Insulated Mug Tests, 2012/03/18

Purpose:
My pottery mugs don't keep coffee hot long enough. Basically 20 minutes and the tea/coffee is cold. So I thought I'd do some experimentation.
I was looking for two things:
- maximum time for a traditional open top mug (no lid) that I could use routinely and perhaps serve guests, and
- maximum time for anything you could drink out of with one hand, i.e. a lid with a slurp hole. (unlike say a 1960s coffee/soup vacume glass Thermos, where one has to pour it into the screw on plastic cup).

I make no claim about suitability to any use, or how long they will last.
e.g.
- if you can actually drink out of the things
- if they'll spill in a backpack, or in your car
- if they will survive multiple washes in the dishwasher
- if they will survive more than a few months. #12 for example has some nasty pictures at amazon with the paint coming off after a couple months.
- there's a complaint at amazon about #5 letting water in through the silicone stopper at the bottom
- #6 Trudeau doesn't have a drink hole, so you have to peal the lid off every time, or drill your own hole
- #11 is rated "staff pick" at Kitchen Stuff Plus, and is listed as 'best' at Hammacher Schlemmer. I think it's pretty good too, but I'm not sure if the lid will clean well with coffee with milk. #12 has basically the same lid. Supposidly they come apart into a half dozen pieces for better cleaning, but I haven't tried.

All I tested was how long it would keep a cup of water hot.

Apparatus
- measuring cup (1 cup)
- kettle to boil 13 cups of water
- meat thermometer
- 15 minute timer

Method:
Each went through the dishwasher at least once, whether they were dishwasher safe or not. I used Finish Gelpac All-in-1 Orange as soap, because I've found powders like Cascade leave powder on the inside of my dishwasher and dishes. I set the dishwasher to {Normal Wash, Heated Wash, and Sani Rinse} but no heated dry, and they were on the top shelf.
I boiled water in the kettle (or pot), and used the measuring cup to put one cup of boiling water into each. Every 15 minutes I'd remove the lid (if applicable) and put the meat thermometer in and record the temperature on paper.

Observations:
#2, #3, #4 all have a stainless steel interior. I also left bottled water in each for 24 hours, and when I taste tested it after that I think I could taste the steel.
That didn't happen with #5.

Conclusions:
- Category "traditional open mug": best is #5 Bodum Bistro Double-Wall Insulated 10-Ounce Glass Mug
- Category "tumbler with lid": best is #11 Thermos Premium Double Wall Travel Mug Without Handle


Products Tested (pictures not to scale)

1 Earthen Vessels Pottery Mug. Non insulated. (Kevin and Corina) 400ml. here ?
2 Stainless Steel Desk Thermal Mug, 400 mL 5.32oz (Product #42-2458-0) High-quality thermal insulation keeps liquids or food hot/cold for hours. Stainless steel construction for durability. Tight-fitting snap-lid for insulation. here $8.39
3 ThermoCafe® Stainless Steel Desk Mug (Product #42-8966-4) Foam insulation keeps liquid hot for approximately 90 minutes. 443 mL capacity. (7oz) Leak-resistant lid. Coloured stainless steel interior and exterior, in red or blue here $12.59
4 ThermoCafe® Plastic Mug (Product #42-8965-6) Double-wall vacuum insulation keeps contents warm for hours. Durable stainless steel interior and rim. Heat-resistant, comfortable, easy-grip handle. 500 mL capacity (7.1 oz) here $9.99
5 Bodum Bistro Double-Wall Insulated 10-Ounce Glass Mug, Set of 2. Winners of the 2007 iF Product Design Award, the Bistro Double Wall Glasses are available in several sizes, perfectly suited for a multitude of hot and cold beverages as well as desserts. Handmade of heat-resistant borosilicate glass, these vessels insure that their contents will remain hot for a longer period of time while the glass itself remains cool to the touch. They are dishwasher and microwave safe. The coffee andf tea mugs come as a set of 2 and hold 310ml (10 oz.) here $39.99
6 Trudeau dSeries 16-Ounce Desk Mug, Grey Keep your drink warm with the Trudeau dSeries Desk Mug. The innovative 360 degree, drink from anywhere on the lid design prevents spills and makes it incredibly easy to enjoy your favorite beverage while doing almost any type of activity. Double wall insulation means that your beverage will stay hotter or colder, longer. Rated 2-hours, heat retention. Other features include a convenient comfort handle and a non-slip base. Made to last; interior made of stainless steel and exterior made of nearly unbreakable SAN. 16-ounce capacity. Grey finish. Five year warranty. By Trudeau a company that develops visionary products. Add an exciting flavor to your day, with Trudeau. Style eloquence, innovation Trudeau letting you savor life's little moments. here $13.00
7 Contigo Auto Seal Double Wall Tumbler - Stainless Steel. Easy push and release button to stop the flow of liquid. Keeps drinks hot or cold for hours. Contoured shape makes it easy to hold on to. Double wall vacuum insulated. here $29.99
8 Starbucks 20oz tumbler. I went to a local starbucks, and asked what the most insulating thing they had was, and a young man who'd tried them all said this was the best partially because it had a solid lid that didn't leak when it fell upside down in his backpack, and that solid lid kept the steam and thus the heat in. $35
9 Tim Hortons Travel Mug Green. For the on-the-go coffee lover, our green travel mug showcases a peaceful nature scene and offers an environmentally-friendly way to enjoy hot Tim Hortons beverages. 15oz. Please be assured that our travel mug does not contain Bisphenol A (BPA). Our travel mug is made of polypropylene resins (PP - #5 plastic) but because it contains a layer of insulation (polyurethane foam - PU) between the inside and the outside PP layers it must be labeled with the #7 symbol meaning a multi-layer combination. Our travel mug does not contain polycarbonate or BPA. here $8? Comes with a free cup of coffee.
10 Tim Hortons Thermos Tumbler 15 oz. This Stainless Steel Tumbler from Thermos® has double wall insulation to keep beverages hot or cold for hours. (Merchant SKU: 15076) Stainless Steel Travel Mugs from Thermos® Our 15 oz. Stainless Steel Thermos® Travel Mug and Tumbler feature a spill-resistant, slide-lock lid that easily snaps into place. The unbreakable stainless steel interior & exterior construction keeps your favorite Tim Hortons beverages hot or cold for hours. The contemporary design ensures it fits most automotive cup holders. Available with a handle (Travel Mug) or without (Tumbler). here $13.95
11 Thermos Premium Double Wall Travel Mug Without Handle. STK# 67034 Unbreakable stainless steel construction. Vacuum insulation technology for maximum temperature retention. Keeps liquids hot for up to 5 hours. Keeps liquids cold for up to 9 hours. 360° lid. BPA free lid. Leak-proof lid with push button operation. Resists stains. Built-in tea hook. 480 ml. 16 oz. here $29.99
12 Thermos SK1005MBTRI4 Stainless King 16-Ounce Leak-Proof Travel Mug (Midnight Blue). The Thermos brand is well known as the quality and performance leader in insulated food and beverage products. The Stainless King series creates a new chapter in Thermos' storied history with a modern line that blends our newest technology with a dash of the past. The Stainless King Food Jar has TherMax double wall vacuum insulation for maximum temperature retention, hot or cold. The unbreakable stainless steel interior and exterior keeps drink cool to the touch with hot liquids and sweat proof with cold liquids. The Leak Proof Mug has a Capacity of 16-ounce/.47L. here $23.96
13 Canadian Thermos 290mL Food Jar (Product #42-4509-8) Stainless-steel outer shell. Satin finished exterior. 290mL capacity 5 hours hot, 7 hours cold here $28.29



