It requires an expensive computer controller.

Yes and no. You can ‘build your own’ controller out of parts for under $100. That would also require knowledge of electronics. The one from HighGravityBrew is a turn key solution. Most electric brew rigs also have fancy controllers to automate valves and pumps in addition to controlling the electric element. This goes way beyond the issue of switching from gas to electric for a heat source. Besides, at that point it becomes a labor of love. As long as you are having fun and your wife is okay with the project, go for it!

My submersion chiller won’t work.

This is true. I had to adopt my chiller to look like this so it would straddle the heating element. Cools faster and looks interesting. One online reviewer said it looked like the Flying Spaghetti Monster!

I was against upgrading to a plate or counter flow chiller. That style of chiller leaves a lot of hot wort sitting in your kettle while they are draining. This is not good. Plate chillers are also a bear to clean without using caustic solutions.

An electrician is needed:

Actually, this is true. Pay for a licensed electrician and get the permits to make sure your brewing area is safe. Don’t electrocute yourself or burn the house down! All you need is a dryer outlet on a GCFI’d breaker.

Posted in Brewing | 7 Comments »

How long does it take to brew a batch of beer?

Brewing beer can take as little as two and a half hours for a simple extract batch and up to six hours for a complex all grain recipe. It is not a good idea to rush anything in brewing. Cutting back the boil time is not feasible because that time is needed to convert alpha acids in the hops into the bittering flavors they provide. Similarly cutting down mash time leads to lower efficiency. These are things we just can’t get around in the process. Below is a breakdown of our estimate on how long it would take brew a batch of home brew given different methods.

Extract Batch without steeping grains:

• 30 minutes – setup, and wait for water to boil
• 1 hour – boil
• 30 minutes – cooling, fill primary, pitch yeast
• 30 minutes – clean up
• 2 hours 30 minutes total.

Extract batches are the fastest because there is no mash to worry about and less equipment to deal with.

Extract Batch with steeping grains:

• 30 minutes – setup, and wait for water to warm up
• 45 minutes – steep grains
• 15 minutes – wait for boil
• 1 hour – boil
• 30 minutes – cooling, fill primary, pitch yeast
• 30 minutes – clean up
• 3 hours 30 minutes total.

Steeping grains add real flavor, color, and freshness to plain extract batches. The extra time in our opinion is completely worth it, and the differences will be noticeable.

All Grain Batch:

• 45 minutes – setup, and wait for mash water to warm up
• 1 hour, 30 minutes – mash
• 15 minutes – wait for boil
• 1 hour – boil
• 30 minutes – cooling, fill primary, pitch yeast
• 30 minutes – clean up
• 4 hours 30 minutes total.

All grain brewing does take longer. Complete control over the ingredients and mash leads to noticable benefits in the finished product.

All Grain Batch with 90 minute boil and longer mash:

• 45 minutes – setup, and wait for mash water to warm up
• 2 hour, 30 minutes – mash
• 15 minutes – wait for boil
• 1 hour 30 minute – boil
• 30 minutes – cooling, fill primary, pitch yeast
• 30 minutes – clean up
• 6 hours total.

Some brews, particularly those using a large amount of Pilsner malt use a 90 minute boil. Longer mash times can also lead to higher efficiency.

Other thoughts:

One way to save on setup/tear down time is to have a dedicated brew space, like a shed. This takes time to build up to, but it is really nice to have.

Does time really matter when it comes to home brewing? If you are enjoying yourself that is what matters. Brewing is stress relief.

Posted in Brewing | 2 Comments »

Infected Batch Forensics

For the first time in many years I experienced a bad batch of home brewed beer last month. I am sharing this with the community so you can avoid my mistake. It is embarrassing! Being out the time and money for the batch and having an empty keg sucks. However, I learned a couple things I can pass along. This bad batch changed my perspective on yeast re-pitching, updated my definition of what a healthy fermentation is, and helped me clean my equipment better.

The spoiled batch, which had been in the keg for about 2 weeks had the following properties:

• Initial flavor was anti-septic (almost burning).
• Murky appearance (different than chill haze).
• Slippery mouth feel.
• Finshed soapy, with the flavor getting more pronounce, to the point I spit it out. The bitter antiseptic flavor lingers on the tongue.

What the heck! Had I gotten a lax on sanitization? Was my yeast bad? Was there something in the brewing process that lead to this? I asked some home brewing experts and they attribute this to a yeast deficiency – either an infection, or bad yeast. It turns out there were two main factors, repitching of yeast and a dirty spigot in my fermentor. While I am not sure which did more damage, I have evidence of both.

Here is what the carboy looked like, note the ring:

If you have a goopy ring around the krausen layer you might be in trouble. The off gases from the fermentation also smelled ‘cheesy’, which tipped me off there might be a serious problem.

Beer Forensics:

For what turned out to be the spoiled batch, I opted to re-pitch yeast (Wyeast Northwest Ale 1332) from a previous batch of IPA. The harvested yeast was in the fridge in a ball jar for about 2 weeks. That IPA was already in the keg and was drinkable, but it was not my best batch ever. It had a thin finish and there were some light ‘chemical’ flavors present that come and go from sip to sip. I figured at the time, the beer was just green – and it did improve a lot after a month went by. When I kegged the IPA and harvested the yeast, it looked and smelled fine, a fresh bready aroma was present. That meant it is good to go right? WRONG!

Something funny happened with the fermentation of that IPA. One night I forgot to set the furance at 64F, and instead turned it all the way down to 58F – so it got pretty cold in the house that night. It turns out NW Ale 1332 does best between 65F and 75F. In effect, that night the yeast were really stressed. I didn’t think much of it at the time. I do recall the fermentation slowed after that. I also left the IPA in the primary for 23 days, without racking, and then harvested the 23 day old yeast cake. In retrospect I should have spent the $4-$7 for a new yeast pack. Even though that yeast cake smelled good at the time, it was no longer to be trusted given its age, and the temperature fluctuation.

I gathered two ball jars from the yeast cake. Now a month later, on inspecting the second ball jar, there is a thin line of black mold growing on top. YUCK!

That IPA was fermented in a plastic bucket with a spigot. The subsequent failed batch was fermented in a glass carboy. I went ahead and tore apart the spigot on the bottling bucket, and look what I found in there:

It had probably been over 3 years since I setup that bottling bucket and spiot. Whoops! No doubt whatever mildew / mold / germ was living in there is not good for the beer. I terminated it with extreme prejudice – a strong bleach solution!

After I soaked everything, I thought I was ready to go again, but then I noticed, inside the sealed part of the spigot, there were some faint black spots. It is hard to see in the picture, so I enhanced the second one.

The mold / mildew, whatever it is, is growing INSIDE the sealed part where the spigot rotates. There is no way to scrub that section. I am looking into getting a different type of spigot that does not have this design flaw.

Yeast Re-pitching Revisited:

All this time I had thought I was being a good sport by re-pitching yeast. That is what the pro’s do right? Well, it turns out I did not realize the risks associated. I wrote an article awhile ago that praises yeast washing, and another on yeast repitching. I have updated those articles to point out what was learned here. The time it takes to harvest and clean the yeast (15-20 minutes), plus the risk is not worth the $3 savings it offers! I should have known that…

Key Take Aways:

• Yeast re-pitching can be risky and might not be worth the cost savings for home brewers.
• If you are going to repitch – I would rack after about a week and save that yeast. Let the secondary fermentation finish on its own, and discard that smaller, older yeast cake. I would also be very strict about temperatures ranges and sanitization. I successfully repitched many many times, but now I am starting to see where perhaps some inconsistency came into play.
• Tear everything apart now and then and completely clean it with PBW or a bleach solution if the materials are compatible with bleach.
• Look for stuff growing inside what appear to be sealed parts, such as the spigot on the bottling bucket.

PROST!

Posted in Brewing, Yeast Cultures | 9 Comments »

Electric Brewing Upgrade

Upgrading to electric brewing makes home brewing a real pleasure. This article covers the details, including a 30 amp GFI’d outlet, drilling holes, and ordering ~$280-500 worth of parts. Dave Knott at HighGravityBrew spent years perfecting electric brewing equipment for his own use. He sells everything you need online and through his home brewing store in Tulsa, Oklahoma. HighGravityBrew saved so much time and headache! I highly recommend their products and I am writing this article as an acknowledgement of their quality, and a thank you.