Observations Test #1. Temperatures in degrees Celsius (0 is freezing, 26 is room temperature, 100 is boiling)

# Photo Comment 0 minutes 15 min 30 min 45 min 1 hour 1 hour 15 min 1 hour 30 min 2 hours
1 85 56 45 40 36 32 29 27
2 lid on 90 70 65 60 53 50 47 42
3 lid on 90 70 65 60 54 50 48 42
4 lid on 90 75 66 60 54 51 48 42
13 lid on 90 82 80 78 74 72 70 64



Observations Test #2. Temperatures in degrees Celsius (0 is freezing, 26 is room temperature, 100 is boiling)

Note: Instead of using a kettle I used a pot to boil the water, and the starting temperature of the water in each may not have been the same.
Overall, I'm not happy with the quality of test #2 because of the variance in the starting temperatures, so I stopped at 1 hour.
# Photo Comment 0 minutes 15 min 30 min 45 min 1 hour 1 hour 15 min 1 hour 30 min 2 hours
1 70 50 40 35 32
2 lid off 75 52 45 38 32
3 lid off 75 52 45 38 32
4 lid off 77 55 47 40 37
5 mug exterior warm at 30 min 80 58 50 42 38
6 mug exterior hot at 15 min, lid on 80 65 58 50 47
7 lid hot at 15 min, lid on 82 75 70 68 64
8 lid on 75 72 68 64 62
9 mug external warm 30 min, lid on 75 65 60 56 50
10 mug external hot 15 min, lid on 80 70 62 59 54
11 lid on 82 78 75 72 70
12 lid on 81 76 72 70 69
13 lid on 82 74 70 68 66



Observations Test #3. Temperatures in degrees Celsius (0 is freezing, 26 is room temperature, 100 is boiling)

Notes: Back to using the kettle again. Also I preheated all thirteen to 55 degrees in the kitchen sink for 15 minutes.

# Photo Comment 0 minutes 15 min 30 min 45 min 1 hour 1 hour 15 min 1 hour 30 min 2 hours
1 80 54 42 36 34 30 28
2 lid off 88 62 60 42 38 35 32
3 lid off 88 60 48 42 38 35 32
4 lid off 88 62 50 44 40 36 33
5 88 64 52 45 39 36 33
6 lid on 88 74 64 59 54 48 44
7 lid on 88 78 72 68 64 51 58 56
8 lid on 90 80 74 68 65 61 60 58
9 lid on 86 70 62 58 54 50 48 45
10 lid on 88 72 64 60 52 50 46 45
11 lid on 88 82 80 77 73 70 70 68
12 lid on 88 82 79 77 73 70 70 68
13 lid on 86 81 76 74 70 66 66 64