Heating Elements Used In Brewing:

With electric brewing a heating element is mounted inside the kettle. It works the same way an electric water heater works. Instead of heating the kettle from the bottom, the wort boils from inside. Here is how my boil kettle looks:

The elements can be purchased from HighGravityBrew:

For the HLT, they recommend a 5500 watt unit.

For the Boil Kettle, they recommend a 4500 watt unit.

Weld-less vs Welded fittings:

Getting the element into the kettle requires drilling a hole and using either a welded or weld-less fitting. Weld-less is a simpler option that worked well for me.

Step 1 – Drilling the hole:
This I did myself by carefully marking where I wanted the hole, relatively low in the kettle, such that the element would not hit my dip tube. On the mark, I took a center punch and made a dimple so the drill would have a place to slot into. Lots of oil, walled off with a damn made of plumber’s putty, and a standard hole saw made the cut in under a minute. For the HighGravityBrew elements a 1.25″ hole needed to be drilled. I spent some time fretting about the bit type. Some sites suggest using a stepped bit (aka unibit), but they are expensive. For the thin wall of my kettle (which was from MoreBeer / Polar Ware), a standard hole saw worked fine.

Step 2 – Fitting the element:

In the case of a welded fitting, a coupler is welded over the hole. The element slides through it and screws in to female pipe thread on the coupler. Welding shops were quoting around $75, plus the couplers.

The weld-less fittings use a silicone gasket and a stainless steel nut that go on the inside of the kettle. This approach was feasible to do on my own and cheaper overall. Zero leaks from the weld-less fittings after two brews.

Power Source:

A 30 AMP GFI breaker is required. Get it installed by a professional. My brewery has a 4 prong dryer outlet which the controller plugs into. The controller is described in the next section.

Controller:

To regulate the power going into the element, a controller is used. The controller plugs into the dryer outlet. The cord that leads out of the element plugs into the controller.

HighGravity brew has a couple turn key options. I bought the ECB II for $300. With this unit I can vary the power using the knob. The ECB II also has a bypass for a temperature controller. This allows the element to be turned on or off by a temperature probe. That way a HERMS system can be built with the ECB II as its heart.

HighGravityBrew also has a $200 model, which doesn’t not allow a temperature probe to be hooked up to it.

Wort Chiller:

I had to redesign my wort chiller so it would not sit on or bang up the element. My solution was to wrap another 50 feet of soft copper tubing around a 4″ PVC pipe and form it into the following:

Plate chillers and counter flow chillers are another alternative. I researched those quite a bit and decided against them. Stay tuned for an article on that.

Performance:

On the highest setting, the elements will increase temperature at the following rates:

• 15 gallons, +3 deg F / min
• 10 gallons,- +4 deg F / min

Strike water is ready in under 30 minutes. Going from mash out to boil takes under 10 minutes! After a rigorous boil starts, the dial can be set back to around 60% to maintain a steady boil.

In an electric brewery, the cost of boiling is measured in kilowatt-hours (kWh). In the northwest the price is around $0.10/kWh, but in Hawaii it is higher. Check your electric bill to be sure.

The equation is:
hours used * (wattage / 1000) * price/kWh = total cost

For an example, let’s say the the price is $0.12 / kWh, and a typical batch is brewed:

• 1 hour * (5500 / 1000) * $0.12 = $0.66 (hot liquor tank)
• 1 hour * (4500 / 1000) * $0.12 = $0.54 (boil kettle)

Total electricity cost for a standard batch of beer: $1.20

No More Propane:

Minimal cost savings aside, eliminating propane from the brewing equation is just awesome. Exhaust fumes are no longer a concern. There is no worry of a seal or hose coming loose and burning the shed down. Best of all, no more lugging the tanks around and having to get them refilled. If you are brewing indoors on a propane burner, seriously consider this upgrade. I have enjoyed brewing even more. I did not think that was possible. Electric brewing is safer, cheaper, and more environmentally friendly.

Posted in Brewing | 3 Comments »

Aeration Practices Simplified

In the interests of simplifying the brewing process I no longer aerate with an oxygen tank and stone! This saves the trouble of sanitizing the tube and stone each brew day. There is no worry of running out of oxygen, or keeping a second tank on hand. My tube is impossible to clean thoroughly because the stone is fused to the tube and water will not run through it.

(O2 tank is no longer needed!)

(Hose and regulator are no longer needed!)

The way I aerate is so simple it seems lazy. Just splash around the wort as it drains into the fermenter. The procedure is to occasionally shake the bucket or carboy as it is draining to build up a nice frothy head. It reminds me of early extract brewing days. Some people sanitize a large spoon and stir up the wort. Some people rock the carboy back and forth, I find that takes extra effort though.

In the future I plan to rig up a splash manifold at the end of the drain hose. It would be suspended above the wort level in the fermenter and cause the wort pouring in to go all over the place. Stay tuned for a future article on that. It should be a pretty cool looking gadget and cost next to nothing.

I am an all grain brewer, so aeration is especially important because of the full wort boil (which drives off oxygen). The last four batches I brewed have been aerated with the new lazy approach. I have noticed zero problems with fermentation time, attenuation, and flavor. Aeration in home brewing is over emphasized by some sources. There is at least one experiment showing it is okay to be “lazy” about it. The following test indicated little if any improvement with using an aeration system, vs shaking:

Link: Aeration Experiment Including Time Lapse Video of the Sample Fermentations

For a commercial brewery, monitoring exact levels of oxygen in the wort is important for quality control. Personally, I am not going to loose sleep over O2 levels in my brewing. This information will hopefully save some readers the $50 it costs for a basic aeration system, if not more in time and hassles.

Posted in Brewing | 10 Comments »

Alcohol By Volume Calculator Updated

The Brewer’s Friend ABV Calculator was just updated to include not one, but now two formulas for calculating ABV.  There are two popular formulas out there for calculating ABV.  You can pick the one you prefer for use in your brewing notes.   If you don’t like math, or don’t care that much, just stick with the basic formula. If you are super into math, and want to use the advanced formula (which is supposedly more accurate for high gravity beers), then the alternate equation is now there for you.

Standard Formula:

Most brewing sites use this basic formula:

ABV = (og – fg) * 131.25

This equation was created before the computer age.  It is easy to do by hand, and over time became the accepted formula for home brewers!

Variations on this equation which report within tenths of each other come from The Joy of Homebrewing Method by Charlie Papazian, Bee Lee’s Method, Beer Advocate Method. Some variations use 131 instead of 131.25. The resulting difference is pretty minor.

Alternate Formula:

A more complex equation which attempts to provide greater accuracy at higher gravities is:

ABV =(76.08 * (og-fg) / (1.775-og)) * (fg / 0.794)

The alternate equation reports a higher ABV for higher gravity beers. This equation is just a different take on it. Scientists rarely agree when it comes to equations. There will probably be another equation for ABV down the road.

The complex formula, and variations on it come from Ritchie Products Ltd, (Zymurgy, Summer 1995, vol. 18, no. 2) -Michael L. Hall’s article Brew by the Numbers: Add Up What’s in Your Beer, and Designing Great Beers by Daniels.

Why don’t calculators all agree?

1. The relationship between the change in gravity, and the change in ABV is not linear. All these equations are approximations.
2. Some calculators round internally as they go. The Brewer’s Friend calculator rounds only at the very end, which means significant digits are kept along the way (making it more true to the equation).
3. Other online calculators should be close to one of the two equations reported by the Brewer’s Friend ABV Calculator. If not, they are doing their own thing which warrants inquiry.

What equation should I use?

Your home brewing friends probably use the basic equation. If you don’t like math, go with the basic equation.

If you are a really tech heavy brewer, and want to brew a lot of high gravity beers, or prefer Daniels over Papazian, use the advanced equation.

Either way, they are close for beers below 6% ABV.   The difference does get larger as the gravity increases.   For a brew with OG 1.092, and an FG of 1.021, the standard equation reports an ABV of 9.32%, while the alternate equation reports 10.17%, that’s a difference of 0.85%.  At that alcohol level, after a few beers, maybe it doesn’t matter so much… hehe ;)

Prost!

Legal Disclaimer: The Brewer’s Friend ABV calculator is for entertainment purposes and should not be used for professional brewing. No warranty or guarantee of accuracy is provided on the information provided by this calculator.

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